February - Respiratory Care

February 1996
Volume 41, Number 2
ISSN 0020-1 324-RECACP
A MONTHLY SCIENCE JOURNAL
41 ST YEAR— ESTABLISHED 1956
Editorial
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Respiratory Care Education: Current
996 Open Forum Abstracts
Issues
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Final Deadline April 28, 1996!
A Commercial Standard
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Pulse
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Tracheal
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A New Teaching
Feature:
Cardiorespiratory Interactions
Cardiovascular Anatomy & Physiology
The Role
42"''
^
International Convention
November
3-6
•
San Diego, California
of
CRI
in
Respiratory Care
.
.
'
.
AARC's Professor's Rounds in Respiratory Care
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L
lies
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ook
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32
RE/PIRATOR\J CARE
A
Monthly Science Journal. Established 1956.
Official Journal of the .-Xmerican Association for
Respiratoo' Care.
Editor
Contents
BA RRT
Pat Brougher
19%
Number 2
February
...
Volume
41.
Associate Editor
Kaye Weber
MS RRT
Editorials
Editorial Office
11030 Abies Lane
Dallas
TX
98
75229
(214)243-2272
Respiratory Care Education: Current Issues and
Future Challenge.s
hy Lucy Kester and James
Editorial Board
James
K
Stoller
Ohio
Original Contributions
MD. Chairman
100
Cleveland Clinic Foundation
Cleveland, Ohio
Evaluation of a Commercial Standard for Checking
Pulse Oximeter Performance
by Teresa
Richard
K SlolU'i—Clcveiaiul.
D Branson RRT
A
Volsko. Robert
L Chatburn. and Thomas J
Kallstrom—Yoiingstown and Cleveland. Ohio
University of Cincinnati
Reviews. Overviews,
Medical Center
Cincinnati.
Crystal
L Dunlevy EdD
The Ohio
&
Updates
Ohio
105
RRT
Tracheal Gas Insufflation: Adjunct to Conventional
Mechanical Ventilation
A Ravenscrafl—Sl Paid. Minnesota
State Universit\
by Sue
Columbus. Ohio
Charles
G D tub in
Cardiorespiratory Interactions
MD
Jr
The University of Virginia
Health Sciences Center
1
1
Foreword:
by Barbara
Thomas D East PhD
LDS Hospital
Lake
1
1
Dean R Hess PhD
G
Wilson, Jon
N Meliones.
and John
M Pahnisano
Arbor. Michigan
Understanding Cardiorespiratory Interactions:
Anatomy and Physiology
by Charles A Trant. Frank H Kern, and Jon N Meliones—
Cardiovascular
Utah
City.
Teaching Feature for
—Durham. North Carolina and Ann
University of Utah
Salt
A New
RESPIRATORY CARE
Charlottesville. Virginia
RRT
Durham. North Carolina
Massachusetts General Hospital
123
Harvard Medical School
Neil
Duke
R Maclntyre
Jr
The Role of Cardiorespiratory
Respiratory Care
by Donald R Black. Barbara
Boston. Massachusetts
MD
G
Interactions in
Wilson,
and Jon
N Meliones—
Durham. North Carolina
University Medical Center
Durham. North Carolina
Shelley
C
Mishoe PhD
Books, Films. Tapes,
RRT
133
Medical College of Georgia
Pharmacology
& Software
for Respiratory
reviewed by Hugh S
Augusta, Georgia
Care Practitioners
Mathewson— Kansas Citx. Kansas
PhD RRT
Joseph L Rati
Georgia State University
Atlanta. Georgia
Respiratory Care
•
February
"96
Vol
41
No
2
83
Here^s one you^ve
really got to see!
The
New JCAHO
Their Effect
A Videotape
in
Hospital Standards:
on Respiratory Care
from the Professor's Rounds
Respiratory Core Videoconference Series
Featuring Nancy Telford, BS, RRT, Program Manager, Joint
Commission on Accreditation of [Healthcare Organizations, with
Moderator Sam P Giordano, MBA, RRT, AARC Executive Director
The new J995 Aaredilalion Manual
impact patient outcomes, and
llie
lor
Hoipilak
slondords ore
you
single chopter Ttirough this overview,
thon
competence progroms,
responsibilities of
is
now organized around
now
Pleose send
me
New JCAHO
"The
.Viso
and the
role of
directors,
department
and expectotions on perlormonce improvement.
staff.
Chorge
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90 minutes. Item VC51
Hospital Standards: Their Effect on Respiratory Care." Item VC51
Payment enclosed S_
Chorgetomy
learn about slondords reloted to
will
department leoders ond medical
This video olso reviews the inleroclive survey process
functions thai
integrated into functional diopters rotfier
Number
wbiecl to chonge without notice
$1
February 1996
Managing Editor
Ray Masferrer
Contents
BA RRT
ASSISTANT Editor
Kris Williams
41,
Number
2
Classic Reprints
BA
134
Editorial Assistant
Linda Barciis
Volume
Retrospectroscope Redux: Out of the Mouth of
Babes
BBA
/)\
Julius
H
Comroe Jr— Reprinted,
with permission, from the
.American Review of Respiralon Disease 1976:114:1001-1009
Section Editors
R Fluck Jr MS RRT
MS Jastreniski MD
Letters
Robert
Blood Gas Corner
Hugh
142
Phil Kitlredfie— Little River. Califcruia
MD
S Mathevvson
D)»g Capsule
142
D
Richard
Kinreclne
's
A
Scientific Basis for Therapeutic
Wa\t}e
RRT
RRT
Branscni
Robert S Campbell
Editor as Death Dealer
C Anderson — Pitlshnri;h.
Response from Steplumic Hinnes
Touch?
Penn'^ylvania
—.Areata.
Cidifornia
Corner
Correction
Jack
PhD
Charles
G
Wanger
MBA RPFT RRT
lr\ in
1 1 1
Conected
PFT Corner
Palricia
Charles
Test
G
Durbin
JA. Fink JB.
MS RRT
Ann Doorley
MD
Birenbaum
RRT
MD
MD
James M Hurst MD
Robert M Kacmarek PhD RRT
Donald R Elton
RRT
Michael McPeck BS
MD
John Shigeoka MD
id J
Jeffrey
J
155
AARC
86
Abstracts from Other Journals
Advertisers Index & Help Lines
160
160
159
145
148
157
152
144
Ronald B George
Da\
determine
COPD.
0-\yi;en pre-
Respir Care
RRT
Frank E Biondo BS
J
to
In This Issue
Consulting Editors
Robert L Chatburn
Use of pulse oximetn-
1996:41{l):30-36
)'oiir Railioloi;ie Skill
Howard
Lant^hein WE. Skorodin MS. Hultmon CI. Jessen
scription for Inpo.xemic patients with
MD
Jr
abstract
EM.
Haiiartx
Pierson
Ward MEd RRT
Meinbership Application
Author Index
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Respiratory Care
•
February
"96
Vol
41
No
2
85
)
1
Abstracts
Summaries of Peninent
Articles in Other
JoumaU
Commentaries, and Reviews To Note
Editorials,
Community-Acquired Pneumonia— JG
Banleil,
LM
Muiuly.
N
Engl
J
Med
1995:333(24): 1618-
1624.
Pathophysiology of Dyspnea (review)
— HL Manning. RM Schwanzstein. N Engl
Med
J
1995;
333(23):1547-I553.
)
(
mittee on Fetus and
on Obstetric Practice. Pediatrics 1995:96(5, Part
tee
Comparison of Dynamic and Passive Measurements of Respiratory Mechanics
tilated
Keens,
Ven-
in
Newborn Infants — .\ Kugelman, TG
R deLemos, M Durand. Pediatr Piilnionol
—
American Academy of Pediatrics ComNewborn and American College of Obstetricians and Gynecologists Commit-
Perinatal Care at the Threshold of Viability statement
of 2):974-976.
1
term infants were 689f and 649; of
R,„,
equation of the regression line was Re
+ 63 and
20
R,.
=
cm HjO
0.5 R,,
s
L-i,
+
20, with
and
r
SEE
=
and the
0.3 R,^
of 25 and
of 0.65 and 0.69 (p <
0.0001 p < 0,005), respectively. The 2 methods
1995:20:258.
,
are noninvasive
and were well
tolerated.
We con-
0.0 inter-quaitile range, 0.0-0.3
in tlie laboratory.
(
vs 2.4/lir inter-quiirtile range
1
(
ian difference of 2.4/hr (p
med-
.24.2). with a
< 0.001
).
Study dura-
apnea/hypopnea index, desaturation index,
lion,
respiratory and spontaneous movemenl/arousal
and oxygen saturation during sleep were
indices,
home and
Although
and
clude that passive and dynamic respiratory com-
simiUir for
ventilated infants depending on whether they are
pliance and resistance measured in intubated
neither sleep state nor Pco; (transcutaneous or end-
ineasured by a dynamic or passive method. The
infants are highly correlated, although the values
tidal)
measured by the passive technique are higher than
vMiuld have modified patient
those obtained by the dynamic technique.
most,
mechanics may
I'ulnioiiiUA
was
objective of this study
tory
differ in intubated
compare
to
respira-
mechanics measured by a dynamic technique
in
newborn
ventilated
one preterm and 15 tenn
tational age, 29.3
weight,
12±
ied.
1
.2
± 0,5 and
13 and 5
infants
± 2.3 and
3.4
39.5
± 0.4
infants. Thirty-
efficiencies, apnea/h\
uration indices.
weeks:
birth
kg; postnatal age.
were stud-
circuit; tidal
volume by
gration of (low, and airway pressure directly
a pressure transducer. Airway occlusion
the following relaxed exhalation
FM Duchamie, MD Schloss, RT Brouil-
accuracy and practicality of
w ith
atric obstructive sleep
was
per-
inspiration,
and
was analyzed
to
to
home
determine the
sible
OSAS
once
in the
2-
1
apnea syndrome lOSASi
2 yciiis
and referred
at
a cardiorespiratory record-
give passive respiratory system compliance (C^)
sisted of 2 parts:
and resistance (R^). These values were compared
ing of saturation (S^o;), pulse rate, pulse vvave-
with dynamic respiratory system compliance
fonii, electrocardiogram,
( 1 )
popnea
is
and respiratory inductive
Congenital Stridor
—G
CicliiK-ka-Jarosz. Pediatr
Lis,
boy/girl ratio
was
2:1, Fiberoptic
in
without an esophageal balloon and on the same
standard nocturnal polysomnography including
most
common form
larv
Dynamic
electroencephalography was pert'ormed. Expe-
to large,
riences
PEDS and the
home
nificantly
Bicore systems did not differ sig-
and were well correlated. Mean Cjy„
(P) values in preterm and term infants
were 779;
and 779; of C^.: the equation of the regression
C
was Cj^„ = 0.75
- 0.02; and standard
was 0.2 and
coefficient
0.3
(rl
specti\ely. Ttie
86
-I-
0.02 and
C.,y„
= 0.78 Cp,
error of the estimate
mL/cm H;0
(SEE)
with a correlation
of 0.89 and 0.89 Ip < 0.0001
mean
R^.
line
).
(P) \alucs in pretemi
re-
and
w ith another 62
testing alone
reported.
At home,
were also
1
respectively.
home
.69f ,
The
iewed and are
re\
saturation, respiratory,
and 90.0 +
1
7.89?;
sleep efUciency
than in the laboratory. 9
and
± 3.3% (mean ±
video data were obtained 96,4
SD) 99.4 ±
w ho underwent
children
1
.
1
of the time,
was greater at
±
3.99i vs 86.
.
(
1
1.
bronchoscopy
cause of stridor was
of
ngoma-
larv
34 children
(65'-;
).
The
ngomalacia was due
floppy arytenoid cartilages; this was
observ ed Iw ice as often as other forms of laryn-
gomalacia and boys suffered from
more than twice
this abnormiility
as often as girls. Children with
laryngomalacia had significant weight (249;
height 89f
(
)
deficits in
w ith
larv
)
and
comparison with the nor-
mal healthy population (p < 0.001). In
patients
7.29i w ith a mean difference of 5.09} p < 0.0
The median environmentally induced movement/arousal Index was lower in the hcmie than
±
E
was performed w hen other diagnostic methods
had failed to establish the origin of stridor The
which was found
respiratory system
Szczerbinski,
Fifty-two infants and children with stridor were
common
ventilator settings.
T
examined. The median age w as 5 months and the
lacia,
compliance and resistance measured with the
and desat-
Pulmonol 1995:20:220.
most
1
(2)
indices,
adenotonsillar hyperu-ophy.
an 8-hour videotape
obtained with the PED.S ssstem IP) within
plethysmography: and
were suc-
accurate and of practical use
recording of the sleeping child. In the laboratory,
and dsnamic expiratory resistance (R^l
studies
evaluation of OSAS in patients with
hour,
(C,i,„)
all
for pos-
home ;ind
The home test con-
were studied twice, once
sleep laboratory.
home,
testing for pedi-
secondary to adenotonsilktr liypertrophy. Twenty-
one children aged
in, at
using a simplified cardiorespiratory montage plus
in the routine
The objective of this study was
information
We conclude that home testing,
video recording,
Pediatr Pulmonol 1995:20:241.
lette.
inte-
tbrmed with a Neonatal (X'clusion Valve (Bicore
end of
Mograss,
pneumo-
a
tachometer placed between the endotracheal tube
at the
ndrome .Secondary to AdenotonsllHypertrophy— SV Jacob. A Monelli. MA
at
lar
.4
this
management
cessfulh recorded despite a wide range of sleep
,\pnea S)
1
home,
second group of 62 children,
(mean ± SD: ges-
Flows were measured through
pulmonary monitor)
Home Teslin;; for Pediatric Obstructive .Sleep
in the
±
±4 days, respectively)
and the ventilator
case. In the
1
exclusively studied
with those obtained by a single-breath occlusion
technique
was measured
laboratory smdies.
all
but 4
ngomalacia. blood gases were
within normal limits. In 18 children (359}
(stri-
dor was not caused by laryngomalacia. This group
showed
RESPIRATORY Care
significant etiologic heterogeneity.
•
February
"96
vol
41
How-
No
2
5SESS®
.
'
Flow Meter
^
In status
Don't
guess.
bsthmaticus:
NAEP
Adult
Emergency
Guidelines:^
PEFR
Assess.
40-70%
of predicted
vafue after
4
hrs tx in ER.
Rapid
initiation
Consider
successful
hospitalization.
the
and close monitoring of therapy are
ER management of severe
vital to
asthma.' That's
ASSESS' Peak Flow Meter should be a vital part
yoiu-
ai-mamentarium.
ASSESS lets you —
Measure airway obstruction
why
of
easily,
accurately, cost-effectively.
Peak expii-atoiy flow rate (PEFR) provides an objective,
at a fi-action
cUnkally relemnt measui-ement of au-flow
conventional
of
of the cost, bulk, and inconvenience
spirometry.- And when seconds count, you can covmt on
ASSESS to deliver those measurements with superior
—
accui-acy
and
reproducibility.'"''
Evaluate response to therapy and
need
How is
From
for hospitalization.
yom- patient doing? What should you be doing?
initial
presentation thi-ough dischai-ge, the rugged,
—
as
compact ASSESS gives you the haixl data you need
treatment
infoi-med
make
you
help
to
often as you need it
—
decisions in line with
NAEP recommendations.-
Help prevent future acute exacerbations.
come back when their maintenance therapy
and a
Keep it on track with ASSESS
work, or
home,
at
monitoring
regular program of PEFR
Patients don't
—
stays on track.
school
— as a routine part of your discharge orders.
For more information about how ASSESS can help
you deliver better asthma cai-e, call HealfhScan
Products at 1-800-962-1266.
Ai
Peters
REFERENCES'
«(6) 829-849 1992
1
2
Jl
Rossrucker
t>lalional
menlol Asthma Bethesda,
IvID;
J;
Current concepts
in
manaamg
Asthma Education Program- Guidelines
U,S Dept.
of Health
&
J flesfi/a
the Diagnosis snaMan^ge-
status aslhmaticus.
lor
NIH Pub, No, 9 -3042
Hendler JM, Ogiia^ RG c aL An evaluation
Hurrian Services, 1991.
m.
HealthScan Products Inc, 4 Stiapiro
Gardner RM^
and MiniWripht peak flowmeters, ChesI 99(2):35B-362 1991 5
of peak flowmeters at 1,400 m
Craoo RO Jackson BR et al,: Evaluation of accuracy and reproducibility
Products
HealthScan
1993,
5/93
AA710003-0
Cte/ )0i(4): 948-952. 1992.
3 Data on
tile,
the accuracy of Assess
,
©
Circle 119 on reader service card
of
STANDARD RANGE
60
to
880 t/mm
Peak Flow
Meter
LOW RANGE
30
to
Setting the standard
for peak flow monitoring.
390 L/min
—
.
Abstracts
ever, identification of the cause of stiidor in these
patients
important because specific treatment
is
JECTS: Thirteen
healthy, anesthetized mongrel
dogs. Three dogs served as controls and were
can he offered and prognosis depends on the type
immersed but not submerged.
and cause of the anatomical and functional abnor-
submerged
mality present.
i4"
and
Short-Term
of
Ktfects
lerni
l.oiiji-
INTERVENTIONS:
C).
placed
in the
were
Tlie remainder
cold fresh water or cold
in
w ater
salt
DAT.A
agents to permit optimal drug therapy.
SOURCES: Review
ical
and
of the English language clin-
MEDLINE data
scientific literature using
STUDY SELECTION:
search.
Literature refer-
Catheters were
ences were selected through a key word search
femoral artery, right carotid arters
of sedative therapy, drugs used for sedation, and
jugular vein. Electrocardiogram,
•mil light internal
neurologic disonlers and processes to pro-
six'cific
Alhiitfro! Aerosol Thcnip) In Cystic Fibrosis:
pneumogram. and
were mea-
vide an in-depth overview of sedative drug mech-
A
sured continuously during submersion/immer-
anisms of action, effects on neurophysiology and
Report
I'ri'llminary
Barbcro,
.1
Konig.
-I'
Gayer. GJ
[J
Pulmonul
ShalTer. Pediatr
W5;20:2(lri,
I
rectal teniperalures
MEASUREMENTS & MAIN RESULTS:
sion.
Cold water submersion with drow ning produced
of maintenance albuterol aerosol
riic effectiveness
therapy
in cystic fibrosis
(CF) was assessed by
comparing spirometric measurenient.s
ning and end of
begin-
at the
Peak expiratory flow
year.
I
rates
tem-
a large initial decrease in carotid artery
perature (-7.5°
C
in the first 2
mins) compared
C
with immersion).
with a minordecrea.se (-0.8°
No
significant differences
were noted
in the rate
(PF.FR) were measured twice daily to determine
of decrease of temperature between drowning
bronchodilator responsiveness and spontaneous
fresh water
diurnal variation
(SDV). and
were com-
results
pared with groups of normal and asthmatic chil-
CF patients not
and
salt
water.
Dunng
in
cold fresh water
drow ning. aspiration prixiuced gniss hemodilution
«
ith
an average increase
in
body weight of
16.5'i
intracranial
dynamics, phaniiacokinetics. and toxSpecial emphasis
icity profile.
ical
and
was placed on neu-
DATA EXTRACTION:
rologic side effects.
Clin-
was reviewed and data
scientific literature
relevant to neurophysiologic effects of sedative
drug therapy were summarized. Recommendaand of p;ir-
tions for institution of sedative therapy
ticular agents
of
all
cally
were made as a
DATA SYNTHESIS:
pooled data.
patients
ill
w
result of analysis
Criti-
neurologic pathology pre-
ith
receiving regular albuterol
Hematocrit values, serum sodium concentrations,
sent as a unique subset of individuals cared for
therapy served as a control group. In the treatment
and osmolality decreased while serum potassium
in
concentrations, catecholamines, and free hemo-
neurologic patients requires frequent assessment
globin increased. All measured biochemical data
of the neurologic examination, the goal of seda-
dren.
group, forced
ratoiT
\
vital
olume
capacity
second
in the first
nificantly increased
(
(FVCl and
FEV
(
were
)
i
sig-
and 18.4%. respec-
2.2*;^
1
forced expi-
over the course of the treatment year, as
tively)
contrasted with a significant decrease during the
preceding
trol
ye;ir.
During the study
group had a significant decrease
FEFi5.75ri.
PEFR
FEFi.s.vs'j.
the last
FEV| and
significant for
FVC, FEV|.
increased from the
first to
week of the year-long observation period
(from 71.89;
0.01
in
and the difference between treatment
and control groups was
and
CF con-
ye;ir the
to 78.79;
of predicted values, p <
Spontaneous diurnal variations were
).
nificantly greater in the
CF
group of normal children;
nificantly in
study group than a
SDV
decreased sig-
treatment group during the year
tlic
A bronchodilator response of >
of study.
sig-
I
.'i9'f
present in 25.89; of CF patient days, but there
(except PjQ.) remained
during cold
trast,
salt
at
viable levels.
By con-
ti\
an acute care setting. Because monitoring of
e therapy should be to enhance, or to minimally
w ater drowning, average
perturb elicitation of the examination. Neuro-
w ith hemo-
physiologic disturbances introduce distinct risks
body weight increased by only
69;
.
and require
and
conccnlration and a shrinkage of vascular vol-
for sedation
ume. Hematocrit and hemoglobin \akies
in-
understanding before the initiation of any seda-
plasma
their identification
free
tive therapy. Sedative drugs, in particular, act to
hemoglobin values remained unchanged. Senim
disturb central nervous system function and their
sodium concentrations, osmolality, and potas-
effects
sium concentrations increased rapidly
ther neurologic deterioration.
by
creased
cal levels.
but
309'r.
initial
CONCLUSIONS: On
cold water,
all
to criti-
submersion
in
of the experimental animals devel-
oped tachypnea immediately, followed by
ration with predictable elTecls.
aspi-
The biochemical
and pathophysiologic changes
in
cold water
was
drowning approximated those changes reported
was
for
warm
water drowning for both fresh and
salt
exception and continued aspiration
may
result in diagnostic
confusion and
fur-
The pharmacokinetic
common
and neurophysiologic actions of the
classes of sedative agents, such as benzodiaze-
and neuroleptics, as
pines, opioids, barbiturates,
well as ketamine. propofol. ami cloniiline are dis-
Recommendations
cussed.
are presented based
on the specific type of sedation required and the
underlying neurologic disturbance. Several spe-
examples, including head trauma, neuro-
considerable interpatient variability. Frequent bron-
water with
chodilator responders were accurately predicted
of cold water produced extremely rapid core cool -
muscuku' disease, and alcohol withdrawal, are pro-
by their baseline bronchodilator responsiveness,
ing as long as the circulation remained intact. This
\idcd.
hut not by age or personal or family history of
process of acute submersion hypothermia may
neurologic examination
asthma or atopy.
No difference
in
long-term pul-
monary function improvements were noted
between frequent and infret|uenl responders. The
maintenance albuterol aerosol
results suggest that
treatinents reversed the progressive
course
A
in
lung function
double-blind
downward
CF treatment group.
in the
placebo-controlled
study
is
required to confirm these preliminary findings,
saka.
D
M
Katayama.
Bohn. Crit Care
M
Fujita.
Med
H
Orima.
]^)9y.2M
1
G
Barker.
the pathophysiologic
changes occurring during drowning
water and cold
bility.
trolled
salt
water u
ith
DESIGN: Randomized,
SETFING: A
prospective, conin 2
contrasting
laboratory
at a
universitv-afniiated medical institution.
88
\ la-
large
SUB-
menting
sedation
lamines increased exponentially
of
test
the
in
both groups
animals. Clinically, their acute effects on
circulation,
compounded by
significant
ill
Preservation of the
paramount
is
docu-
in
improvement or deterioration
clinical
drowning. Concentrations of circulating catecho-
in
neurologic patient. Phaniiacologic
in this
unique population of acute care
patients requires c;uelul consideration of
under-
tlie
lying neurophysiologic disturbances and potential
ad\ erse effects introduced by sedative drugs.
hypothermia and extreme anoxia, must hamper
the detection of residual circulation
111
at
rescue and
play a role in sudden ilcath from cold
w atci
Quality of Fife Measures before and
after
tack.
Sedation for the Critically
OF
Hanley. Crit Care
III
M
nv
to
Noscwoilhy.
Med
Grace. Crit Care
Med
I la
1445:2.^
(
)BJECTIVE: To
assess
outcome
ted to ;m intensiv e ciirc unit
\
review the scientific basis
sedation of critically
ill
neurologic patients by
lor
sum
mari/ing the distinct neurophysiologic disturin this
the central nervous
I nil
R Johnston. A
I
Shus-
W5:2.3: I65.\
(
ICU
ol patients
).
population and presenting
system effects of sedative
arious quality of
life
ailmission to the ICU.
|iarison
of quality of
admission to the ICU.
RESPIRATORY CARE
•
emphasis on
measures before and
DESIGN:
life
Prospective
before and
1
PATIENTS:
ICU over a
I
after
com-
year after
SETTING: Eleven-bed
medical/surgical ICU.
admitted to the
admit-
using a prospec-
tive l-ye;u' follow-up. with special
OBJECTIVE: To
One Year
an Intensive Care
Nenrologic
(12):2038.
bances present
Admission
L Konopad.
the absence of drowning.
cold fresh
reference to
submersion experiments
cold liquids.
in
CONCLUSIONS:
the critically
Patient— MA Mirski. B Mullclman. )\
2 1:2024.
cific
age, as reported in cases of cold fresh water
towski.
OBJECTIVE: To compare
dam-
protect the brain temporarily from lethal
may
A Canine Study of Cold Water Drownln); in
-WV Conn. K Mi\aFresh >ersos,Sall Water
I
adult
All patients
-year period were
FEBRUARY "% VOL
41
cli-
NO
2
)
Abstracts
were enrolled onl> on
1
first
admission. Patients <
months. At
who died w itiiiii
admission were excluded. INTER-
ing at
7 years of age and those patients
24 hours of
VENTIONS:
lected before
Qualilv of
and 6 and
life
sion.
and hospital
datii
stay;
were
ICU.
ICU admis-
their
and
1
life)
and 12-month
and place of residence
2 months after
ICU
Mean ICU
pital
length of stay
and
iology
(APACHE
tality;
and
1
II)
score
was
14
1
±
7.
.^cute Ph\
Evaluation
it\
p < 0.0
1
year after
very elderly, per-
in the
As
well, the major-
Civ Care Med I995:23(
10): I620-I62I.
timony from the presenters as the basis of
cussions on
tlie
testing
Care Monitoring Devices
ing principles and specific recommendations were
made based on the testimony given. MAIN
RESULTS: The panel detennined the main coi(stituents of the medical dev ice approval process
to
be the Food and Drug Administration (FDA),
the research
and
community, and
clinical
—
between inonitoring and interventional device
devices. Potential alternatives to randomized,
blinded, controlled study designs for device test-
Phv siologic Monitoring Devices. Crit Care
II
1995;23(I0):I756.
Med
ing are: (a) nonblinded, randomized,
one design);
OBJECTIVE: To
management
protocol-driven study; (b) crossover study (n-of-
Cumulative mordevise alternatives to ran-
domized, controlled,
clinical trials that clinicians
and research experts might find acceptable for
patients. Rel-
cat-
document addresses only monitoring
egories. This
Coalition for Crit-
s-
approval of devices used
a decrease in the le\el
the
made
Care Excellence: Consensus Confeience on
and Related Interventions
ical
dis-
and approval process. Guid-
in critical
care medicine.
by care
(c)
design;
(f)
(nmdomized
cluster-randomization
unit); (d)
case-matched contiols;
(e)
mixed
on/off design (before-after); and (g)
historical controls.
CONCLUSIONS: The panel
agreed on the following major recominendations:
FDA
montlis
DATA SOURCES: Tlie Coalition for Critical C;ae
(a) the
Perceiv ed health status increased o\ er
Excellence (Coalition) of the Society of Critical
cific
Care Medicine organized a consensus conference
ucts with the assistance of the Coalition (prior-
and
).
although
tiveness of Critical
3.5%, 6 month 20.6%,
were completed for 293
was
,
I
Standards of Ev idtncc for the Safet> and Effec-
±
5.5
.
ative to baseline, there
(
Health
hospital
age
±7.4 days. Hos-
1
1
sta>
in tlie level
device manufacturers. Distinctions were
month 25% One year quality of life ques-
tionnaires
of acti\
4..^
was 3 ± 4 days,
Chronic
ICU 5.4%.
2
was
DATA SELECTION: The expert panel used tes-
have a decrease
baseline
female and 275 male.
22^)
length of stay
criteria;
cess for testing and appixwa! of monitoring devices,
Patients admitted
)
Weil.
admission. There were
504 patients w ho met the study
20 years (median 54),
at
CONCLUSION:
(89% of patients return home. Sci' ilic rchilal
ccliliirial: Life Measures before and One Year
after Admission to an Intensive Care Unit. MH
of daily living, perceived health, support, and
outlook on
ICU
ity
mortality; quality of life (level of activity, activities
home.
ceived health status increases.
collected: duration of ICL'
hospital. 6-
testimony to a panel of experts regarding the pro-
life, at
262 (89%) patients were
of activity and activities of daih living
ME.ASUREMENTS & MAIN RESULTS:
The following
year,
1
to intensive care tend to
measures were col-
2 months after
1
12
liv-
from family or friends, or outlook on
gible for incliisKin in this study. Repeat admissions
acti\ities
the year for patients
of dail\ living
at 12
> 75 years of age p < 0.0
(
There was no difference
in the level
1
of support
ni
which recognized
critical care
researchers gave
should accelerate publication of spe-
guidances for physiologic monitoring prod-
ities
and content); (b) more multidisciplinary
Are Your Pulse Oximeters and Sensors Functioning?
...How Do You Know.
The
PHANTOM Knows!
The NONIN
FINGER
PHANTOM™
simulates the
r;---
light
^^rpre^'
and
absorption
arterial
blood flow of
the
human
finger.
It is
designed to
test
most pulse
oximeters using
transmittance
type sensors.
//i
Nonin Medical,
Inc.
2605 Fernbrook Lane North, Plymouth, MN 55447-4755
Fax (612) 553-7807
(612) 553-9968
(800) 356-8874
Leaders
in Noninvasiv.
Medical Monitors
J
Circle 99 on reader service card
RESPIRATORY CARE
•
FEBRUARY
"96
VOL
41
NO
2
89
.
.
n
:
1
;
1
y
ii
) j j
\
u
j
aaI
ui
=
it^
i=
d
li
j
iii
^a.. 7^Jir^^
Abstracts ^Poster
Presentations
AARC
The
Education Section
is
and experience
implementing the
lool<ing for educational research
with models and instructional methods that
may be
useful in
recommendations of the Education Consensus Conferences or other issues in
respiratory care education. Special consideration will be given to abstracts and
poster presentations that deal with multiskill curriculum and/or core
curriculum.
The 1996 Summer Forum, scheduled
for July
12-14
In
Naples, FL,
will offer
two opportunities
for
participants to share their scholarly activities with colleagues:
1
Research abstract presentations dealing with respiratory care education. (Paper
will be limited to 15 minutes, including five minutes for discussion,)
presentations
2.
Poster presentations dealing with education models, methods, or materials that can be
shared
for
noncommercial
use. (Individual topics
and presenters
will
be
briefly
introduced: additional time will be allowed for individual review of posters or display
materials and interaction with the presenters.)
Research abstracts and poster presentation proposals must be submitted by April 15, 1996,
for review by the Education Section Review Committee. All abstracts and proposals will be
peer -reviewed, and authors will be notified of decisions by May 15. Questions may be
directed to the review committee chair, Pat Munzer.
«%
Proposals must include three components:
1
Cover sheet that includes the following information:
a.
Type of presentation (research
b.
Title of
c.
Names, primary
name
abstract or poster presentation)
presentation
titles,
of the author
work addresses, and day telephone numbers of the authors: the
will present the paper and receive correspondence should be
who
listed first
e.
A statement of previous presentations or
Two true/false questions with answers
f.
Other information required by funding sources
d.
2.
Camera-ready copy (without author
3.
Camera-ready
publications of the
identification) for
same
or similar
review by the committee
original (with author identification) for possible publication
work
L
L
I I
U L
I
V
V
I
t
It
U lu
L
ill
i;
I
e L
I!
In
H
Abstracts &Poster
PRESENmTIONS
Research Abstracts
abstract double-spaced on plain white paper with one-Inch margins. The abstract should
be written as a single paragraph and linnited to 300 words. The research abstract should Include
Type
the following:
a.
Title of
paper
b.
Brief description of
c.
Brief
d.
Conclusions
work
statement of methodology and findings
Two true/false questions with answers
A maximum of two pages of camera-ready charts and
e.
tables
may be
attached to aid
in
the
selection of the abstract.
Poster Presentations
Type
abstract double-spaced
on
plain white
be written as a single paragraph and
should include the following:
On
paper with one-Inch margins. The abstract should
50 words. The poster presentation abstract
limited to
1
paper
a.
Title of
b.
Brief description of the
c.
Brief
statement of
how
it
was developed and implemented
d.
Brief statement of
how
It
was evaluated
e.
Recommendations
f.
Two
model, method, or material
or judged to be of unique value
for future application
true/false questions with
a separate sheet, describe
how
answers
the information
Each manuscript should be double-checked
for
will
be visually presented
at the conference.
completeness and accuracy before
it is
submitted.
Spell out
terms used
for the first time,
followed by abbreviations
referenced testing (NRT). Thereafter, the term
may be
in
parentheses, e.g., norm-
abbreviated throughout.
Please send the abstract and cover sheet to:
Pat Munzer,
MS, RRT, Program Director
Respiratory Therapy
Washburn
University
700 College
Topeka, KS 66621
(913) 231-1010, ext. 1284
1
I
—
)
Abstracts
research should be incorporated into
studies; (c)
new
commonly accepted clinical
device
may
tools
not need to be tested for clinical utility
—these
accepted tools should be identified by the Coalition;
and
(d) an independent council ot researchers
The
controls ib.Wc).
Score and the American-European Consensus
< 0,01) than the APACHE-matched controls, but
was not statistically higher than predicted mortality (p = 0.416). Both the low-risk and the high-
Conference definition was significantly better than
was
the high-risk group
groups stayed
ICU
3 times as
Lung
the
Although
risk
to serve as consultants to nianulacturers regard-
long as the
ing appropriate study design tor the testing ol
CONCLUSIONS:
devices. See ihe rektleil editorial: Physiologic
icall>
Monitoring Devices. S Alperl. Crir Care Meil
detrimental complications. Although patients
value for
I995:2.U 10): 1626-1627.
requiring "high-risk" interventicms experienced
conclude
>909r
for general medical
patients
Intrahospital transport of crit-
(group
2). the
low frequencv of
in these
safe and carries a
is
low
risk
of
APACHE-matched
Hlnli-Risk Intrahospltal Transport of Critically
controls, the increase in mortality does not appear
and Outcome of the NecJW S/em.
H>do. E Fiscssar) "Road Trip"
cher, S Kapur. J Klemperer. PS Barie. Crit Care
to
Med
patients require a greater length of stay in the sur-
—
U
lWs;:3(l()i:lf>60.
be directly related to the intrahospital transport.
more
ill
patients
is
Intrahospital transport of critically
critically
ICU and ma>
gical
OBJECTIVE;
ICU
Patients requiring trcuisport out of the surgical
are a
ill
group of patients. These
e.sperience an increased mor-
by virtue of the severity of their
tality rate
ICU
.ARDS
racy of
a higher mortality rate than did
Patients: Salet>
definitions maintained an accu-
all 3
control cohorts.
.APACHE-matched
patients
ill
in the surgical
when compared with the
= 0.027 for both comparisons).
Injury Score
definition (p
strict
and clinicians should make themselves available
III
accuracy of the modified Lung Injury
patients, the
overall mortality rate (51.4'7(
significantly higher (p
in
patients
3.49;
(
a low positive-predictive
CONCLUSIONS: We
3 definitions.
all
Lung
that the
pean Consensus Conference definition identify
similar patients, provided that these
diagnoses for
ARDS.
See the
relatcii cdilarial:
Measurements of .Medicine. RC Bone.
Med IW?:2.if 10): 1619 1620.
Multiple
Oruan
Dvsluiiction Score:
Establishing the Relative .\ccuracy of Three
Descriptor of a Complex Clinical
(ICU) patients within the hospital has been asso-
New
JC
ciated with a high rate of potentially detrimental
tre.s.s
complications. This study
mine
was designed
to deter-
the iK'cuiTence rale of transport-related
plications
have any
and
to
detemiine
on
effect
luiit
com-
Definitions of the .Adult Respiratory Dis-
Syndrome
—M
PL Cjoodman, M
L .Ackcrson, PE Parsons. Cril
Heinig, S Barkin,
Med
Care
\Uiss.
patient morbidity
and mortality.
last
few years, new def-
initions of the adult respiratory distress
hundred seventy-five patients were transported
been compared
ICU
operative interventions
for diagnostic testing or
deemed necessary by
surgical or cntical ciu'c team.
& MAIN RESULTS:
Acute Physiology and
Chronic Health Evaluation
APACHE
III
(APACHE)
and
II
scores were determined 24 hours
after admission. Transport patients
were
stratified
and high-risk transport groups.
into low-risk
Patients
their
MEASUREMENTS
were considered a high-risk transport
if
(ARDS) have been
vv
any of the older and poten-
ith
of
tially stricter definitions
ARDS
further stratified into
groups
.^
sented by the
Lung
DESIGN:
ARDS
1
1
1
)
— against a
were then followed during
transport for any potentially detrimental
their
com-
need for an increased dose
plications, such as a
n
=
125).
Intensive care
in a tertiary, university-affil-
tent validity to identify
patients with
lected daily to c\ aluate the performance of these
dysfunction score. Seven systems defined the mul-
ARDS
MEASUREMENTS & MAIN
of hypoxemia, static
and gen-
collected. Tlie
V
ariables indiv idually
tiple
tors
ity
30 published
meeting
were
identified as patients
rence rate of complications was similar
groups (low-risk group.
i.y/r).
The
6..^'7r;
mortality rate for
was
28.6";^.
0,01
)
which was
However,
there
(
10.9';
>
92
by
When compared
with a stricter definition of
ARDS. all
of accuracy
all
higher (p <
conU'ol patients
was no mortality
as a
number of patients.
tive results divided
high-risk group.
renal
tlie total
3 definitions maintained a high degree
in
those patients with a clearly defined
at-risk diagnosis
(group
I
):
Lung
Injury Score
90.0^* (959; confidence interval 84-96);
ified
Lung
Injury Score
97.3';'r
mod-
(959; confidence
Descri(>
valid-
ratio); (b) the
(c)
bilirtibin concentration):
hematologic system
(platelet count);
and
Coma
nervous system (Glasgow
Scale). In Ihe absence of an adequate descriptor
of cardiovascular dvsfunction,
we developed
variable, the pressure-adjusted heart rate,
is
a nevv
w hich
calculated as the product of the heart rate and
the ratio of central
rial
pressure.
venous pressure
to
mean
arte-
These candidate descriptors of organ
dvsfunction were then ev alualed for criterion validitv
(ICU
sig-
Consensus Conference definition 97.39f (959^
ment
from the .AP.ACHF.-nialched
confidence interval 94-100). For these at-risk
of each
was not
interval 94-100).
more than
;md content
system (Po./Fio;
system (serum
(e) the central
From
overall mortality
in
reixirts rev ieu ed.
system (serum creatinine concentration):
and the .American-European
The
of the low -risk group
iiificantlv diflerent
in the 2
defined as the true-positive plus the true-nega-
transport patients
statisticallv
direct result of a transport.
rate
all
than the mortality rate for
(I l,49r).
who
The overall occur-
?>
aggregate as an organ
criteria for construct
(a) the respiratory
(d) the
all
in
could be identified for 5 of these 7 systems:
negative-predictive value, and accuracy of
were detennined. Accuracy was
and
organ dvsfunction syndrome
half of the
access, a need for additional ventilatory support,
did not leave the surgical ICU.
optimal descriptors of organ
dysfunction. Clinical and laboratory data were col-
the hepatic
control cohorts
identified
.ARDS (gniup
medical ICU patients w ith-
P.ATIENTS: ICl!
demographic infonnation were
definitions
= 692)
these studies were evaluated for construct and con-
SETTING:
ratory pressure, radiographic changes,
new
All patients (n
May 1988 and
March 1990. INTERVENTIONS: None. MEASLIREMENTS & MAIN RESULTS: Comput-
sensitivity, specificity, positive-predictive value,
AP-ACHK-matched
PATIENTS:
Surgical
tertiary-level teach-
admitted for > 24 hours between
of vasoactive medications, loss of intravenous
or cardiopulmonary arrest.
SETTING:
ICU) of a
published between 1969 ;uid 1993. Variables from
respiratory system compliance, positive end-expi-
eral
(
stricter
out clearly defined at-risk diagnoses for
2.
ing hospital.
ill-
Systematic literature review;
determine their accuracy.
RESULTS: Measurements
patients
DESIGN:
ness.
MEDLINE
mens required
The
function syndrome as an outcome in critical
organ failure that were
to
and general
an objecfive scale to
the multiple organ dys-
clinical studies of multiple
(gniup
port.
measure the severity of
erized database review of
Prospective.
(ICU) patients
=
1995:
modified Lung
sensus Conference definition
definition of
n
Bernard.
Med
American-European Con-
Injuiy Score, a
Injury Score, and the
based on the number of defined treatment regito maintain the patient during trans-
determine
We
ARDS — as repre-
definitions of
iated citv hospital.
was
to
similar patients are cventuallv identified.
compared new
1 .
Reliable
23(10): 1638.
intensive care unit
unit
.A
NV Chnstou. GR
prospective cohort study.
if
Care
Outcome
Sibbald. Cril Care
lung injury. However, these definitions have never
ciciirh defined at-nsk diagnoses for
high-risk group
WJ
Spnjng.
idenufy patients earlier in their course of acute
> 5 cm HiO.
or a continuous infusion of norepmephrlne. The
syndrome
introduced that potentially
they required positive end-e\pirator\ pressure of
a continuous infusion of dobutainine,
DJ Ctwk.
Miirshall.
CL
OBJECTIVE: To develop
OBJECTIVES: Over the
DESIGN: Prospective, cohort-matched study.
SETTING: A 780-bed urban, university teaching
hospital. PATIENTS: Seven hundred fifty-nine
surgical ICU patients. INTERVENTIONS: One
out of the surgical
Crii
1995;2.3( I0):I629.
these complications
it
methods are
applied to patients with clearly defined at-risk
illness.
often necessary for optimal patient
However, transport of intensive care
care.
mod-
Injury Score, the
Injury Score, and the American-Euro-
Lung
ified
produced
)
mortalitv rate) using the clinical database.
the
first
half of the database (the develop-
set), intervals for the
Respiratory Care
v ;iriable
•
most abnormal value
were constructed on a scale from
February
"96
Vol
41
No
2
v*J
Show
Your Pride
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2
.
Abstracts
to 4 so that a value
ofO represented essentially
mortality rate of <
5%, whereas
a value
mortality rate of > SC^i
.
ting,
work, the fungus Scopidariopsis breviciiidis. hat
autocycled rapidly (> 40 breaths/min)
function Score
(maximum
of 24 1. This score cor-
cx-curred in control tests in
applied on the
ICU
first
mortality
day of ICU
admission as a prognostic indicator and when cal-
ICU stay as an outcome measure.
ICU mortality was -25% at 9 to
culated over the
For the
laller,
points, 507c at 13 to 16 points, 75':i at 17 to
and 100%
points,
showed
score
at levels
of
> 20
0.928
in the
development
in the validation set.
The incremental
in-
crease in scores over the course of the
ICU stay
(calculated as the difference between
maximal
scores and those scores obtained on the
lie.
A
the
day
first
incremental increase
ICU
more
scores accounted lor
in
of the explanatory power than admission severity indices.
CONCLUSIONS:
Tliis multiple
measures of dysfunction
6 organ sys-
in
tems, minors organ dysfunction as the intensivist
it
and correlates strongly with the ultimate
ICU monality and
A
variable.
reflects
ICU
The
hospital mortality.
Multiple Organ flysfunction Score,
organ dysfunction developing during the
stay,
which therefore
is
to therapeutic manipulation.
complementary
sure
w idely available,
potentially
amenable
As an outcome mea-
now
to predictive scores
such a score
may
find use in epi-
demiologic studies of the multiple organ dysfiinction
syndrome. Moreover, an insti-ument
thai
can provide an objecti\ e measure of the severity
of organ dysfunction
sion and
tliat
at
the time of
ICU admis-
can quantify subsequent detenoration
over the course of the
ICU
stay
may prove
an alternative end point for clinical
ful as
involving critically
ill
patients.
use-
trials
See the rckilededi-
Meamremenis of Medicine. RC Bone.
Med IW>::M IOi: 1619-162(1
roriiil:
Care
Crit
the hypothesis that toxic gases
sudden
are a cause of
v\
as
found
in test
grow til. This
taining
papers exposed
result suggests
were due
tions
Davey.
I'hislic
agar medium. See
Hype to
con-
arsenic, or
phosphoms
in
23 pol\ \
To
cot death cases
w ere incubated on
increased leak size, and
decreased with decreased sensitiv
CLUSIONS:
ity setting.
due
ceptible to autocycling
to flow
compensation
lo maintain positive end-expiratory pressure lev-
els in the
ference
presence of an airway leak. The
dif-
maximum
sen-
in autiK-ycling is
sitivity setting of
each
due
to the
\entilator.
and not
to intrinsic
anisms.
growth on the
The 3.3-mL/s
setting
tilator set at 2.5
mL/s
at
been
relea.sed instead at
ings.
The
of Three Flow -Triggered \'entilators
Ciit
—G Bern-
Med
Care
1995;
mL/s autocycled
4 mL/s, due
The ven-
to these find-
maximum setting at
> 10%
readily at leak size of
Since such a leak si/e was present
infants, this selling
mech-
the least prone
the time of this study has
ventilator with the
in
70%- of
should be used with caulion.
L'sing these guidelines, autocycling of
tilators is likely to
23(10): 1 739.
w as
autocycling and seems appropriate.
to
SIDS The-
relaled ediloriiil:
CON-
Flow-triggered ventilators are sus-
the test paper reac-
of sulphur-con-
leak
all
3 ven-
occur mainly in 8%- of infants
with leak size of > 30%. In these cases, lowering
OBJECTIVES: To define
the spectrum of airway
examine the
leak in the neonatal population and
(Kcurrence rate of autocycling of 3 flow-triggered
\'entilators witliin tlie
DESIGN:
defined spectrum of airleak.
and perfonnance of
on a mechanical lung
ulated clinical conditions.
mi.xlel
under sim-
SETTING: An
and research laboratory
sive care nursery
medical center.
versity
inten-
at a uni-
from our intensive care nursery, selected
The
tracheal tube.
due
to a test lung
studied at the
1.2.5.
\
entilators
studied. Ventilators
mode w ith
assist-control
the con-
breaths/min. Each ventilator
trol rate set at
was
of autiKycling of
was subsequently
on the
set
rate
of variable si/e. w bile connected
to airleak
were
at ran-
determine si/e of airleak around the endo-
to
may
may
decrease autocycling,
necessitate reintubalion with a larger endo-
tracheal lube.
was
maximum sensitivity setting, which
and 3.3 mL/s
and also
at
(haracltristics of Objects that Cause
ing in Children
Stool. JS Reilly.
JAMA
-IL
G
Chok-
A Thome Jr. S
D Stool. CL Wilson.
Rimell.
Rider.
1995;274l 22 1:1763.
INTERVENTIONS:
Analysis of pulmonary function tests of 50 infants
dom,
ratory pressure level
or
Prospective study of pulmonary func-
tion tests of intubated infants
ventilators
the sensitivity setting and/or positive end-expi-
for each ventilator, respec-
decreased sensitivity setfings
was varied (10%
10
45%)
OBJECTIVE: To characterize
the types, shapes,
and sizes of objects causing choking or asphyxiation in children
and
to
compare these character-
istics to current standards.
DESIGN: To
evalu-
ate morbidity, retrospective 5-ye;ir niediciil record
suney;
SETconsumer prod-
to evaluate mortality, data reanalysis.
TINGS:
Pediatric hospital and
uct testing laboratory. P.'XTIENTS:
(n
=
165)
body aspiration or ingestion
pital
.All
who underwent endoscopy
at
children
for foreign
Children's Hos-
of Pittsburgh (PA) between 1989 and 1993
and children (n = 449) whose deaths due
to
chok-
tracheal tube adapter/connector sideport and/or
Lancet
compounds used
deatli.
ith
at
of auto-
ventilator flow -sensing or other soflw are
bacterial
GP Heldt,
rapidly
.30%^. In all ventilators, the rate
—
from antimony,
lest this
inyl chloride mattress
mL/s aulocycled
cycling increased w
1
E Knodel.
of > 20%; and the ven-
at leak size
tilator set at 3.3
>
mL/s
1
leak size
at
the ventilator set at 2.5 inL/s autocy-
;
cled rapidly
si/e of
at
man-made objects were recorded by the
Consumer Product Safety Commission (CPSC)
as fire
retardants in col mattresses has been proposed as
a cause of sudden inlant
of > 10%
Reality. Lancet 1995:346:1503.
llie
The ven-
ventilator.
with the inaximum sensitivity set
those without such
.4irway Leak Size in Neonates and Autocycling
stem.
which varies with each
tilator
to aulocy-
sensitivity set-
by increasing the orifice size within the endo-
EM Johnson. C Sieniawska.
Micnobiiil generation of toxic ga-ses
94
tliat
in plates
a function of the
is
Mattresses
199.'S:.346:1516.
until
in
to the generation
compounds during
ory from
More sulphur
infant death.
growth than
taining bacterial
tively,
and Sudden Infant Death Sjndriime DW
Wamock. HT Dches. CK C'ani|vll. I\\ Croudace.
esis,
Our findings
of antimony, arsenic, or phosphorus.
to 10 niL/s. Airieak si/e
(mm
Toxic (Jas (leneralidn
KG
to deposits
organ
dysfunction score, consuucted using simple phys-
risk of
were not due
1
mortality rate. In a logistic regression model, this
sees
instru-
papers showed
Multiple Organ Dysfunction Score) also
demonstrated a strong correlation with the
iologic
that the colour reactions
test
derived from antimony, arsenic, or phosphorus
and
set
Chemical and
plates.
tlie
20
excellent discrimination, as reflected
curve of 0.936
was present on
mental analyses of exposed
do not support
The
points.
rial
which no mamess mate-
1
in areas under the receiver operating characteristic
grow th was present, but these reactions also
rial
when
both
Test
hacilliLs spp.
paper colour changes occurred w henever bacte-
Multiple Organ Dys-
related in a graded fashion with the
rate,
mix of common environmental
a
to yield a
summed
were
maximum
The predominant organism, recovered from all
mattresses tested, was not. as claimed in earlier
each variable
for
tendency of the 3 ventilators
of 4 rep-
These inler\als were
Maximal scores
relative
cle
then tested on the second half of the data set (the
validation set).
papers were
test
then inserted and the colour reactions recorded.
resented marked functional derangement and an
ICU
ver nitrate and mercuric chloride
ICU
normal function and was associated with an
h\ p<ith-
samples Irom
malt agar plates
aood microbial arowth was obtained.
Sil-
ing on
MAIN OUTCOME
the positi\e end-expiralory pressure level (2 to 8
between 1972 and 1992.
cm H:0). MEASUREMENTS & MAIN
RESULTS: In the infants, airieak size was cal-
ME.ASURES:
aerodigestive tracts were characterized by loca-
culated during synchronous ventilator breaths as
tion,
minus expiratory)
(inspiratory
ratory tidal
patient).
15.6
±
1
volume x 100%
Mean ± SD
1%.
A
present in 15
20%
in
(n
24 (48%
),
)
volume/expi-
= 25 +
1
1
breaths/
leak size in the infants
minimal leak
(30%
tidal
si/c of
to
10% was
leak size of
in
20%
4 (8%
and consistency. Three-dimensional objects
that
had caused asphyxiation were analyzed by computer-simulated models.
RESULTS: Of the
165
children treated b\ endoscopy 69%^ were 3 years
7
of age or younger. Foreign bodies most often
inlanls. llie
ingested or aspirated were food (in 36 children)
to
)
procedure for removal, and type. Objects
causing death were characterized by type, shape,
to
infants, leak size of
(14%), and leak size > .30%
was
Objects removed from children's
10%
30%
in
,
RESPIRATORS Care
•
February
"96
Vol 41 No
2
1
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Saturday, December
.\ARC'35-001a
Lung Volume Reduction
Advances
E
Sherry
AARC95-006
AARC95-007
MD.
O Bendill.
RCP
E
InterTntra Hospital Transport
Jet Ventilation
AirTransportof Trauma
I-ochi.
.-I
Jamie
Taylor-!ri:arry.
1.
COPD
AARC95-050
Q
AARC95-05
AARC95-052
AARC95-053
COPD
MD
MD
.AARC95-018
A,\RC95-019
Overcoming the Bamers John IVrighi. MB.-i. RRT
Care Plan Development Jo/m.V i'o/iii. Afi'. flKr
Compiling Objective Data John n right. MB.-t. RRT
What Is ARDS. Who Gets It. and What Happens to Them''
Has Outcome Changed'' Kenneih I' Sieinherg. MD
to
Treatment Siephen
/'
Transformational Leadership .Sum
I
Reniiard.
(;mr<yi7«y,
Q
AARC95-054
O
AARC95-055
D
AARC95-0.S6
p
AARC95-057
Q
AARC95-058
Joshua
New Approaches
Affl.-I,
K/?r
Appropnate Ventilator Management Today'' Seil R
D
MD
A.'VRC95-023
Do
AARC95-024
ARDS'' Kenneih P Slewherg. A/7.)
What Happens to ARDS Survivors'^
,\.'\RC95-027
Sunday, December 3, 1995
What Have We Learned about Lung
,\ARC95-028/29
n
KtD
Barry Make.
Outcomes After Exacerbations of COPD (Support Study)
.Alfred f- Connors Jr. MD
Is
AARC95-049
Victims Jern. 4 foc/». /y?r
Survival Following Severe Exacerbations of
What
Q
RRT
Scientific Basis for Current Tlierapy .SVcp/ira/Z^f/winny A//)
M4clnlyre.
AARC95-048
RRT
AARC95-0I6
AARC95-017
/\ARC95-022
Q
.Mark J Heulill. KfD
Flight Physiology
Natural History of
AARC95-020
AARC95-021
AARC95-047
Couriney. \fn. .MS
on Transport Teams Jerry
Bendill.
n
Affi
Sur\ iving a Joint Venture by Identifying the Crucial Role of
O
AARC95-046a/b
KID
and Expanded Capabilities of Pennatal-Pediatnc
Mechanical Ventilators Mark. I Heiilill. ,MT}
Advances in the Use of High Frequency Osciilalon.
.\AKC9S-Qn
AARC95-0I3
AARC95-014
5
Joshua
Use of High Frequency
in the
Couriney.
A,'\RC95-011
AARC95-01
C Demeni
New Modes
the
AARC95-009
AARC95-0I0
Surger>'
Corticosteroids (or Other Drugs) Alter the Course of
.\'eil
R Madnlyre.
Injurs
MD
from the
Management of Near-Drowning'' Jerome H Modell. KfD
RCPs Meet the Challenge of the NAEPP. Urban Message-(jetting the Message Out and Breaking the Bamers to Care
Thomas I Kallslrom. RRT. .ilvin 1' Thomas. MD
School-Based Asthma Management-Strategies for Asthma
Care for the Child in School & Panel Discussion Mark W
.
.'\ARC95-030
Millard.
AARC95-031
MD
Management of .^cute Respiratory Failure without Intubation
Roherl
Kacmarek PhD. RRT. David J Pierson. MD
Changing the Paradigm The Role of the RCP in Health
Promotion/Disease Prevention William F Galvin. MSEd.
M
AARC95-032
:
RRT.
AARC95-033/34
AARC95-035/36
CPFT
RCPs in the Operating Room. RCPs on the Resuscitation
Team Richard D Branson. RRT Charles G Durhin. Jr
RCPs in the Hyperbaric Chamber. RCPs in the Subacute
Care and Skilled Nursing Facility Setting John
CRTT. Dianne
,'\ARC95-037
I.
Lewis. MS.
M
.
MD
Grayheal.
RRT
Laboratory and Clinical Expenence
in
Liquid Ventilation
Ronald B Hirschl.MD
,\ARC95-038
Practical Considerations in the Therapeutic Administration of
.\ARC95-039
Tracheal Gas Insufflation Sue
\nhd.\tA'ti\XnQO\\Ae Roherl
AARC95-040
Ventilator
Pierson.
AARC95-041
AARC95-044
to
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and coins
Of 449 children uhose
{in 6() children).
deaths after aspirating foreign bodies weie reported
to the
CPSC.
were younger than 3 years. Bal-
fi5'7f
and
months of age. RESULTS: Eight hundred
fifty-
decreased blood pressure compared with the con-
two care givers completed surveys during
the 5-
(+13'*)
levels
cholesterol
lipoprotein
group. In multiple regression analyses, the
trol
improvement
objects such as balloons caused a significantly (p
metabolism was related primarily
< 0.001
higher proportion of deaths
)
3 years or older (6(K<
that
we could
those aged
CONCLUSIONS:
tion in obesity.
suggest
th.it
weight loss
improve coronary artery disease
o\erweighl. middle-aged and older men.
of any age. Changes
in
regu-
Hemorrhage
Intracranial
Neonates Treated
in
use might have prevented up to 14 (M^f) of 101
JN Meliones. EH Kern.
siud\
Sec ihc related editorial:
,
leider.
WJ
DR
— EN Grayck.
RM
Hansell.
Unger-
1
the initial and
max-
imal lactate levels with Ihe occurrence of intracra-
Weight Loss
Kffi'cts of
vs ,\erobic Exercise
Trainins on Risk FactorN for Coronary Disease
in
Healthy, Obese, Middie-.Aged and Older
Men:
Randomized Controlled
.\
Katzel.
ER
Bleecker.
Trial
EG Colman. EM
— LI
Rogiis.
JD
MMA 1945;274(:4l:im5.
Sorkm. .AP Goldberg.
hemonhage (ICH) and
nial
OBJECTIVE: To compare
the effects of weight
on coronary
loss vs aerobic exercise training
artery disease risk factors in healthy sedentary,
DESIGN:
SUBJECTS: A total
obese, middle-aged and older men.
Randomized
controlled
trial.
of 170 obese (body mass index. 30
±
kg/ni-
I
[mean + SEM]). middle-aged and older (61 ±
years)
I
INTERVENTIONS: A 9-month diet-
men.
induced weight loss
inler\ ention.
9-month
aer-
obic exercise training program, and a weight-
MAIN OUTCOME
maintenance control group.
MEASURES: Change
imal aerobic capacity
in
(
body composition, max-
V'o.max). blood pressure,
lipoprotein concentrations, and glucose tolerance.
RESULTS:
to
Forty-four of 73
men
randoinized
weight loss completed the intervention and had
±0.7 kg;
Vo^max. Forty-
a I09f inean reduction in weight (-9.5
p
< 0.001
),
nine of 71
with no change
men randomized
in
to aerobic exercise
completed the intervention, increased
V|),max by a mean of 179f (p<0.fJ01
not
change
completed
DESIGN:
SETTING:
PATIENTS: Eightyfor res-
meconium
piratory failure due to sepsis,
aspira-
or persistent pulmonary hypertension of the
MEASLIREMENTS: The
maximal
lactate level
were described as mean
Head ultrasound
choice of sleep position.
mean
initial
higher
in
1
maximal:
reports
lactate
+ SE
(niM).
and survival were
in
RESULTS: The
patients
who developed ICH
(ini-
mM vs 6.4 ± 0.8 mM, p = 0.05 and
12.4 ± 2.5 mM vs 7.9 ± 0.8 niM. p =
.7
().(W). Initial
elevated
and maximal
nonsurvivors
were also
lactate levels
(initial:
1.7
1
±
3
niM
vs
6.4±0.7niM, p = O.OI and maximal: 14.8 ±3.3
niM vs 7.8 ± 0.8 mM, p < 0.0 1 ). Platelet counts
and
ACT did not differ in patients with and with-
out ICH.
CONCLUSIONS:
Lactate
is
marker for the development of ICH
a useful
in
patients. In addition, elevated lactates during
identify a
CON-
in infant
sleep positioning in the desired direction since the
American Academy of Pediatrics statement. However. 549^ of the study infants
were
being put
still
to sleep prone.
Plasminogen
N
Engl
Med
J
Acute
of Neu-
and Stroke rt-PA Stroke Study
rological Disorders
Group.
for
Institute
Activator
Ischemic Stroke- -The National
1995;333|24): 1581.
subgroup of patients w ith
BACKGROUND: Thrombolytic therapy for acute
ischemic stroke has been approached cautiously
because there were high rates of innacerebral hem-
orrhage
We
in early clinical trials.
randomized, double-blind
performed a
of intravenous
trial
for ischemic stroke alter recent pilot studies sug-
and maximal lactate levels were
ECLS
±
has been a change
pixir
was begun within
METHODS:
The
treatment
3 hours of the onset of stroke.
tnal
had 2
parts. Part
I
(
which
in
291 patients were enrolled) tested whether t-PA
had
clinical activity, as indicated
by an improve-
ment of 4 points over base-line values
in the
score
of the National Institutes of Health stroke scale
(NIHSS) or
the resolution of the neurologic deficit
w ithin 24 hours of
the onset of stroke. Part 2
which 333 patients were enrolled) used
test statistic to
outcome
assess clinical
(
in
a global
months,
at 3
according to scores on the Barthel index, modified
Rankin
NIHSS.
scale,
Glasgow outcome
Results. In part
I,
there
scale,
was no
and
signifi-
cant difference between the group given t-PA and
that
given placebo
in the
percentages of patients
ECLS
with neurologic improvement
ECLS
a benefit
outcome.
when
gested that t-PA was beneficial
months
was observed
for all
at
24 hour^, altliough
for the
t-PA group
4 outcome measures. In p;in
at
3
2, the
long-temi clinical benefit of t-PA predicted by the
results of pari
body composition or Vo;max.
pre-ECLS and ECLS management will decrease
the occurrence of ICH and improve survival.
for a favorable
8
men who
loss decreased fasting glucose
trations
by
insulin
concen-
(OGTT) by S'7t and 26"/^, respectively {p <
By contrast, aerobic exercise did not
0.01).
improve fasting glucose or
insulin concentrations
or glucose responses during the
OGTT
decreased insulin areas by 179r (p < 0.001
In
group (p < 0.05). Similarly, weight loss but
not aerobic exercise increased high-density
Respiratory Care
•
February
'96
30% more
patients
have minimal or no
Pediatrics 1995:96(5):S93.
after the onset of stroke occurred in
least
likely to
on the assessment
patients given t-PA but only
OBJECTIVE:
Tii
dctemiine prev alent infant sleep
American Academy
of Pediatrics position statement of 1992 and to
the con-
confidence
As compared with
tomatic intracerebral hemorrhage
cose and insulin levels and glucose areas with
when compared with
interval. 1.2 to 2.6).
(global odds ratio
1.7; 95'^'(
ability at 3 montlis
—
positions before and after the
aerobic exercise
outcome,
the Pediatric Rese;irch in Office Practices Network.
analysis of variance, the decreinent in fasting glu-
intervention differed between weight loss and
was confirmed
A Community-Based Survey of Infant Sleep
Position
JB Chessare, CE Hunt, C Bourgiiigiioii.
but
).
I
given placebo, patients treated with t-PA were
by 18%. and glucose and
insulin areas during the oral glucose tolerance
trol
w ith
recombinant tissue plasminogen activator (t-PA)
measured through-
times (ACTs) were examined.
1
prone
ECLS
reviewed. Platelet counts and activated clotting
tial:
in tlie
age. Gender, race, family
initial lactate
measured within 6 hours of initiating
out the ECL^S course were collected. Lactate levels
fam-
of the
whether the incorporation of this information into
1
group had no
Weight
test
ECLS
two neonatal patients placed on
:ind the
ft
Prospective studies are needed to determine
whereas the
in the control
2^;^.
and did
Retrospective chart review.
Pediatric intensive care unit.
level
1
support (ECUS).
life
newborn.
4
75'''r
signifi-
their weight,
cant changes in
).
their
survival in patients
treated with extracorporeal
tion,
however,
income, maternal smoking, and birth weight were
Tissue
OBJECTIVES: To correlate
H05.
child,
Greeley. Pediatrics 1995:96 (5):914.
Designing Ihe Death Out of Balloons. SP Baker.
J.\M.\ 1995:2741221.
same
position at the
not associated
Serum Lactate Correlates with
Elevated
with Extracorporeal Life Support
in this
1
CLUSIONS: There
lations regarding products intended for children's
deaths
risk factors
CON-
Balloons pose a high risk of a-sphy-x-
with more than
youngest siblings had been put to sleep
results
in
iation to children
Fifty-four percent of the study infants
to sleep in the prone position. In
These
to
younger than 3 years.
were put
ilies
the preferred treatment
is
week smdy.
to the reduc-
101 objects causing deaths
for use by children
CLUSIONS:
in
younger than 3
lipoproteins
analy/e. 14 met current standards
Of the
years ( 33*^1.
vs those
1
in
glucose
and
loons caused 299r of deaths overall. Confomiing
placebo (p < 0.001
17%
in the
).
Symp-
w ithin 36 hours
6.4% of
0.6% of patients given
Mortality
at
t-PA grt)up and 21%
group (p = 0.30).
scales.
at
dis-
3
months was
in the
CONCLUSIONS:
placebo
Despite an
DESIGN:
increased incidence of symptomatic intracerebral
private and hos-
hemorrhage, treatment with intravenous t-PA
pital-sponsored general pediatric offices. P.AR-
within 3 hours of the onset of ischemic stroke
TICIPANTS:
improved
identify determinants of sleep position.
cross-sectional survey.
Vol
41
No
2
SETTING:
parents of infants younger than 7
clinical
outcome
at
3 months.
97
Editorials
Respiratory Care Education: Current Issues and Future Challenges
The more-essential features of respiratory care education
have remained the same since 1970. Many health-care professions have successfully advanced their educational require-
ments: however, despite the efforts of practitioners and orga-
tomatic of the need for a change
in the
educational system
;ire
comments of graduating students who feel that learning so
much technical material in such a limited time is too demanding. On the other hand, facult> members are frustrated by the
nizations within the field, a three-tiered system persists in the
students" lack of educational foundation in the arts and sci-
respiratory care profession: on-the-job trainees (OJTs), res-
ences that hinders their ability to participate fully
and respiratory
piratory therapy technicians,
nician programs require
1
yeai'
therapists.'
Tech-
of fomial education, while ther-
programs may require 2 years for an associate degree
4 years for a baccalaureate degree.
ing.'"' In
an
Re-Engineering Tool
McCarthy and Kircher
or
to
Although the types of education programs have remained
"Training teaches an employee
stated.*
perform repetitive tasks
A
Respiratory Care Departments"
tV)r
apist
in their learn-
"The Outcome Driven Model:
article entitled,
at
cation provides employees
competent
a
w
ith a
level. Clinical
edu-
know ledge base they can
the field
use in evaluating a situation and making appropriate decisions.
of respiratory care has steadily increased. In 1984, out of a
Recognizing the difference between training and education
unchanged, the
total
number of practitioners entering
of 64,445 credentialed respiratory care practitioners,
total
approximately
35% were
1994, 10 years
later, the total
had nearly doubled
credential.
(1
Registered Therapists (RRTs).
25, 1 52
Also of note,
in
)
By
nuinber of credentials awarded
with 469^ of those being
tine
RRT
1994, 3,870 practitioners gradu-
is
that
cuuent trend appears
50% of graduating students are
for the entry-level
tt)
be
technicians, eligible only
examination for the Certified Respiratory
this difference
is
also a key step in designing an
educational program to prepare respiratory therapists (as
opposed
to training technicians) to participate in the assess-
ment and evaluation of
The
ated from technician programs, while 3,577 graduated from
therapist programs. Therefore, the
a key step in devek)ping a functional outcome-driven m(xlel.'"
Recognizing
ity to
results of
patients.
our study^ designed to assess students"
perform patient assessments suggests
poorly prepared for this function.
ment
vital to the
is
We believe that patient assess-
the remaining
monary
50%
Over
care sites and must be emphasized
10 years,
we have
also seen
more than
number of credentialed puhnonan
in
1984
tt)
8,124
in
the past
a 509^ increase in the
Pulmonary Function Technicians, or RPFT, and
the remain-
der Certified Pulmonary Function Technicians, or CPFT).In
an effort to define the future educational needs of the
of respiratory care, the Board of Directors of the Amer-
field
ican Association for Respiratory Care
steering
committee
(A ARC) appointed
a
organize two Educational Consensus
One of the
Conferences.
was
to
findings of the ensuing Conferences'''
that the future respiratory care
curriculum content would
be heavily influenced b\ the multiple trends
that will
encom-
rehabilitation,
An example
in
response
mendations
ington.*^
is
With
6()9(
sec
modified
its
ECMO), assessment
for a broader
background
written and oral
would require
98
skills,
and care
in alternate
in arts
and sciences
to
communication and analytical
the
minimum
emphasize
skills.
of an associate degree.
This
Symp-
cumculum
of the graduating class of the respiratory
program
to (1
)
expand
ment, age appropnatene.ss of care
and multicompetency
monary function
(ie. [X'diatiics
skills: (2)
skills useful in
first jobs,
skills in patient assess-
and
geriatrics),
increase emphasis on pul-
both the hospital and physi-
cian iilfice; (3) incluiie clinical rotations to subacute, skilled
nursing, and
home
care
sites,
and sleep diagnostics labora-
The curriculum has been expanded
nomic impact of
Consensus Conference conferees delemiined the need
its
AARC
care program choosing alternate care sites for their
increased technical skills (such as cardiiidiagnostics and ther-
the
in alternate
respiratory care edu-
Consensus Conference recom.Spokane Community College (SCO in Wash-
tories.
sites,
in
of a program that has adjusted
to the
pass a wider scope of practice. In addition to suggesting
apeutics and
and care-plan formulation
cation programs.
function technicians (3.639
1994. with 2,707 of these being Registered
abil-
were
success of therapist-dri\en protocols, pul-
Therapy Technician (CRTTi credential, while
are eligible for the Registry examination.
that students
to include the eco-
alternate care sites as well as the required
documentation, legal issues, reiinbursement-billing systems,
and patient care plans.
^'et
tional
another recommendation stemming from the Educa-
Consensus Conferences-^''
as neonatal
is
that specialty areas
and pediatric care, adult
Respirator-!
Care
•
such
critical care, research.
Febru.arv "96 Vol 41
No
2
.
.
Editorials
in post-associ-
and case management might be best studied
therapy and lor the most appropriate delivery method;
ate degree courses.
may
be cogni/aiit of age-related issues and how they impact
respiratory
the patients' ability to understand and utilize various treat-
Restnicturing respiratory therapy education programs
be the answer
to
assess and c\ aluatc their patients regarding indications for
in future
couecting deficiencies
we do to bring our existing body
care practitioners, but what can
of practitioners to the level of present day expectations'
As
one approach. Shrake has suggested the following solutions:"
ment modalities;
adapt hospital policies and procedures to alternate care
domains;
conduct and participate
take ad\ antage of coirespondence or part-time
OJTs should
•
courses offered by U'aditional respiratory schools to enhance
nology;
their basic educational level.
communicate
research activities to assure
in
advances
a scientific basis for
effectively with
all
CRTTs
should consider enrolling
part-time college
in
members of the
body of
care team, and contribute to the
•
respiratory care tech-
in
health-
concern-
literature
ing respiratory care.
courses necessary to qualify for taking the Respiratoiy Care
Registry
Lucy Kester
Exam.
MBA RRT
Education Coordinator
RRTs should
•
choscopy
seek additional 'high-tech"
assisting,
skills,
Section of Respiratory Therapy
such as bron-
hyperbaric medicine, and sleep
medicine, and/or achieve additional degrees
in related
James
areas
such as nursing, education, or management.
States witli licensure laws
ments
time, only 9 states
Pulmonary/Critical Care Medicine
have continuing education require-
that all respiratory care practitioners
must
K Stoller MD
Head, Section of Respiratory Therapy
fulfill.
do not have a licensure law of some
tiiis
Cleveland Clinic Foundation
type.'")
Cleveland. Ohio
(At
Continuing education requirements increase the need for cur-
workers
rently practicing respiratory care
education.
It is
be obtained
seek additional
to
REFERENCES
fortunate that continuing education credits can
in a
number of ways:
(
1
)
continuing education pro-
Wiezalis CP. Toward
1
grams offered by community colleges;
and conferences offered by the
(2) seminars,
AARC.
symposia,
Times 1994;18(1
state affiliates, hospitals,
2.
3.
independent companies; (4) consultant training,
AARC
Buyer's Guide"
lists
companies
ware, audio cassettes, books,
A tool that
we have found
computer
soft-
4.
5.
provide training and to
6.
a
computerized case study program
in
developing
therapist-training
Calvin B, Rinker
RM, Wojciechowski WV.
Meredith RL. Pilbeam SP. Stoller JK.
needs of the future.
9.
and performance-improvement aspects of
10.
Respiratory care education for the future must be expanded
of respiratory care practitioners.
RCPs
and
to
to
meet the changing role
It is
no longer sufficient for
knowledge required
AARC Times
1
994:
1
S(
1
0):
Is
our educational system ade-
1
994,39(1 0):709-71
1.
AARC Times
199,';;19(.S):76-78.
Shrake KL. Strategies for developing the multicompetent respira-
Eicher
J
AARC Times
1994:18(61:21-26.
A. Future challenges for slate hoards for respiratory care.
AARC Times
1
1
Arkell D. White G. Retooling an educational program to meet the
tory care practitioner.
to include the
AARC Times
McC;irthy TP. Kircher C. Tine outconie-dn\ en model: a re-engineenng
protocols? (editorial) RespirCare
8.
facilitate
therapist-driven protocols.
Respiratory care edu-
changing with the evolving health care system.
quately preparing respiratory care practitioners for therapist-driven
which therapists can
This technologic advance will
:
49-.'i4.
review case studies, submit their care plans, and receive a grade
in a single session.
Year 2001 an action agenda. Dallas: Amer-
tool for respiratory care departments.
7.
is
American Association
199.'^;19(3): 17-20.
case studies have been distributed and graded on paper forms
one of our supervisors, Dennis Giles,
delineating the educational direction for the
Proceedings of the second national consensus conference on respi-
cation:
monitor the consistency of therapists' assessments and care
plans for our Respiratory Therapy Consult Service. Although
to date,
:
ican Association for Respiratory Care, 1993.
useful in the Cleveland Clinic
to
Proceedings of a national consensus conference on respiratory care
ratory care education.
and pamphlets.
have used these case studies
NBRC
for Respiratory Care. 1992.
Respiratory Therapy Section has been case study simulations.
We
AARC
a step closer to our future.
:
future respiratory care practitioner. Dallas:
that offer a vari-
ety of educational materials, including videos,
1
Svec LM. Respiratory care credentialing: a growing expeneiice.
education. Year 2001
sponsored by hospitals or respiratory care departments;'' (5)
The
200
Horizons May-June 1993;6-7.
and equipment vendors; (3) videoconfcrences offered by the
AARC and
RCP
):27- 31.
Equipment and
I99.';:19(7):12-14.
supplies: Instructional aid and
The Buyer's Guide,
AARC Times
1
management
support.
994; 8(8):60-62.
1
have knowledge of respiratory therapy treatments
their delivery
methods. Future respiratoiy therapists must
be able to
RESPIRATORY CARE
•
FEBRUARY
'96
VOL 41 NO
2
Reprints: James K Stoller MD. Pulmonary/Critical Care Medicine A-90.
9500 Euclid A\e. Cleveland OH 44195.
99
Original Contributions
Evaluation of a Commercial Standard
for
Teresa
Checking Pulse Oximeter Performance
A Volsko RRT.
Robert L Chalhuni RRT, and Thomas J
Pulse oximeters are unique
amon^
RRT
K;illstroiii
patient monitors in that they cannot be
The purpose of this study «as to
determine whether an inexpensive commercial device simulating a human
calibrated nor can calibration be verified.
finger could produce
measurements of oxygen saturation
(Spo,) within the
METHOD:
error specifications supplied by pulse oximeter manufacturers.
Five brands of pulse oximeters were evaluated.
Phantom
to simulate Spo, values of 80%,
We
used the Nonin Finger
90%, and 97%. Pulse
rate was simand 60 beats/min
as paced b> a metronome. For each saturation level, 8 measurements (different probes) were made at each pulse rate (n = 24). Bias and imprecision
of measurements were evaluated with / and X' tests. Inaccuracy intervals were
ulated by manuallv compressing the device at rates of 120, 84,
constructed to include
RESULTS:
level.
95%
of future
measurements
Simulated saturations showed
bias than manufacturers" specifications. Total
less
at the
99%
confidence
imprecision but
more
measurement error (expressed
as an inaccuracy interval) was within manufacturers" specifications for
cases except for the Novametrix
vidual measurements
may
and the BCl
occasionally
fall
at the
80%
saturation
all
level. Indi-
outside specified values by chance
some saturation levels. CONCT A'SIONS:
Spot checks consisting of single measurements with the Finger Phantom are
probablv adequate for evaluating the performance of all devices studied. Spot
checks using the mean \ alues of repeated measurements could reduce the falsefor
some
well-functioning oximeters at
positive rate. IRcspir Care 1996;4I(2):1()()-I()4|
neous readings, and ease of operation have resulted
Introduction
in favor-
among clinicians.- However, pulse oximeters are unique among noninvasive monitors because there is no way to easily calibrate them, to verify calibration, or to assure accuracy when measurements
able responses to pulse oximetr)
Since
its
introduction
little
more than a decade
ago,' pulse
oximetry has assumed a commanding position among noninvasive monitors in the clinical
from
critical care to
home
care.
management
ol'
patients
Rapid response, instanta-
are questioned.'
Webb et aH summarized
several studies that
attempted to verify the accuracy of pulse oximetry, but,
general, the verification techniques described in the
in
liter-
ature are not practical for bedside application.
Ms VoWiO
is
a supervisor in
is
Respiratory Care Deparlmenl of Si
Mr
Chattiiirri is
Director and
Manager of the Respiratory Care
fX-partiiient.
Rainbow Babies
F.li/abctti's Hospital.
Kallstrom
Itie
& Children's
Youngstoun.
Hospital.
Oliio.
Mr Chalbmn
of Pediatrics. Case Western Reserve
is
Mr
also an instructor in the Fiepartment
The purpose of this study
Hospital. 1044
100
A
that
Belmont
.Ave.
Youngstovvn.
OH 44.S01.
St F.li/abeth's
whether an inex-
human
linger could
were within the error specifications supplied by pulse
I'niversity. Cleveland. Ohio.
Volsko RRT. Respiratory Care Dept.
as to determine
produce measurements of oxyhemoglobin saturation (SpO;)
oximeter manufacturers.
Reprints: Teresa
vv
pensive commercial de\ice simulating a
would be a
We hypothesized that such a device
useful tool for clinicians to evaluate the function
of oximeters and probes used
Respir.ator-* C.-\re •
in the clinical setting.
February
"96
Vol
41
No
2
Standard for Checking Pulse Oximeters
Measurements were repeated w ith different probes, to avoid
any measurement bias due to iiuliv idu.il pix)be characteris-
Methods
The Nonin Finger Phantom* was used to simulate Spo^ values of 807c, 90%, and 97%. Tliis device is comprised of a fluid
tics
mixture with "precisely controlled light absorption characThese
teristics sandwiched between two glass slices""' (Fig.
F.
1
mimic
characteristics allow the unit to
of arterial blood
ities
Each Phantom,
levels.
cial
at
).
light-absorbing qual-
tlie
each of the three specified saturation
prior to use.
was
inserted into a spe-
holder that allowed stable attachment of an oximeter probe.
and
Room
to yield results representative of the type of probe.
temperature was maintained between 70.5° F and 73.5°
According
to the Finger
coiTections of measured
Phantom manual.^ no temperature
coefficient
is 0.
1
6%/° F
F and
is
calibrated
Observed
bias
77.5" F. (Tlie lemix'iatuie
80% Phantom. 0. 3%/° F for
F for the 97% Phantom. Each
for the
1
the 909f Phantom, and 0.07%/°
Phantom
alues are required for ambi-
S;i(), \
ent temperatures lielween 67.5"
72.5° F.)
at
(mean difference between measured and
expected saturation values) and imprecision (standard deviation of differences) of
measurements were compared
ufacuirers" specifications witli
I
-sample
/
test
and X'
Inaccuracy intervals" were calculated
ti\ely.
inaccuracy interval =
A = mean
where
test,
to
man-
respec-
as:
A + kS^
difference between measured and
expected saturation levels; S^ = standard deviation of
differences between measured and expected saturation
levels;
and k = a constant (equal
to 3.017)
allow the inaccuracy intenal to include
measurements
at
the
99%
confidence
chosen to
95%
of future
level.
Values for k depend on the width of the inaccuracy
Fig.
1
.
The Nonin Finger Phantom
sition to
in its
holder with operator
in
po-
val (ie. the percentage of future
in the
simulate a pulse.
size.
For
ufacturers" specifications
Pulsatile blood
pressing the
60
tlat
beats/mill,
How
end of the Phantom
at rates
of
1
20. S4, and
1
to
inter-
be included
inaccuracy estimate), the confidence level desired.
and the sample
was simulated by manually ci)m-
measurements
oximeter brands studied, man-
all
were based on sample
sizes of about
.500, with a corresponding value for k of 2.047. taken
standard
from
All oximeters specified a standard devi-
tables.'' "
paced by a metronome. The Spo, was recorded
ation of 2%- for the satuiations in our study range. Thus, the
con-
observed inaccuracy intervals were graphically compared
to a single 'specified" inaccuracy intcrx al of 2.047 x 2%
only after a steady-state heiul rate
stant to within
had been obtained
(ie.
beat/min of the reference pulse rate for 10
I
seconds) and a good waveform with an amplitude equal {o
= 4%.
three fourths of the scale had been observed.
Results
Five brands of oximeters and six styles of transmittancetype probes were used
in the
study:
Novametrix with Probe-
Type Y, Olimeda with Oxytip Probe. Nellcor with Probe Types
D-25 and 1-20, Nonin with Probe 8000K2. and BCI with Finger Probe 3024.
The oximeters were operated according
to
manufacturers" specifications. All probes were inspected and
found
to
be free of cracks or
tears.
Proper function of each
Table
ified bias
I
slmws
comparing observed with spec-
the data,
and imprecision. Calculated inaccuracy intervals
are illustrated in Figure 2.
specified intervals
by the dotted
(±4%
These
for
all
intervals are
compared
to
oximeter brands) represented
lines.
probe was verified by the absence of system enor codes when
the probe
was connected
to its appropriate
For each oximeter at each saturation
was made with
8 different probes of the
the 3 pulse rates. This resulted in
oximeter
level.
1
Discussion
unit.
measurement
same type
at
each of
24 measurements for each
combination of oximeter bnuid. probe type, and saturation
level.
Each brand of pulse oximeter has
oxygen
saturation.
bration curve
fitted
*SuppIiers of commercial products are listed
tion at the
end of the
in tlie
Product Sources sec-
Respiratory Care
is
The
•
February
"96
Vol
41
No
2
own
empirically
basic procedure for creating a cali-
to record data
from healthy human subjects
with both arterial lines and oximeter sensors. The sub-
jects' arterial
oxygen saturations
are then lowered
ing an isocapnic hypoxic gas mixture.
text.
its
derived calibration algorithm to relate light transmittance to
Once
by breath-
a stable level of
101
Standard for Checking Pulse Oximeters
Table
I.
Summary
Slalislics tor Dilterences
between Measured and True Values
Standard De\lalion (SD) along with Observed and Specified
Mean
ol'
Repeated Measurements: Obser\ed and Manul'aeturers' Specified
Dilference (A).
Observed
Specified
Observed
Specitled
Oximeter/Pri)be
SD
SD
Mean A
Mean A
BCI Finger Probe 3024
1.2
Ohineda Oxytip
Nellcor D-25
Nellcor 1-20
Nonin 8()0()K2
Novanietrix
Y
—
Standard for Checking Pulse Oximeters
cation valid
perspectives. This
when viewed from both
not be true tor error specifications expressed
in the
would
form
""±
and
100% con-
easy to overlook this fact and assume
is
it
fidence, leading to underestimates of the error of the product or process. For example, using limits of agreement with
% of reading."''
Other things to consider in interpreting an error specifi-
our data would yield intervals about
30%
smaller than tho.se
cation include the mathematical limitations of the specification.
calculated for inaccuracy intervals. Inaccuracy intervals serve
only describes a portion of future measurements.
better because they establish limits that include a specified
the validation study yield a stan-
portion of measurements in a population or process, with
such that
it
For example,
from
the data
if
we can
dard deviation of 2%, then
assiiiiic that this
standard deviation represents the standiud deviation of
measurements and
can interpret
between
2%
all
future
below
fall in
the interval
value.
However. gi\cn the assumption
follow a Gaussian
68%
of all
future
to
that
naturally
clusions. In our study, the imprecision of Finger
surements was smaller than manufacturers" specifications,
whereas bias was larger. Looking al imprecision only might
measurement
eiTors
2% error.
If
32%
we
are
of
all
mak-
would like to know the error for a larger portion
To do this, we may simply double the standard
An interv al of 2 standard deviations above and below
of readings.
deviation.
Phantom mea-
will
true
above the
support decisions based on oximeter measurements,
we
comp;uing the obsened and spec-
imptirtant to note that
imprecision (or bias) alone could lead to wrong con-
2%
distribution, this inter\ al represents only
measurements have more than
life
It is
ified
measurements
future measurements. In other words,
ing
a prescribed degree of confidence.
future
all
as the eiTor specification.
it
This means that some portion of
sample
intluence one to conclude that the Finger
ful in all applications.
to
draw
Looking
at bias
the opposite conclusion.
of error was
much more
Phantom was use-
only, might cause one
Combining
the
two sources
revealing and allowed comparison
of inaccuracy intervals.
Tlie specified saturation of each Finger
Phantom was
treated
mathematically as the standard or true value for the purposes
of future mea-
of creating inaccuracy intervals. However, the observed inac-
we continue with the same example, this error
would then be ± 4%. It could be argued that instead of displaying a single number such as 92% saturation, an oxime-
curacy intervals were ultimately compared to the intervals
should really display a message such as "saturation
between 88% and 96%.""
inaccuracy interval
the true value predicts the error for about
surements.
95%
If
ter
Another point
to consider
is
is
our assumption that the sam-
ple standard deviation represents the standard deviation of
all
future measurements. In fact, a sample statistic can only
be a point estimate for the corresponding population parameter
it
and
(ie,
is
known
to
have some uncertainty associated with
repeating the experiment results
in a different
value tor
the statistic). This applies to both bias and imprecision esti-
mates and, hence, to
is
enor
total
specifications. Uncertainty
represented by the confidence level associated with the esti-
mate. The confidence level increases with the sample size.
Most manufacturers use validation-sample
of
1
,000 to
I
,.'iO()
sizes in the range
data points. This allows the user to be
confident that the sample standard deviation applies to
99%
68%
of future measurements or that 2 standard deviations apply
to
95%.*
In contrast,
to
most
clinical validation studies are limited
inuch smaller sample sizes. Thus, error estimates must
be expressed
in a
way
the estimate. For this,
that accounts for the uncertainty of
it
is
interval described in the
interval
is
convenient to use the inaccuracy
Methods
section.
The inaccuracy
similar to the limits of agreement approach
(ie,
derived from the pulse oximeter manufacturers" specifications,
assuming the
ified interval, the
rately
latter to
be
'true."
Thus,
if
an observed
within a given manufacturer" s spec-
fell
Finger Phantom was judged to have accu-
reproduced the manufacturer" s specifications and could
then be used in the field to spot check oximeter accuracy. Spot
checks using single measurements are appropriate
because the inacctiracy interval was created
in this
case
to include a large
percentage of future individual measurements
high con-
at a
fidence level.
If the
observed interval or some portion of
it
falls
outside
the specified interval, then spot checks with the Finger Phan-
tom may
yield false-posifive results
(ie,
falsely indicating an
oximeter-probe combination functioning outside manufacturer"s specifications).
However,
in this
case the
of several measurements might suffice.
Novametrix oximeter with the
Y
A
saturation
when connected
80% satura76-84%
well-functioning oximeter should read
to the
80%
Finger Phantom. But
Figure 2 indicates that an indi\ idual spot
check value might
fall outside of the specified interval (eg, reading
85%
ration), indicating a malfunctioning oximeter even
device
is
value
probe showed an inaccuracy
interval larger than the specified interval at the
tion level.
mean
For example, the
satu-
when
the
functioning properly.
Looking again
at the
inaccuracy interval for this oxime-
we
see that the bias
relatively small.
mean difference ± 2 standard de\'iations) suggested by Bland
and Altman," but it contains more information. Studies of
ter-probe combination,
pulse oximetry and blood gas analyzer performance have
several spot-check values might provide a useful alternative
is
This suggests that a confidence interval for the average of
ably because they are easy to calculate and do not require
index that can be compared to the specified inaccuracy interval. For example, the 99% confidence interval for a mean of
reference to tables. However, limits of agreement are only
5 spot-check values
often used limits of agreement as
point estimates
—no
"confidence"
Respiratory Care
•
summary
is
February
statistics,
prob-
attached to the interval
"96
Vol 41 No
2
would
uration. This interval
is
fall
between -0.7% and 3.6%
sat-
within the specified inaccuracy inter-
103
r
.
Standard for Checking Pulse Oximeters
mean of 5 repeated measurements (perhaps with
so a
val,
5
different probes) could be used to indicate a well-function-
using the
mean
values of repeated measurements could retiuce
the false-positive rate.
ing oximeter.
Two oximeter-probc
and BCI-finger probe)
study demonstrated ques-
in this
Siiturulioii .Staiidurd:
The use of
individual spot-
check values for these devices could lead
to false-positive
tionable inaccuracy intervals.
conclusions
at
the
However, consider
measurements
would lead
lie
PRODUCT SOURCES
combinations (Novametrix-Y probe
80%
some of the
saturation level
above 4V(
to taking a well-functioning
BCI-Fingcr
Ohmeda
machine out of ser-
and
most
(d)
80%
saturation
clinical applications.
is
already
Thus,
accept spot checks as valid for
all
it
in the
may
Ohmeda. A
Wiiukesha \VI
di\
ismn
BOC
iil
Health Care Inc.
CO
Nonin Model 8500ni/8000K2, Nonin Medical
Inc.
Novametrix 700AA', Novametrix Medical Systems
be used and would have adjusted the interval downward
for
Intern.Uional.
CA
Nellcor N2()(l/D-2.s and 1-20. Nellcor Inc. Pleasanton
temperature correction for these two instruments could
slightly,
BCI
.^(124.
37()(l-Oxylip,
Louisville
vice (rather than continuing to use a malfunctioning device),
(c)
MN
Plymouth
Oviineters/ProlK's:
(b) the false-positive conclusion
.
Inc.
time.
expected
that (a) only a small portion of
PuKc Oximeter Tesl System
Finger Ph;iiiloni
Nunin Metlieal
Plymouth
Inc.
MN
Wallingford
CT
danger zone
Statistical
be practical to
the devices studied
Soltuart:
StatView
4..S.
Aliacus Concepts. Berkeley
CA
and
avoid the more rigorous but ciim|ilicated use of confidence
intervals for
Finally,
mean
referp:nces
values.
one needs
to
keep
in iiiiinl the
a confidence intenal and an eiror inters
val
is
disiinclion
al.
between
A confidence
1
inter-
a prediction about the value of a population parame-
ter (eg, the
2.
mean, based on a sample of measurements). Con-
nomial blood gas values or length of slay
An
in
.V
is
4.
inten als
;irc
of interest
when impoitant
on single observations
(eg,
Enor
in c\
more
of
,
and 97% had
measurement error (expressed
for all cases except for the
No\ ametnx and
Recent dcxeiopnienls
J.
II.
m
WB.
Ralston .\C. Runciman
Potential
em in-
pulse oxime-
pulse o\ime-
in
Eftecls of changes in saturation anil signal tjualits
New
for
normal tolerance
York: Marcel Dekker
.Anaesthesia
.
Ma.son RL. Gunst RF. Hess JL.
Statistical
Wiley
less
&
design and anal\sis of exper-
Chatburn RL. Hess D. Research and
tory care. Philadelphia:
10
">
cirk:
Holin
statistics for the clinician. In:
Bakow ED. Comprehensive
WB Saunders Co.
McCarthy K. Decker MJ.
Kacmarck RM. Hess D,
the BC'I at the 80'
New
Sons. 1989:247-248.
Dant/ker DR. Maclntyre NR.
as an
sampling,
limits,
Inc. I9S(1:93.
iments with applications to engineering and science.
ith
inaccuracy inter\al) was within maiuifaclLiivrs" specifications
Kelleher
29-33.
bias than manufacturers" specified val-
cry case. Total
Webb RK.
:
J.
Anesthesiology I992:76((i): lOIS-KUS.
and screening.
,
I987;79
Odeh RE, Owen DB. Tables
9.
impivcisioii hut
infants. Pediatrics
7.
is
8.
staiulaiili/etl saturation levels
newborn
in
Finger Phantom users guide. Plymouth MN: Nonin Medical Inc
Chatbum RL. Mea.surement theory: accuracy issues in monitoring.
In: Levine. Fromm. Critical care monitoring. Chicago: Mosby. I99.S:
.i.
Conclusion
9()'/(
Pulse oximetry: an alternative method for the
J.
6.
lunctioning coirectly by analy/iiig a quality control solution).
Repealed measurements of Nonin Finger Phantoms w
oximetry. .-Vnesthe-
pul.se
I9y|;46(3):2()7-2I2.
changing F|0: based on a pulse
80'/,
M. Peabody
Severinghaus
tiy
decisions ;ue to be ba.sed
oximeter reading or deciding whether a blootl gas machine
ues
Jennis
try.
error interval (in this case, the inaccuracy interval)
Evaluation ol
Jr.
(4):.'i24-528.
an ICU).
a prediction about the \alue of an indi\ idual measurement.
W
New
assessment of oxygenation
fidence intervals are useful for describing group characteristics (eg,
Yelderman M.
siology l983;59(4):349-352.
Strohl
1
KP. Stoller
respira-
995: 236- 273.
1
.IK.
1
Pulse oximetry.
In:
Stoller .IK. Monitoring in lespiralory care.
Chicago: Mosby. 1993:3(19-347.
saturation level. Spot checks consisting of single measure1
ments
v\ith the
uating
llic
104
Finger Phantom are probably adci|iiate for eval-
peilomiancc of
all
devices
in this study.
Spot checks
I
Bland JM. .Mlnian DG.
Statistical
between two methods of
methods
clinical
lor assessing agieenieni
measurement. Lancet
I98(i;l
(S476):307-3IO.
RESPIRATORY CARE
•
FEBRUARY '% VoL
41
No
2
Reviews, Overviews,
& Updates
Tracheal Gas Insufflation:
Adjunct to Conventional Mechanical Ventilation
Sue
A Ravenscraft MD
Introductioii
Methaiiism of Action: TGI
Methods of Catheter (Jas Delivery
Clinical Studies
Technical Aspects
Catheter I'lacenient
Huiniditlcation
Inspired
Oxygen
Effects
Monitoring
Conclusions
capnia"
Introduction
is
the simplest and most widely applied.'^
adjunctive strategies include inhaled
ll is
(ALU
iiKtrc
damage
now known
not homogeneously
thai the
all
alveoli
remain open, and
functional com|iartmcnt receives the entire
and
may be
no
distributed. In severe cases,
is
than one third of
toiind in acute lung injury
tidal
this small
volume
(V-|-)
subjected to overdistension, kx;al hyperventilation,
and inhibition of suifactant.'
of barotrauma
(eg,
In addition to
-
more
typical
tonus
pneumothorax and pneumomediastinum)
animal experiments have shown that transalveolar pressures
that
exceed 30-35
cm HiO
can cause proteinaceous edema
and diffuse alveolar damage
in
previously normal as well as
These observations have stimulated
in injured lungs."-*
est in alternative ventilatory
inter-
techniques that recognize the
importance of alveolar pressure constraints. Among these,
Vps with "permissive hyper-
the technique of using smaller
nitric
gas exchange, and tracheal gas insufflation (TGI).
TGI has the potential to make ventilation with lower
of reducing the
improve ventilatory efficiency have been noted since the 1960s
when tracheostomy, which bypassed the upper airway, was
employed
as a treatment for patients with severe
and ventilatory
failure.'^ -" In 1968,
in anesthetized
normal dogs and
in
MfdiLinc. University of
Minnesota, and
associated with the Section of Pulnionar\ /Critical Care.
St
is
Paul-Ramsey Medical Center.
St Paul. Minnesota.
emphysema
Stresemann demonstrated
humans with
failure that the expiratory flushing of the
respiratory
piDximal dead space
decreased inspired minute ventilation with no change
PaCO-''""
intt)
More
recently,
oxygen has been
insufflated directly
V| by
25%
and dead space by 377f
of transtiacheal oxygen was
found
to
.-'
version of this paper
Annual
New
it
reduce the inspired minute ventilation
has also been
in patients
-''
LIFECARE
Reprints: Sue
640 Jackson
I
with
In the remain-
hypoxemia and chronic airflow obstmction.-"*
der of this discussion. focus on TGI as an adjunctive
tech-
nique to full-support volume or pressure-cycled ventilation.
Horizons Symposium
Orlando, Florida. The
from
was presented by Dr Ravenscraft during Ihc llh
at the )9')5 AARC Annual MeetiiiL! in
The
convenience, cos-
I
A
in
the trachea of s|xintaneously breathing h\'ivrcapnic patients,
metics, and oxygen conservation; however,
Assistant Piiitesscir ol
V ps
more efficient. The benefits
dead space of the mouth and upper airway to
(and, therefore, lower pressures)
initial intent
is
liq-
uid ventilation, extracoiporeal gas exchange, intravenacaval
dcci'easing inspired
Dr Ravenscraft
" Other
oxide, partial
A
Symposium was supported hy an
Ravenscraft
St. St
educational
Mechanism of Action: TGI
iiianl
International Inc.
P.ml
MN
Respiratory Care
•
MD, Pulmonary &
Critical
Care Medicine.
has been
achieved w
.S.^lOlO.Sy.'i.
February
It
"96
Vol
41
No
2
known
for
some time
ithout applying phasic
that ventilation
airway pressure
can be
— by
intio-
105
Tracheal Gas Insufflation
ducing high flows of fresh gas near the carina
in a
valveless
system (constant-tlow ventilation). Stable, elevated
Pco:
t-'iin
be maintained for several hours
in
arterial
apneic dogs
when
ceases in late expiration. During fresh gas flow, an expiratory front develops in this region
lar
between CO^-rich alveo-
gas and CO:-poor fresh catheter gas.
It
has been demon-
very high flows are delivered through catheters positioned
strated in
beyond the
carina.-* If a lung-protective strategy utilizing a
frequency shifts
being employed. PaCO: rises as ventilatory
ing and augmenting the ventilatory effectiveness of TGI.-**
small
Vx
is
effi-
nonnal animals
that vibrating the chest wall at high
this front
mouthward. improving gas mix-
ciency decreases. Because the anatomic dead space remains
relatively constant as
Vj declines,
Vjs
small
are associated
with a high dead-space-to-tidal-volume ratio Vp/Vx). Dur-
60
(
ing ventilation aided by TGI, low-to-moderate continuous or
55
-I
phasic flows of fresh gas are introduced near the carina to
replace a portion of the CO^-laden expiratory gas residing
the anatomic
in
and apparatus dead space proximal (mouthward)
of the catheter
tip.
As
a consequence, less
CO2
is
tidal breath is
improved
(Fig.
50
d
CL
45
S
40
recycled to
the alveoli during the next inspiration, and the ventilatory effi-
ciency of each
g
<
35
).
I
30
2
No TGI
4
TGI
6
10
8
12
16
14
Vcath (tVmin)
End-Expiration
Fig, 2. Effect of
catheter shape. Arterial Pco. plotted as function of
catheter flow
mechanically ventilated normal dogs. The straight
in
TGI catheter (closed
circle) is
approximately
than the inverted catheter (open
circle).
25% more
effective
(Reprinted from Reference
27, with permission.)
Methods of Catheter Gas Delivery
End-Inspiration
Tracheal gas can be deli\ ered throughout the respiratory
cycle (continuous flow or only during a specific portion (pha)
sic
flow) as
shown
in
Figure
3.
Continuous-flow TGI
is
the
simplest to implement and understand, yet has the most potenFig.
1
gas
in
.
Principles of tracheal
the central airways
expiratlon. Ttiis
gas
is
of the next inspiration.
ways
IS
gas
is
insufflation.
With no TGI
CO2
laden with
(left)
the
(black dots) at end-
tial
to
cause the TGI-ass(Klated complications discussed under
Technical Aspects: Monitoring. During
fonn of TGI. the
this
then rebreathed into the alveoli at the onset
With TGI
(right),
the gas
in
the central
replaced with fresh gas during expiration, and less
air-
CO2
is
rebreathed dunng the next inspiration, effectively lowering the
dead space.
catheter delivers a constant flow of gas during both inspiration
it
and expiration. As the catheter flows during inspiration,
contributes to the inspiratory
Wj
decreased a conesponding amount
it
x
[inspiratory tiine (s)
Vt must
catheter flow (L/s)| and the ventilator-delivered
minute ventilation
be
to
is
remain constant.
Although the flushing of the proximal dead space appears
to be the
that
main
effect of
TGI. there
is
adds to a straight TGI catheter's
With
"distal" effect
tilator
ability to
remove CO2.
gas.
a catheter directed at the carina, a jet of fresh gas pro-
jects for a variable distance
beyond
the orifice of the catheter.
extending the Hushed region and causing
ing of gases. This
may
explain
why
tip
even with the
\nm
in the
may
protect the tracheal
distal turbulent
mix-
a straight catheter per-
forms more effecti\ely (approximatels
an in\erted
2.'^'";
)
than one with
orifice placed in the
same
loca-
trachea (Fig. 2).-^ Catheter tip inversion, however,
mucosa
catheter-iinkiced aulo-PEEP.
against jet trauma and reduce
The
In pressure-controlled \entilation. the catheter
another
distal ellect of
TGI may be
As
the catheter deli\ ers gas. the ventilator decreases
inspiratory gas delivery because the catheter's
may
tended overpressurization of the system (Fig.
its
added gas con-
tributes to achie\ing the set pressure (F'ig. 4).
catheter-delivered flow during inspiration
However,
cause unin-
5).
During the
preset inspirator\ lime, the catheter and \entilator are deli\ering
volume simultaneously. When
achieved, the
\
the preset pressure has been
entilator ceases inspiratory
flow and the expi-
ratory valve remains closed until the end of the inspiratory
time.-''
The TGI
limited b> the zone of high resistance to gas transfer that devel-
because
ops just be\()nd the main carina as bulk flow lYom the lung
features,
106
and ven-
function together to simultaneously deli\er inspiratory
is
it
catheter. hov\ever. continues to provide flow
typicall\ not integrated uitli the \entilator's safety
and overpressurization may
Respiratory Care
•
result.
February
Conditions that
'96
Vol
41
No
2
Tracheal Gas Insufflation
02
Continuous TGI
0.1
Phasic TGI
0-1
•
Vcaih
Bypass
'
14
12
10
8
6
4
2
Full Inspiratory
'—
'
1
'
(Umin)
Pressure-control ventilation of normal dogs showing the
Fig. 4.
ventilator-delivered
component
of
tidal
volume
(Vt) decline as
Vt remains
f = 40
breaths/min, set pressure 15 cm H2O. (Reprinted from Reference
catheter flow
(Vcaiti) is
increased and the
total inspired
constant. Ventilator settings: inspiratory time fraction = 0.30,
Partial Inspiratory
Bypass
29, with permission.)
With TGI
Pressure-Control Ventilation
Total Expiratory
Washout
End-Expiratory Washout
Fig. 3.
Flow-time tracings of the various forms of TGI during convolume-cycled ventilation. Tfie shaded areas represent
stant-flow,
the TGI-catheter flow. Continuous
TGI— the
catheter gas flows
throughout inspiration and expiration. Phasic TGI
— the
catheter
gas flows during selected portions of the respiratory cycle. Forms
of phasic TGI include full inspiratory bypass: catheter delivers the
entire inspired Vt; partial inspiratory bypass: catheter and ventilator deliver inspired Vt; total expiratory
Pressure and flow tracing
Fig. 5. Left:
of pressure-control ventila-
an extended inspiratory time allowing equilibration of airway and alveolar pressure (inspiratory flow reaches zero before
the end of the inspiratory period). Right: Addition of continuousflow TGI and overpressurization during inspiration.
tion, with
washout: catheter gas flows
throughout expiration; end-expiratory washout: catheter gas flows
thereby bypassing the anatomic dead space proximal to the
only at end-expiration.
catheter
tip.
In recent
work by Kolobow and
a "reversed jet" catheter has
promote rapid equilibration of airway and alveolar pressure
before the end of the inspiratory period amplify this problem
(ie.
extended inspiratory times, low resistance, and low
res-
piratory-system compliance). This problem can be identified
by examining the airway pressure tracing and can be remedied by placing a pressure relief valve
in line to dissipate insuf-
flated flow that produces excess pressure.'" Setting the ventilator pressure limit just
above the
set
pressure usually pre-
pulmonary ventilation may hold promise, particularly
Phasic inspiratory
TGI can
inspiratory
all
or part of expiration (Fig. 3)." Phasic
TGI can be used
Respiratory Care
•
as the only source of fresh gas.
February
"96
Vol
41
No
2
also be
ventional ventilation (only part of the
Of all
catheter).
bypass
is
the forms of phasic
the least effective," This
in
tilator
is
the
TGI,
partial inspiratory
likely
due
to the fact that
some of the Vj directly near
proximal dead space), when the ven-
simultaneously delivers the other portion of the inspi-
ratory Vt.
with
is
combined with con-
Vj is delivered by
delivering
the carina (bypassing the
TGI
neo-
neonates and children.
and causes variable inspiratory times and alarm actuation.
Phasic
in
and pediatric applications as the only source of fresh
gas in a valved system. This technique termed intratracheal
although the catheter
ration or during
been used successfully
''
natal
vents extreme overpressurization but terminates inspiration
flow can be delivered selectively during inspi-
colleagues,'-
it
still
COi) back
pushes the
common
dead-space gas (laden
into the lunc in front of the
newly delivered
107
Tracheal Gas Insufflation
Vj. Also,
Ibmi of phasic TGI. there
in this
common
is
Both continuous-flow TGI and
no catheter flow
not swept
TGI
CO2.
Second to continuous-flow TGI. phasic expiratory TGI
ume
during expiration, and the
dead space
is
clear of
in
total
expiratory-washout
deli\ered with a straight catheter cause small increases
plethysmographically measured end-expiratory lung vol-
flow-dependent manner. There are three potential
in a
has been the most extensively studied. Total cxpiratow catheter'
mechanisms
flow appears to be as effective as continuous catheter flow"
catheter decreases the cross-sectional area of the trachea,
for this increase in lung volume.-^ First, the
and avoids some of the potential problems generated by the
increasing expiratory resistance. Second,
completely separate gas source continuously flowing into the
tum of
patient.
As long
latory cycle
that the
is
as the end-expiratory portion of the venti-
included
in the catheter-flush period,
it
appears
the discharging jet stream
expirator\' circuit
impedes deflation.
volume of catheter gas delivered during expiration.
tiveness.''*
This means
be effective but
When tracheal
3), the catheter
may
gas
flow
is
ratio ventilation.
still
add
a small
TGI
flow (Fig.
of the end-expiratory
6).
TGI
amount of Vx
to
from the lungs stops
This occurs because,
at the
onset
flow, the gas exiting the catheter
takes the path of least resistance.
Some
sense starting the next inspiration, and
enters the lung, in a
some
limited
human TGI
studies
are available. Stresemann applied
insufflated at end-expiration only (Fig.
may
OnK
TGI may
require a higher catheter flow.
the next inspiration, particularly if flow
before the
Clinical .Studies
even when a short expiratory period
that
employed, such as during inverse
still
some of the momen-
transferred to the alve-
catheter flow through the endotracheal tube and
oli.'^ Finally,
not just the absolute level of catheter flow, determines effec-
is
is
exits through the
open expiratory valve, flushing the proximal dead space.
in 1969.--
The
1
99
1
.
in their P;,c o:
TGI. and both
during catheter
of continuous-flow
TGI
in
flinv.
as part
We
studied the effects
8 patients in respiratory failure and
found a 15-25% improvement
settings (Fig. 7)."
TGI
with multiple chest
in a patient
tubes and a persistent pneumothorax.
in
ventilated patients
Gilbert and colleagues"' used expiratory
of a pressure-limiting strategy
TGI
two
to
patients recei\ed total expiratory
had significant reductions
In
on small groups of patients
TGI
Nakos and
in
Paco:
at
unchanged
\'entilator
colleagues'** reported the use of
7 patients with acute lung injury. With a catheter flow
of 6 L/min. they found a 259f
fall in
Pjco:
at
the
same
inspired
Vj. In a second portion of the experiment, they were able to
Vj by 25% and maintain an equivalent Paco> which
demonstrated the pressure-sparing effects proposed by other
reduce
£
60
-
50
-
q
I
E
40
30
Fig. 6.
Simultaneous tracings
washout
at
for
an animal during end-expiratory
10 L/min catheter flow. Plethysmographic lung volume
volume prior to catheter flow
Superimposed tracings of the flows measured in the inspiratory and expiratory limbs of the external circuit (middle). Proximal
aira/ay pressure (Paw. bottom). Note that lung volume and proximal
airway pressure tracings show pre-mspiratory step changes.
These deflections indicate that gas flows both antegrade (volume
tracing) and retrograde (flow tracing) from the catheter tip during
Baseline
relative to the end-expiratory lung
Distal
6 L/min
(top).
this
108
penod. (Reprinted from Reference 31. with permission.)
Fig. 7. Patients in respiratory failure (n
ing conventional
=
8). IVIean
volume-cycled ventilation
a continuous TGI flow of 6
zontal lines indicate
mean
[(53.1
(SD), Paco2 dur-
±3.1)
torr]
and
at
±2.1) torr]. The dark horivalues. (Repnnted from Reference 37,
Umin
[(45.0
with permission.)
RL.SPIRAr()R> CARI: •
FEBRUARY
"96
VUL
41
NO
2
Tracheal Gas Insufflation
investigators. Recently Belghith el
se\ere
able to etfect a decrease in
to
al'''
studied 6 patients
w
ith
ARDS in the setting of pennissi\e hjpercapnia luid were
84 (26)
torr. v\ ith
mean (SD)
Paco: from 108 (32) ton-
continuous-tlow pure-o\ygen
TGI
of only
= 20/min. inspiratory time = s. continuous catheter
= 6 L/min. Fio; = 0.50 (set on ventilator), the actual Fio:
for the patient would be approximately 0.58. When expiraton' phasic TGI is utilized with pure o\v gen. the effect on Fio;
frequency
is
4 L/min.
1
flow
even smaller.
Monitoring
Technical Aspects
TGI
Catheter Placement
in its
current configuration
makes
routine respiratory
monitoring difficult and. potentially, dangerous. Although
Optimal catheter position appears
few centimeters
to be a
above the carina.* Moving the catheter near the carina causes
a greater "flushable" \olume to lie proximal to the catheter
and ad\ances the turbulent zone generated by the catheter
closer to the lung periphery. Catheters can be placed bron-
TGI appears
or. alternatively,
appropriate catheter insertion
depth can be estimated from a recent chest roentgenogram.
Boussignac and colleagues""-'- have de\eloped an endotracheal nibe with capillaries
tion to deli\ er
TGI
embedded
in the v\alls that
A customized endotracheal tube would
tlow.
remove problems associated
v\'ith
the physical presence of a
catheter passed through the endotracheal tube.
occupies space
in tlie
can func-
endotracheal tube
The
catheter
tine suctioning.
adds another source of gas to the
and does not respond to the usual ventilator safeguards.
Problems arise in both volume and pressure monitoring.
As mentioned
TGI adds to
prev ioush continuous
.
ered inspiratory Vj. In volume-cycled
ume
during inspiration and decreasing the ventilator-deliv-
ered component of the Vj. In pressure-controlled ventilation,
no adjustments need
be made because as inspiratory pres-
to
As described
sure builds the ventilator deliv ers less gas.
there
lier,
is
when long
inspiratory times are used.
causes problems mon-
TGI
Either continuous or expiratory
itoring exhaled volumes. Because gas flows during the expiratory period, it adds to expiratory volume and causes a dis-
to detect a leak.
it
appears that tracheally insuf-
flated gas should be conditioned. Shapiro et aH'
TGI
that
have show n
and the condi-
significantly cools the central airways,
tioned gas delivered by the ventilator can not compensate tor
oxygen administration
this effect. Transtracheal
breathing patients has had serious, rare consequences including
mucus
balls
imd U'acheal
ifying insufflated gas
oped when gas
is
is
granulation.-"-*"
10
cm HjO
may exceed
forced through the catheters
humidifier's leak or burst pressure. -""
1
Heating and humid-
possible, but the high pressures devel-
causes leaks
in
many
A pressure
in
a
excess of
humidifiers.
Oxygen
The
actual fraction of inspired
TGI. especiallv
flated.
When
if
oxygen (FioO
pure oxygen rather than blended gas
continuous insufflation of
with
rise
is
insuf-
100% oxygen
is
Routine monitoring of
pressures (auto-PEEP)
is
the gas continues to flow and a stable pressure
In expiratory
is
with the subsequent Vy. Nomially the gas residing
mon
dead space
at
end-expiration contains about
gen than the inspired gas. The higher the F|o,
tilator,
in the
5%
set
is
delivered
com-
less
oxy-
on the ven-
the less the impact of the catheter delivering pure oxy-
gen. For example. v\ith \entilator settings of
Respiratory Care
•
February
'96
Vj = 600
Vol 41 No
2
niL,
is
never reached.
TGI. an end-inspiratory pause may be added
the catheter
because,
if
from the
ventilator, the
is
obtaining the signal to begin tlow
pause
is
and the gas has not yet begun
considered part of inspirato flow
through the catheter.
end-expiratory pause for an auto-PEEP measurement typ-
cannot be pert'ormed. Another potential danger
con-
is
tinued catheter-gas flow in the setting of an occluded endotracheal tube.
The
inspiratory phase of the ventilator
is
pres-
sure-limited and gas flow ceases, but the catheter gas continues
Vj and
of the anatomic and apparatus dead space gas
With continuous
TGI. neither of these maneuvers can be performed because
to
replaced with fresh gas (during expiration) that
the
and end-expiratory
static (plateau)
also problematic.
to flow to the patient, generating a risk
tion, part
volume.
amount of volume delivered by
employed, the catheter gas delivers a portion of the inspired
raises the actual Fio: of the tnie. deli\ ered Vj. In addi-
set inspired
catheter during the expiratory period.
ically
may
exceed the
the case, then a low-exhaled- Vj alarm can be set that
If this is
An
Effects
ventilators
that actually
takes into account the
tion,
Inspired
Some
exhaled volumes
spontaneously
in
Of even more
pneumotachometer
can be set to alarm at low
is the inability of the expiratory
concern
Although studies are sparse,
ear-
the potential for overpressurization, especially
crepancy between inhaled and exhaled volumes.
Humidification
the deliv-
ventilation, this can
be accounted for by calculating the catheter-delivered vol-
luid. tlierefore, increa.ses
both inspiratory and expiratory resistance and impedes rou-
it
patient
tip
choscopically
to be simple,
of barotrauma. For
TGI
be used safely on a longer-term basis, some simple safeguards need to be added to the system.
TGI markedly
Fig. 8).
distorts the
capnogiaph Uacing (CO: vs time.
Because the catheter
is
continuously delivering fresh
gas during expiration, the end-tidal
zero.
The capnograph probe
of the ventilator, and
location
in
the
v
it
is
CO;
can even approach
typically placed near the Y-piece
gives a
CO;
entilator circuit. If
value reflecting that one
more C02-Iaden gas from
1(J9
,,
Tracheal Gas Insufflation
the periphei7 of the lung
capnogia]">hic
COi
mobihzed during
is
may
\aiue
the actual role of capnography in
monitoring a patient receiving
TGI remains
York: Marcel
Dekker, 1991:433-449.
3.
CO2 removal.'"' Therefore,
New
Adult respiratory distress syndrome.
(editor^)
expiration, the
remain elevated despite improved
Bowlon DL, Kong DL. High
tidal
volume
ventilation produces
Med
increased lung water in oleic acid-injured rabbit lungs. Crit Care
unclear.
1989:17(91:908-911.
4.
Cummings JJ.
Carlton DP.
RG. Poukun FR. Bland RD.
Scheerer
l.ung
overexpansion increases pulmonary microvascular protein perme-
young lambs.
ability in
Patient 7
.S,
jder
Jl.
Adverse
effects of kirge tidal
acid aspiration.
6.
AppI Physiol
J
1990;69(2):.'i77-.sX3.
Corbndge TC, WVxxl LD. Crawford GP. Chudoha MJ. Yanos
Am Rev
volume and low PEEP
Respir Dis 1990:142(21:31
Dreyfuss D, Basset G, Soler P,
Saumon G.
J,
in
S/na-
canine
l-31.'i.
Intermittent positive-pres-
sure hyperventilation with high inflation pressures produces pulmon;iry microvascular injury
Am Rev
in rats.
Respir Dis I9S5;132(4):
X8()-.SS4.
7.
Dreyfuss D. Soler
tidal
Saumon G, High
Basset G.
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pulmonary edema. Respective
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effects of high airway pressure, high
volume, and positive end-expiratory pressure, .Am Rev Respir
Dis 198X;l37(.s):ll.'i9-ll64.
3
4
Time
5
8.
(s)
Fu Z. Costello ML, Tsukimoto K. Prediletto R.
pulmonary
9.
Fig. 8.
in
West JB. High lung volume
Costello O.
Representative superimposed capnograms from a patient
respiratory failure with (lower line)
and without (upper
line)
capillaries, J
6
Am
Rev Respir Dis
Kudoh
I,
1
1
1
987:
Med
2,
Tracheal gas insufflation has potential to improve the man-
also have promise in neonatal ventilation
3,
2 ):3
1
2-3
1
An
dog lungs due
in
to high
volume
in
J.
Increased
peak airway pres-
1
Care
Tsuno K. Prato
in
lungs of nonadult rabbits: effect of ventilation
Med
1990; 18(6 1:6.34-637.
Kolobow
P.
T,
Acute lung injury from mechanical
ventilation at moderately high airway pressures,
where
expenmcntal study.
.S,
Appl Physiol 1984:57(6): 809- 1816,
pattern, Crit
1
3.S(
Peevy KJ, Hernandez LA. Moise .AA. Parker JC, Barotrauma and
microvascular injury
agement of acute lung injury by reducing pressure require-
1
Parker JC. Townsley Ml. Rippe B. Taylor AE. Thigpen
sures. J
1
level of hypercapnia.
Chen
1984:12(.'i):443-446,
microvascular permeability
Cctndusions
the anatomic and apparatus
Funiagalli R. Mascheroni D. Prato P,
Effect of mechanical ventilation on lung water
dogs, Crit Care
TGI may
Appl Physiol 1992;73(1):123-133.
airway pressure during mechanical ventilation.
10,
ments or by limiting the
MP.
T. Moretti
AR. Mathieu-
V. Joris M, Severe impaimient on lung function induced by high peak
L/min continuous TGI flow. (Reprinted from Reference 37, with
permission.)
Kolobow
Elliot
increases stress failure in
.Appl Physiol 1990:
J
69(3):9_«i6-961,
dead space make up a sizable
1
4,
portion of each breath.
Webb HH. Tiemey DF.
Experimental pulmonary edema due to
inter-
mittent positive pressure ventilation with high inflation pressures.
Customized endotracheal tubes may
facilitate the safe appli-
Am Rev Respir Dis
Protection by positive end-expiratory pressure.
cation of TGI.
1974:1 10(.'i):556-565.
Given the cunent possible complications including
damage, overpressurization, and
TGI remains an
tracheal
1
."i.
16,
investigational technique.
Establishing the ultimate clinical
utility
Feihl F. Perret C. Permissive hypercapnia:
we be'
difficult routine monitt)ring.
Am
J
Respir Crit Care
Med
1
994:
1
how permissive should
."^0(6.
Part
I
):
1
722- 737,
1
Kacmarek RM. Hickling KG, Permissive hypercapnia, Respir Care
l993:38(4):373-387,
and safety of TGI
I
requires careful prospective studies performed in
tlie
7.
clin-
ical setting.
Tuxen DV. Permissive hypercapnic
,Am
ventilation.
J
Respir Crit Care
,\1ed l994:l.'iO(3»:870-874.
1
.S,
Brudemian
1.
Alkalay
I.
Stein
M. Frank HA. Tracheostomy
for acute
respiratory failure, Dis Chest 1966:50(4):393-402,
19,
20,
I
thank ."Mcxander B .Vdams
MPH RRT
Cullen JH,
Ann
ACKNOWLEDGMENTS
Int
An
Med
evaluation of tracheotomy
Lyons H. Becker W. Torres G,
emphysema, .Am
lor his assistance
and
critical
2
1
review of the manuscript
Stresemann H.
in
pulmonary emphysema,
l963:.'s8:9.S3-960,
J
Med
Tlie
management
22,
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pulmonary
washout of anatomical dead space
Sattler F. Effect of
on ventilation. pH and blood gas composition
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of severe
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anesthetized dogs.
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Washout of anatomical dead space
Streseniiinn E. Votteri B. Sattler F.
for alveolar hypoventilation: preliminary case report. Respiration
1969;26(6):42.'i-4.34.
fialtiniini L. Pesenli
H. et al.
A. Honihuici M. Bagliimi S. Rivcilta
M.
Riissi
23,
Relationships hetvvcen lung computed loniographic density,
gas exchange, and
PLHP
in
on acute and chronic gas exchange
24,
Drcyluss D. .Saumon G. l.ung inerinllalion: jihysiologic and anatomic
alterations leading to
110
pulmonary edema.
In:
/apol
WM.
Lemaire F
in
humans. ,Am Rev Respir Dis
1989:l4()(4l:S8,s-890.
acute resplratoiv lailure. .'Xnesthcsiol-
ogy mSS;6')(6):824-8.'»2.
Bergofsky EH. Hurewitz AN, Airw ay insufflation: physiologic effects
Couser Jl
Jr.
ventilation.
2^.
Benilitl
J.
M;ike BJ. Transtracheal oxygen decreases inspired minute
Am
Rev Respir Dis 989: 1.W( 3 1:627-631.
Rassulo
1
J,
Celli B,
RESPIRATORY CARE
•
Work
of breathing duriuL' direct
FEBRUARY
"96
tra-
VOL 41 NO
2
—
.
Tracheal Gas Insufflation
O: administration in patients with severe chronic lung disease
(abstract). Am Rev RespirDis 1990;141:A883.
Slutsky AS. Watson J. Leith DE. Brown R. Tracheal insufflation of
sure, flow,
cheal
O^ (TRIO)
at
low flow
36.
A. Ravenscraft SA. Nakos G.
Nahum
Effect of catheter
gas insuftlation
m
How
dogs.
direction
J
Adams AB. Burke WC. Marini
CO: removal dunng tracheal
on
Nahum
WC.
Crooke PS. Marini
JJ.
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ination by an intratracheal catheter.
CO:
elim-
MR.
E.
Miro
AM. Hoffman LA.
39.
Tosata F. Pinsky
Am J Respir Cril Care
40.
Med
Burke
WC, Nahum
Marini
JJ.
A, Ravenscraft SA. Nakos G,
Modes of tracheal gas
Adams AB. Marcy
4
in
JJ,
Bower LK,
Lillehei
43.
is
main-
1994;20:407-413.
Fierobe L, Brunei F, Monchi
M, Mira JP.
Is tracheal
extrapulmonary gas exchangers
gas
in severe
Chest 1995;107(5):1416-1419.
of catheter position, diameter, and flow
rate.
Am Rev
JI,
Med
of
1989;8:47-49.
pressure during endotracheal gas injection.
Shapiro RS. Ravenscraft SA.
J
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Adams AB, Manni
JJ.
Tra-
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GG. Wagshul FA, Henderson D, Kime SW. Fatal airway
(abslract).
Burton
obstruction caused by a
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A, Burke
WC, Adams AB.
45.
mucous
ball
from a transtracheal oxygen
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Solway
J,
1996
Pres-
JH
2nd. Laser resection of
1992;101(1);269-271.
(in press).
Wood LD, Schumacker PT.
Punzal PA. Myers R, Ries AL, Harrell
granulation tissue secondary to transtracheal oxygen catheter. Chest
Tracheal gas insufflation: Catheter effectiveness determined
A, Sznajder
P, Teissere B. Efficiency
endotracheal set up allowing a constant additional gas flow.
catheter. Chest 1991;99(6):I520-I523.
Ravenscraft SA, Shapiro RS,
Nahum
Med
Isabey D. Boussignac G. Harf A. Effect of air entrainment on air-
44.
technique of intratracheal pulmonary ventilation. Pediatr Res
by expiratory tlush \olume.
35,
Kotanidou A. Tsagaris H, Roussos C, Tra-
67(2):771-779.
1993;34(5):6()6-610.
JJ.
clearance
cheal gas insufflation cools and dries gas in the central airways
Muller HE. Kolobow T, Mandava S. Jones M, Vitale G, Apngliano
M, Yamada K. How to ventilate lungs as small as 12.5% of normal;
Manni
new
way
1993;28(3):484-487.
34.
M.
Urgences
CW,
Perlman ND, Kolobow T. Intratracheal pulmonary ventilation and
congenital diaphragmatic hemia: a report of two cases. J Pediatr Surg
new
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Nahum A, Ravenscraft S.A. Nakos G. Burke WC. Adams AB, Marcy
TW, Manni JJ. Tracheal gas insufflation dunng pressure-conU-ol ven-
a
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Wilson JM. Thompson JR. Schnitzer
the
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Boussignac G. Bertrand C. Huguenard
1
Comparison of
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RespirDis 1993;148(3):562-568.
33.
.Adams AB. Nakos G. Marcy
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continuous and phase-specific gas injection
32.
Belghith
tilation. Effect
1995;151:A428.
TW,
S,
insufflation an alternative to
1992;146(4):
Effects of airway insufflation on peak airway pressure during
pressure-control ventilation (abstract).
3L
Nakos G, Zakinthinos
ARDS'
Gowski DT. Delgado
.^.
Tracheal gas insufflation augments
tained constant. Intensive Care
965-973.
30.
JJ.
WC. Nahum
Burke
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cheal gas insufflation reduces the tidal volume while Paco:
Lung mechanics and gas exchange during
pressure-control ventilation in dogs. Augmentation of
and principles of action
Biomed Instrum Technol 1991;
345-351.
TW. Adams AB.
Ravenscraft SA, Marcy
Marini
during mechanical ventilation.
-''8.
A. Burke
Ra\ enscraft
TW.
Eckmann DM. Gavriely N. Intra-airway CO; disunbution during airway insufflation in ventilatory failure. J Appl Physiol 1995;78(2|:
29.
Larsson A, Smith R, Bunegin L. Intermittent-flow expi-
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25(6):45 1-456.
37.
Appl Physiol 1993.75(3 1:1238-1 246.
546-554.
airway models during con-
in
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a preliminary communication.
thesiology 1985;63(3):278-286.
JJ.
Gilben
J
ratory ventilation (IFEV): delivery technique
Anes-
rates sustains life for several hours.
and density relationships
stant-flow ventilation.
46.
Adams AB.
Tracheal gas insufflation. RespirCare 1996:41(4) (in press).
CORRECTION
In the abstract
of the paper by Hagarty
Fink JB. Use of pulse oximetry to
Respir Care 1996:41
( I
EM. Langbein WE.
Skoro(Jin
(ietemiine oxygen prescription
for
MS. Hultman
hypoxemic
CI. Jessen
patients with
J A.
COPD.
):30-36. the first sentence in the Results section should reati:
Average SpO: during the
last
30 seconds of WALK'""
ing the lift-push-carry, undress and
dress,
(WALK "') was significantly lower than dur-
and ascending and descending
stairs.
We regret the error.
RESPIRATORY CARE
•
FEBRUARY
"96
VOL 41 NO
2
111
I
Cardiorespiratory
Barbara Wilson
Interactions
Foreword:
ihis issue.
III
ture
Rl.SlMRAT()K^ CarI' iiilii)duccs a
—committed
to teaching
among
relationships
A New Teaciiino
new
the cardiac and respiratory systems, car-
diopulmonary disease, and the practice of respiratory
Any
care.
abnomiality that inteniipts the delicate balance between
these
two organ systems, be
it
disease or treatment, can cause
aca.scade of worsening pathophysiology and undesirable clin-
outcomes. Moreover, alterations
ical
one system can cause
fore,
we
alterations in the
in the
performance of
second system. There-
should consider these systems as one
—
the car-
diorespiratory system.
RRl'.
km
Melioncs ML),
Feature for RESPIRATORY CARE
All facets ol adult, pediatric, and neonatal i"espiratt)ry care
fea-
and reintbicing the physiologic
MEd
and John Palmisano RRT, Section Editors
may
are potential sources for submissions. Cases
from any setting
—
nostic laboratories;
to
CRI should
and rehahilitation/liome
ctire.
Submissions
follow publication guidelines for RESPlR.vroRY
CaRI; and include a case study w
tions,
originate
general, subacute, and critical care; diag-
ith ilhistiations. figures,
equa-
and a glossary of terms.
We hope you read and enjt)y the introductory articles and
We welcome your questions and comments and
case study.
invite
you
to contiibute
from
interactions
your
own examples
of ciudiorespiratory
\oiir practice of respiratory care to
CRI.
Cardiorespiratory interactions (CRI) are the physiologic
interplay
sy.stem.
Barbara
between the components of the cardiorespiratory
These interactions affect the delivery and
of oxygen and the elimination of carbon dioxide. Other such
may
interactions
(;
Wilson
Pediatric Critical Care
&
Respiratory Care Services
be related to the administration of cardio.|(»ii
therapeutic agents, resulting in untoward respiratory events
(eg, j8 -blocker therapy
of CRI
is
and bronchospasm).
An
understanding
therapeutic interventions are considered and undertaken
to
improve oxygen delivery and eliminate carbon dioxide.
anticipate and then
measure
Meliones
&
MD
Anesthesia
Medical Director of Pediatric Respiratory Care
essential for respiratory care practitioners (RCPs).
RCPs must
N
Associate Professor of Pediatrics
As
MEd RRT
Research Associate
utilization
Division Chief. F\'diatric Critical Care
Duke Children's
Duke
the physiologic
Hospital
University Medical Center
Durham. North Carolina
responses to interventions, and alter the care plan based on
patient response.
We introduce "CardiorespiiatoiN
of three articles,'
March. The
'
first article is
Research Associate
a review of cardiovascular anatomy
Department of Pediatrics
and physiology.' The second
in this issue
ailicle builds
The
third presents a
and a
on the
cusses specific cardiorespiratory interactions
care.-
M Palmisano MA RK
John
Inteiaclions" in a series
third in
two presented
first
in
and
CSMott
dis-
Unix
respiratory
ersil\
Children's Hospital
of Michigan Medical Center
Ann
review of echocardiography as an
.'\rbi)r.
Michiaan
approach to evaluating CRI and respiratoi^ care inteiAentions.'
The March
in a series
Issue of
in the clinical
As
RESPIRATORS Care
of case studies to
also presents the
illustrate the
importance
i>f
first
management of patients.
Irani
with our other teaching features, each submission must
have a central focus.
ture, that
focus
Gas Corner."
is
In the
"Test
Your Radiologic
the radiograph or
the focus
is
CT
REFERENCES
CRI
Skill"" fea-
scan. In the "Blood
on the blood gas analysis and
inter-
CA. Korn IH. Melioncs JN.
L'ndcisiandinii cardiorespiratory
interactions: c;irdiovascularanaloin\
and ph\sioloi;\ |rc\ieu
I.
Rcspir
Care I996:4I12):M.V122.
Black DR. Wilson BG. Meliones JN. The role of cardiorespiratory
interactions in respiratory care (review). Rcspir Care 199fi;4l(2):
123-132.
pretation. In
CRI, the focus
action, luid the case
trate the
112
is
on the cardiorespiratory
and other supporting material serve
importance of
thai interaction.
inter-
to illus-
Bengur
A\<. Melioncs JN. NcSniith
echocardiography
Care
in the practice
J.
Kappelcr M. Li
J.
The
role of
of respiratory care (review). Respir
19')(i:4l(3):iii press.
Respira
lOR'i
Care
•
February
'9(1
Vol
41
No
2
Understanding Cardiorespiratory Interactions:
Anatomy and
Cardiovascnlar
A Tram MD,
bv Charles
Frank
1
1
Fhysiolog)'
Kern MD, and Jon
N
Meliones
MD
Introduction
Cardiac Anatomy & Physiology
Cardiac Klcctropliysiology
Autonomic Nervous System
Hemodynamics
Myocardial Performance
Muscular Contraction-p]xcitation Coupling
Myocardial Membrane Receptors
Regulation of Myocardial Contractility
In Conclusion
Introduction
An
iai-
understanding of basic pulmonary and cardiuvascu-
piiysiology
is
essential for full
comprehension of the
inter-
actions that occur between these ingan systems. In this review,
we
present cardiovascular
anatomy and physiology and
the
basic theories of hemodynamics and myocardial peiformance.
Cardiac Anatomy
The human
atria
and 2
heart
is
ventiicles.'
word meaning
'
a
&
Physiology
4-chambered organ consisting of 2
The term atrium
a central
room
(in a
ing recessed walls and multiple openings.
term meaning small belly and
cles" structural
ically
nonnal
is
derived from a Latin
is
Roman
'
house) contain-
Ventricle
resemblance to the stomach.'
heart, systemic
a Greek
is
used because of the ventriIn the
venous blood returns
anatom-
to the right
side of the heart and drains into the right atrium (Fig.
riizhl
atrium (RA)
is
a thin-walled
chamber
1
that receives
).
The
blood
Dr Trant was Senior Feliou in Pediatric Cardiology when tliis paper was
written. He is now in private practice in Florence. South Carolina. Drs
Kern and Meliones are with the Departments of Anesthesia. Pediatrics,
and Respiratory Care. Duke Children's Hospital, Duke University
Medical Center, Durham. North Caiolina.
Fig. 1. Normal blood pressures and oxygen saturation (circled)
data with arrows indicating flow of blood, RA = right atrium; RV =
nght ventncle; LA - left atnum; LV = left ventricle; PA = pulmonary
artery;
Reprints: Jon
Duke
N
Meliones
MD. Duke
Universitv Medical Center.
Respiratory Care
•
Children's Hospital.
Durham NC 277
February
"96
PO Box
cava;
AO ^ aorta; SVC = superior vena cava; IVC = inferior vena
M = inean blood pressure. Adapted from References 4 and
5, with
U).
Vol 41 No
.^046.
2
permission.
n3
Cardiorespiratory Interactions
three large veins: ihe superior
I'lDin
vena cava (SVC), which
aortic arch.
The tenu
drains the head and upper extremities, the inferior vena cava
may have come from
(IVC), which drains the lower body, and the coronary sinus,
donian knife sheath
which
The oxyhemoglobin
carries myocardial blood.
ration in systemic
satu-
venous blood ranges from 35-55% for blood
returning from the coronary sinus to
65-75%
for blood return-
ing from the
IVC and SVC. Nomial IVC and SVC mean
sures aie 2-5
mm Hg. Venous return from the right atrium then
pres-
passes through a .3-leafcd \alve, the tricuspid valve, before
entering the right ventricle (RV).
The anatomic arrangement
of the valve leaflets prevents backward flow of blood during
The volume of blood ejected during
the total volume in the ventricle during
ventricular contraction.
compared
systole
diastole
tion fraction is
RV
The
to
A nomial ejec-
referred to as the ejection fraction.*
is
is
in the chest cavity).
The
pri-
RV
by the
RV
and the RV is only required
low pressures. The systolic pressure generated
a low-pressure circuit,
is
is
usually on the order of 20-25
mm Hg. Because
pressures are higher than atrial pressures, the
a greater muscle
ditions of
mass than
pulmonary
the
RV
has
RA. Under pathologic con-
ailei^ hypertension or pulnioniu"y steno-
sis the
muscle mass of the
reduce
RV
RV
increases in an attempt to
RV
pulmonary system
enters the
through the pulmonary valve (a 3-cusped valve). The pulartery
arteries.
the usual site of
is
sampling for mixed-venous
blood when cardiac output and oxygen consumption measurements are made. Normal mixed-venous oxyhemoglobin
saturation obtained from the
main branches
pulmonary
artery
fonning an extensive capillary network
exchange of carbon dioxide
tlie
the circulating blood
(saturation 999r
)
is
65-75% and
iuid
in the
lungs that
oxygen between
to enter the left atrium (L,-\).
left
it
left
ven-
a low-pressure structure that supplies blood to the
ventricle across the mitral \al\e during diastole.
is
a bicuspid valve (2-leafed) and
The cone-shaped
lell
a high-pressure \entricle.
mm
adult.
rise to the right subleft
common
subclavian artery. The aorta then
left
and becomes the descend-
'tail')
ing thoracic aorta.
Cardiac Elect rophysiology
The cardiac
electrical .system consists of .specialized
cle tissue that rapidly conducts electrical impulses
right atrium to the
and ventricular
ulus
is
Hg
apex of the ventricles
contraction.''
The
"
to
synchronize
atrial
origin of the electncal stim-
a bundle of specialized muscle cells called the sinoatrial
(S,A) node.
The SA node
is
the
pacemaker of the
RA near the junction of the
located in the
SVC.
is
at the
junc-
and ventricular septa provides the only nor-
tion of the atrial
electrical
heart and
A second ntxJe
of tissue, the atrioventricular (AV) node, located
mal
mus-
from the
connection between the
atria
and ventncles. The
AV node delays the signal from the SA node allowing the atria
tiation
els
fill
the
\
entricles. prior to the ini-
of \ enuicular conuaction. The elecuical signal then \id\-
from the
electrical
AV
node through the Bundle of His. where the
system bifurcates into the right and
left
bundle
branches. These branches provide a pathway for electrical
impulses that depolarize and open channels in the
brane, initiating muscular contraction
of the
that
in the
cell
mem-
respective ven-
Ventricular contraction occurs from the apex of the
he;irt.
wave of contraction continuing up
to the base
TTius, a coordinated \entricular contraction occurs
maximizes
the
amount of blood ejected
into the aorta.
ventricle
(LV)
u hich
The
mitral
\
ulated
&
is
3).
modulated b\ the autonomic
MycK'ardial pert'omiance
by two separate and opposing systems:
is
reg-
the sympathetic
ever, during conditions o( stress (eg. fear, exercise, sepsis),
(PNS). Under nomial conditions, the
I'*'").
130-150
The volume of blood ejected by
across the 3-cusped aortic
Cardiovascular function
ner\()us system'^ (Figs. 2
ejects blood into the
The
LV
is
creates systolic pressures rang-
in the infant to
.Autonomic Nervous System
nervous system (SNS) and parasympathetic nervous system
so
high-pressure systemic arterial system (Fig.
normal
which gives
named because
is
resembles the hat (mitre) of a bishop."'
ing from 50
transverse aorta has three
The LA, a rect-
angular structure situated directly behind the right and
valve
left
and the lungs. Fully oxygenated blood
then returns to the he;ul through the four large
pulmon;u7 veins
tricles, is
The
carotid arteries, the
turns caudally (towards the
ventricle with the
for
common
carotid artery, and the
tricles."
s
ascending aorta.'
blood to the head and upper exuem-
the innominate artery,
clavian and right
mm Hg. The pulmonary artery branches numerous times, evenallow
Mace-
to describe a
like the
aorta then continues cephalad (towards
that supply
normal pulmonarv artery pressures range from 20-25/10-12
tually
The
the head) and turns leftv\ard.
ities:
much
curved
adequate time to empty and
wall stress.
Blood ejected by the
monary
that
recorded by Aristotle and
first
word used
vessels that arise from the aorta are the right and
first
coronary
a crescent-shaped structure located directly
mary function of the RV is to pump blood through the pulmonary system. Under normal conditions the pulmonary cirto generate
was
a Greek
75-80%.
beneath the sternum (anterior
cuit
The
aorta
mm
the
Hg
in the
LV flows
al\c into the ascending aorta and
PNS
predominates.
the predominant system that stimulates the
SNS. The mycx-ardium
and
left stellate
is
ganglia
myocardium
Howis
the
directh innervated through the right
— SNS nerves
(Fig.
2).''
These neu-
rons cause the release of a neurotransmitter, norepinephrine,
lesulting in
;ui
increase in hc;ul rale and in the force of mycK-ar-
dial contraction.
SNS
stimulation of the adrenal glands prompts
the release of epinephrine into the vascular system. Elevated
*See Glossarv following the References section.
114
levels of epinephrine further stimulate an increase in heart rate
RESPIRATOR"*'
Care
•
February
"96
Vol
41
No
2
Cardiorespiratory Interactions
and the force of contraction. This response has been refened
to as the "tlght-or-night" response, hi contrast, stimulation of
the
PNS.
acting primaiily through the vagus nerve, causes the
which has an inhibitory
release of acetylcholine,
effect
on
myocardial performance and causes a decrease in the heart
rate and a mild decrease in the force of myocardial contraction (Fis.
The PNS. in contrast, tends to decrease systemic vasculai' resistance. The balance between the SNS and PNS helps maintain
appropriate oxygen delivery to the tissues. Abnormalities in
cither the
PNS may
Humoral mechanisms
3).'*
have physiologic sequelae, such
PNS stimulation)
SNS stimulation).
(eg. the renin-angiotensin
system)
also responsible lor regulating lulerial pressure luid intravasrelease renin in response to hypoten-
The kidneys
culiu- \ Illume.
"Stress"
sion and renal hypoperfusion. Renin then triggers the con-
Emotions,
i Anticipated
O
or
or tachycardia and hypertension (excessive
iu-e
;
SNS
as bradycardia and hypotensit)n (excessive
version of angiotensinogen to angiotensin
II
—a
reaction that
Exercise
occurs, primarily, in the lungs. Angiotensin
II is
a potent vaso-
constrictor that produces a substantial increase in ailerial presLeft Stellate
sure by increasing systemic vascuku' resistance." '"Angiotensin
Ganglion
n also causes the release of aldosterone from the adrenal
Aldosterone
is
a
hormone
that
Inotropic
State
and water and an increase
I
mate
gland.
causes the retention of sodium
in intravascular \
result of renin-angiotensin stimulation
olume. The
is
ulti-
an increase
in
./J1:
ventricular
\olume and increased
Role in
Arrhythmias
Hemodvnaniics
Sympathetic innervation of the heart. Stress leaiJs to activation of the sympathetic nervous system, acting mainly through (1)
the right stellate ganglion to release norepinephrine (NE) to areas
Hemodynamics
Fig. 2.
of the sinus
(SA) and atrioventricular (AV) nodes,
ganglion to stimulate the
to release
left
epinephrine (E)
From Reference
ceptors.
Q
^
and
ventricle,
into the
8, with
(3)
(2) left stellate
the adrenal glands
blood stream.
= beta-1
|3^
arterial pressure.
re-
is
the study of blood in motion. In gen-
eral, factors that affect the
motion of blood include blood flow
(Q). the change in pressure across the vascular system (AP),
and the resistance (R)
sure,
to
How. Ohni"s law
relates flow, pres-
and resistance by
permission.
Vagal Nucleus
lOthNen/e
Alteration of the diameter (or radius) or length of the vessel
by the autonomic nervous system and changes
in the vis-
cosity of the bkKxl aftect the resistance to blood flow. Poiseuille
A
O
(1846) described resistance as
Nicotinic
Receptors
o
Reduceid
Diastolic
Atropine
/'
A
ACh
Gil
'
AV
/
Ttr"
where 8
(Modest)
Proteins
Cyclic
lar
)
AMP
Changing
a constant, and ;r= 3.1416.
the length of the blood vessel or the viscosity
(hematocrit) of the blood aftects resistance. However, because
i
R
of the heart.
The
mam
direct innervation of the sinus (SA)
and
atrioventricu-
(AV) nodes and
lease.
is
j
Parasympathetic innervation
(1
by
Rate
K- Channel
Fig. 3.
tube
Negative Inotropic Effect
Receptors
action are
(r)
Blocli
i
Muscarinic
x: G
and radius
rj).
Aihlele's Heart
j
Inhibition
(/.)
(
Heart
Depolarization
SA Node
Competitive
/-^
length
relates to viscosity
it
(2) prejunctional inhibition of
ACh = acetylcholine. From Reference
sites of
norepinephrine
8. with
re-
permission.
is
proportional to the fourth
power of the
radius of the ves-
sel, even small changes in vessel diameter (2r) can dramatically alter resistance. Vascular resistance opposes the forward
flow of blood. The primary
cardiovascular system are
sites
of vascular resistance
in the
and precapillary
level.*
at the aiteriokir
Muscular arterioles and precapillary sphincters are under autonomic control. Vascular resistance is expressed as the mean
The nervous system can also influence vascular tone by
altering vascular smooth muscle contraction and relaxation.
Stimulation of the
lar resistance
SNS
causes an elevated systemic vascu-
bv reducina the diameter of the blood vessel.
Respiratory Care
•
February
'96
Vol
41
No
2
pressure drop across a capillaiy bed divided by the blood flow
(Ohm's Law)."
'-
Pulmonary vascular resistance
tance across the pulmonary-capillary bed and
is
is
the resis-
determined
by measuring the mean pulmonaiy-ailerN' and mean
left-atrial
115
—
Cardiorespiratory Interactions
pressures. Noniially
tliis is
a very low-resistiince system because
of intrinsic properties of the lung (Fig.
the systemic circulation in
).'"
1
Contrast this with
which there are many
different cap-
beds with different metabolic needs. Vascular resistance
illar'
of the systemic circulation
detemiincd by measuring the
is
mean
ference between the
and mean
aortic
dif-
right-atrial pres-
sures divided by the
amount of flow through
To ensure adequate
perfusion of each capillary bed. the sys-
the vasculature.
and flow ceases. Later
the
P wave),
occurs (after
in diastole, atrial contraction
pressure again exceeds \entricuku pressure,
atrial
and blood flows from the atrium to the ventricle (a wave).
systole begins (beginning of the
sure exceeds
QRS
pressure imd the atrio\ enuicuhu'
atrial
\
early phase of systole. Ncntricular pressure
is
pressure but not higher
Duiing
iulenal pressure.
—no
higher than
isovolumetric contraction
sure system. Vascular resistance, both systemic ;md pulmoniu"y,
the aortic valve
can be manipulated by
closed aortic and mitral valves causes an increase in
asodilating or
\
asoconstricting drugs.
Myocardial Performance
(c
wave).
When
The coordination of the electrical and mechanical events
in the myocardium were first described by Wig-
atrial pres-
atrioventricular valve
ventricular pressure exceeds aortic pressure,
the aortic valve opens,
occurring
ejection of blood occurs because
closed. Ventricular contraction against the
is
upward displacement of the
sure due to
atrial
phase
tliis
temic circulation must be both a high-flow and a high-pres-
v
alve closes
blood into the atrium. During the
to prevent regurgitation of
tli;ui
When
wa\e) \entricular pres-
and
\
entricular ejection occurs.
Muscular Contraction-Excitation Coupling
gers in 1916.'^ Figure 4 illustrates the relationship between
the electrocardiograph signal and pressure and
volume changes
and great vessels during a typical cycle. The P
in the heart
wave corresponds
to atrial depolarization, the
tricular depolarization,
T wave
and the
QRS
to ven-
to ventricular repo-
larization or recovery. Atrial repolarization also occurs, but
the evidence
hidden
is
QRS.
in the
cell membnine CiJled
composed of long myotlbers
Muscle cells or myocytes have a special
the sarcolemma.'"^
witli
Myocytes
are
each myofiber composed of myofibrils. There aie two kinds
—
of myofibrils that aie interdigitated to form the myofiber
and thin filaments
thick
Thick filaments are primarily made
(Fig. 5 A).
up of a protein called myosin, a large molecule ending
in a
composed of actin and
reg-
myosin head. Thin filaments are
ulatory proteins. During cardiac muscle contraction, the elecElectrocardiogram
trical
stimulation of the
membrane
to
smcolemma causes
open and allow the
Tlie influx of calcium leads to the release of
in llie
sarcoplasmic reticulum.'
ion channels in the
influx of sodium
'^
Calcium binds
the configuration of the regulatory proteins
and calcium."'
more calcium
on
to ;uid
stored
chimges
the thin filaments
I
facilitating the
E
E
5B). This binding changes the contlguration of the myosin head
binding of the myosin head to actin'"
so that the head flexes, thus
rils
past each other
moving the myosin and
-'
(Fig.
actin fib-
and shoilening the myocyte.-"-' Energy,
a.
in tlie
Systole
Tliis
Diastole
fomi of adenosine uiphosphate. binds
the actin filament, and prepares the
Fig.
4.
Electrocardiogram and pressure tracings obtained from
catheters
in
the
left
ventricle
and
left
The cardiac
atrium.
cycle
traction cycle.-"-'
Ventricular
to left atrial
filling
occurs
in
two phases
pressure being tiigher than
wave) and active
filling
during
atrial
left
— passive
filling
due
ventricular pressure (v
contraction (a wave).
from the
aortic diastolic pressure, the at)rtic valve closes.
During the next phase of diastole, ventricuku' pressure continues
to
fall
but vcntiicular
volume
is
m;untained. This phase
When
to as isoN'olumetric relaxation.
falls
below
(mitral
atrial
iti
atrial
the
is
\
is
the \entricle
higher than
\
refeired
tills
\
myocyte
for another con-
end of contraction, calcium
is
removed
special
pumps
in the cell
membrane.' '- Tlie regu-
sites,
and the relaxation phase
cover the actin
begins.'''-' Relaxation
an active process and can consume up to 159^ of the total
energy of the hean.-^
ation
may be due
Some ha\e
postulated that part of relax-
to a recoil effect.-^ In the intact heart, end-
contraction
volume may be
similar to a
compressed spring, the muscle springs back
less than equilibrium
beginning of relaxation to create a suction
ments early \cnlricular
volume. So.
at
like effect that
the
aug-
filling.
Myocardial Membrane Receptors
passi\eh' because
entricular pressure. In the mid-
dle pha.se of diastole, atrial and
the
entricular pressure
pressure (v wave), the atrioventricular valve
LV) opens and
pressure
the
.-Xt
latory prtucins then alter their configuration to
is
below the
myosin head.
both by active uptake by the sarcoplasmic retic-
cell
ulum and by
binding
The contraction of the myocardium can be di\ ided into tw o
main phases, systole and diastole. During eariy diastole, the
ventricle relaxes and \entricular pressure falls. As LV pressure
falls
tlie
is
divided into systole (ventricular ejection) and diastole (ventricular
filling).
to
causes a confomiational change to the myosin head, releases
entricular pressures equalize
For many years, intravenous beta-adrenergic-receptor
(^AR)-agonist agents, including dopamine, dohulaminc. and
RESPIR.VrORV C.^RE • FEBRUARY
% VOL 41
No
2
.
Cardiorespiratory Interactions
A
plasmic second-messenger molecules (Fig.
Z Line
stimulation of /iARs in the
ZLine
10
Myosin
nm
activation of
G protein (Gs) that, in tum. activates adenyl cyclase
to increase generation of the second messenger. cAMP (Fig.
stimulatory
Actin
Actin
For example,
6).
myocardium causes
7).
Cyclic
AMP acti\ates protein kinases in the sarcoplasm.
which then phosphorylate
and calcium channels)
tractility.
When
myosin ATPase,
target structures (ie,
cause increased myocardial con-
to
receptor stimulation persists, a second regu-
latory feedback process
known
as desensitization leads to
blunted responsixeness and a decrease
in
receptor number.-'"--'"
Desensitization processes can take on various forms and 3
microanatomy showing (A) the arrangement of the
myosin and actin myofibrils during contraction and (B) the interaction of the myosin head with the actin molecules and the action of
calcium (Ca**) on the regulatory proteins on the actin filament. The
region between 2 Z lines is a sarcomere, the functional unit of the
myocyte. SI and S2 are subfragments 1 and 2 of the myosin
Fig. 5. Myofibril
of these processes ha\
/3AR
e
been recently described
acti\ ation results in
—prolonged
cAMP generation
diminished
for
a given stimulus (uncoupling), disappearance of receptors from
the cell surface through sequestration, and decreased receptor production.
'"-"
molecule. From Reference 23, with permission.
epinephrine ha\e been the inainstay of treatment for patients
with low cardiac output syndrome. These agents act by stimulating
membrane
receptors,
celluku' cyclic adenosine
in intracellular
calcium and
which function
cAMP results
initiates
to increase intra-
monophosphate (cAMP). The increase
in
an increase
in intracellular
myocardial contraction. Agents
Cell
in
1
Second Messenger
Membrane
increase myocardial contractility (positive inotropes) act
through various mechanisms that ultimately result
GDP
GTP
that
an
increased intracellular calcium concentration and stimulation
of excitation-contraction coupling. Recent ad\ances
ular biology techniques
in
molec-
mechanisms by which inotropic agents exert
Because of the advances in knowledge about
the molecular
their effects.
Physiologic Effects
have allowed research into many of
Fig. 6.
through a specific
the signal transmission
U'actility
pathways influencing myocardial con-
afforded by these techniques,
levels of circulating catecholamines can
and
result in a
it
now
is
clear that high
ha\e a paradoxic
reduced inotropic response
effect
in selected patients.
In particular, patients with chronic congestive heart failure,
exposed
to
binding to
membrane
membrane
effector, activates
a cytoplasmic sec-
ond messenger. An example is the Gs, or G stimulatory, protein,
which, in the presence of GTP (guanosine tnphosphate), activates
adenyl cyclase, a membrane-effector molecule that generates
cyclic AMP. Cyclic AMP activates protein kinases and increases
calcium concentrations necessary
intracellular
traction coupling.
patients
— Drug,
G-protein-coupled receptor
receptors, activates guanine nucleotide regulatory proteins, which,
GDP
for excitation
con-
= guanosine diphosphate.
cardiopulmonary bypass, and neonates
represent groups of patients with high levels of circulating
catecholamines and reduced responses to exogenous catecholamines. Recent findings have increased our understanding
of the molecular mechanisms for this response and ha\ e not
Alpha-
1
adrenergic receptors a(
of receptors present
1
in
AR provides a mcxlest inouopic effect,
receptors are linked via
but. in
some
cases, have revealed fertile
new
tigation that ha\'e therapeutic potential.-''
Of the many
found
in the
areas of inves-
-'*
the majority belong
to the G-protein-coupled-receptor family
.-'*-'"
This group of
receptors mediates several important signal pathways involved
with cardiovascular homeostasis
(ie.
SNS- and PNS-medi-
ated adrenergic and muscarinic cholinergic receptor systems).
Activated
G protein-coupled receptors are
nucleotide regulatory proteins (G
linked via guanine
proteins) to specific mein-
brane effectors that are responsible for the generation of cyto-
Respiratory Care
•
February
'96
Vol
AR
Gq
results in the hydrolysis
41
No
phate (IP3).
it
receptor phys-
appears that these
7).
Stimulation of
of membrane
phospholipids,
(DAG) and
The liberated IP3 and
kinases and mobilize calcium
Stimulation of a-
1
proteins (Fig.
with liberation of diacylglycerol
types of excitable transmembrane proteins
sarcolemma of myocytes,
a-1
are another group
a- AR's
not completely understood, but
iology
poor inotropic response to /3AR-agonisi agents
is
AR)
human myocardium.
only supplemented previously existing explanations for the
in these patients
1
in a
inositol triphos-
DAG then activate protein
similar fashion to
resulting in a positive inotropic effect.
As
is
cAMP,
evident from the
previous discussion, the sairolemma plays a pivotal role
in the
signal convergence required tor mytx';udial conU'action because
several different receptor systems influence the generation of
each inotropic second messenger
/3AR-agonist agents
rine)
(ie.
at this site (Fig. 6).
dopamine, dobutamine. epineph-
mediate the most potent inotropic effects in
adults.-"
How-
117
Cardiurhspiratory Interactions
doses of /?AR-agonist agents, '-These drugs result
* *
myocardial
pijHp
VIFl 5Hll
R
PGE1
ss
a^
ET *ng
agonists.
\
cAMP.
from
III
inhibit-
in the
cyto-
intracellular
calcium concentration remains high, and
is
enhanced. Through these mechelicit
important phys-
iologic responses in the absence or presence of intravenous
PIP2
j^^^
increased
Phosphodiesterase
anisms, phosphodiesterase inhibitors
DAG
in
different
enzyme phosphodiesterase
myocardial contractility
cAMP
is
plasm of the myocyte. By augmenting the length of action of
I
ATP-.lsnr-^
that
cAMP breakdown by
inhibitors decrease the rate of
ing the action of the
I
by a mechanism
employed by /3AR
that
II
cinitractilil)
/JAR-agonist agents.
+IP3
u.sed
When
phosphodiesterase inhibitors are
alone they increase the inotropic state of the myocartlium
by augmenting the efTicacy of circulating endogenous cateFig. 7.
The 12-surface G-protein-coupled
{|i^. /J2),
receptors- Beta
tiistamine 2 (H2). vasoactive intestinal peptide (VIP), 5
hydroxy tryptophane (5HT), and Prostaglandin El (PGE1)
vate the
and 2
1
Gs
G
or
stimulatory protein and increase
G
inhibitory protein that inhibits
cAMP. Alpha
reducing cytosol levels of
and angiotensin
(Ang
II
II)
all acti-
through
M1 and somatostatin (SS)
stimulation of adenyl cyclase. A1,
activate the Gi or
cAMP
((x^),
1
and
is
inositol
similar to
membrane
Gq
activates protein kinases
it
from enhanced effects of the exoge-
contractilits also results
nous /3AR-agonist agents. '-
all
protein,
to
augment
ical is the
contractility, are
of
IP3 and
DAG
and mo-
angiotensin-li receptors,
of angiotensin
example,
in
I!
varies
possible that a
more potent combination of recep-
it
tor s)
stem and cardiotonic agents exists for the treatment of
is
low cardiac output using other membrane receptors. For example, there are
1
2
known membrane
receptors on myocytes that
possess inotropic propeilies. Howe\er.
membrane
we
tiugel only the
/JAR-
Still
However,
among
(Table
the inotropic poten-
Alternative approaches to inotropic
support ha\ e been limited because available drugs are not
highly selective and. therefore,
effects, In\esiigation into
more
may have untoward
Table
1,
Comparison of
the Relative Inotropic Potency of G-Protein-
Coupled Receptors
/5-2 .Agonists,
Receptor
durin;;
Maximal
Stiriuilation with /J-1
and
systemic
selective forms of these agents
holds great promise for the future, spccificallv
/JAR dow n-regulation.
Regulation of Myocardial Contractility
1).
theoret-
patient populations. For
receptor pharmacologically to augment inotropic
state
more
neonates. angiotensin-II receptors are expressed
at lO-fold the adult level."
e\er.
.
which ha\e only 3{)-509f the inotropic
potential of /JARs in adults.
tial
bilizes calcium.
underway
therapeutic potential of such receptor systems as
produce diacylglycerol (DAG)
cAMP
way
in
Clinical trials of thyroxin, a nonconventional inotropic
The combination
the
phosphodiesterase inhibitors aie used
intravenous j3AR-agonist agents, improved
agent that works by several noncatecholamine mechanisms
triphosphate (IP3).
in
ith
endothelin (ET),
receptors activate the
lipids to
When
conjunction w
adenyl cyclase,
which activates the second messenger, phospholipase C, which
then hydrolyzes
cholamines.
in patients
with
Cardiorespiratory Interactions
ume.
In the intact heart, the stretch
is
Increased Penpheral
proportional to the vol-
Resistance
ume
of \ enous return delivered to the \entricle during dias-
tole.
An
increase in venous return results in a greater
volume
of blood in the ventricle, more ventricular stretch, and an
increase in preload (Fig.
An
8).
increase in preload leads to
CO.
provided the ventri-
precise
measurement of ven-
an increase in stroke volume and
cle
is
not "oxer stretched"."
The
tricular preload requires quantitation
which
is difficult
return
is
of ventricular-fiber
to measure. Therefore, the
6
6
stretch,
volume of venous
Unchanged
Venous
6
used to approximate preload and can he measured
during cardiac catheterization or by echocardiography. In most
Return
6
intensive-care situations, end-diastolic ventricular pressure
is
measured
to estimate end-diastolic \entricular volume.'*'
f=^
6
Exercise
•
6
Volume Expansion
—^
Increased
d
Venous
"N
Return
Unctianged
^^
\^-
LV Pressure
Stroke
Volume
(and Cardiac
Output)
Preload
Eventual
Fig.
9.
LVH
Increased afterload (increased peripheral resistance)
leads to increased blood pressure but not to decreased cardiac
output unless the resistance exceeds the maximal capacity of the
ventricle.
Mechano-
LVH
= left-ventricular hypertrophy.
From Reference
23.
with permission.
Receptor
Because blood pressure
is
the product of the
CO.
and sys-
Heart
temic vascular resistance (Ohm's law), any increase
Rale
in vas-
cular resistance causes an increase in both blood pressure and
Starling's
Law
wall stress. Stroke
volume does not usually decrease when
afterload increases, unless the afterload
in a fall in ventricular
Increased preload (increased end-diastolic volunne or
Fig. 8.
23,
witfi
decreases the force opposing ejection and causes an increase
in stroke
volume and CO..
resistance to ventricular shortening, or afterload,
on the pressure gradient
that the ventricle
depends
must overcome
generate blood tlow (Fig. 9).'^ In the intact heart, afterload
the ventricular wall stress that
as long as preload
and heart
rate
do not change.
permission.
Contractility
The
excessive and results
in-
creased venous return) leads to increased volume loading of the
ventricle, increased stroke volume, and increased cardiac output.
From Reference
is
performance.'" A decrease in afterload
was described by Laplace
to
is
as
erties
is
a
term used to describe the
intrinsic prop-
of muscle not related to preload or afterload
state.'-''"
As long
as heart rate, preload,
change, an increase
in contractility
exogenous catecholamines)
—
inotropic
and afterload do not
(through endogenous or
results in an increase in the force
of contraction, myocardial oxygen uptake, and cytoplasmic
calcium concentration."
Wall Stress
=-^,
are
2T
where
and
r
T=
=
ventricular cavity radius,
•
February
positive
Agents
that increase contractility
inotropic
agents
and
include
epinephrine, dopamine, and dobutamine."* However, these
P = blood pressure,
agents are not pure inotropes because each
may also increase
heart rate and/or systemic vascular resistance.'^
wall thickness.
Respiratory Care
considered
-"
"96
Vol
41
No
2
119
.
CARDIORESPIRAIORY INIERACTIONS
19.
In Conclusion
Babu A.
Chem
we have described cardiovasculai' anatomy
In this review,
20.
and physiology, hemodynamics, and myocardial pcrlbiTnancc.
By examining
one is
point,
patients t'riim
anatomic and pliysioiogic stand-
lui
2
1
.
physiologic
state.
(iulati
J.
The
control of
muscle troponin C.
Biol
J
1987:2621 12):581.s-5822.
Eisenberg E. Greene LE. The relation of niuscle hiochemisiry w
ilh
Eisenberg E. Hill TL. Muscle contraction and free energy transduction
biological systems. Science I9S.S;227(469()):999-I006.
in
22.
Tada M. Kat/ AM. Phosphorylation of the sarcoplasmic reticulum
and sarcolemma. Annu Rev Physiol 1982; 44:401-423.
23.
Opie LH. MyiKardiai contraction and
physiologic condition of the patient des|iite frequent, and somein
fast
muscle physiology. Annu Rev Physiol l9S();42:293-3()9.
better able to monitor and assess the patho-
times rapid, changes
HH,
Scordilis SP. Sonnenblick
myocardial contraction with skeletal
New
iology and metabolism.
24.
REFKRENCKS
WG,
Nayler
The
relaxation. In:
heart:
phys-
York: Raven Press. 1991:176.
Williams AJ. Relaxation
in heart
Some mor-
muscle;
phological and biochemical considerations. Eur
J
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Publishing Co. 1985,
RESPiKAfoKY Care
•
February
4!
No
2
CARD10RESPIRArC)R\ INTERACTIONS
Glossary for Cardiovascular Anatomy
actin: a protein
component
the fibers of muscle cells. Actin boinul to
tial
which make up
ot thni tilanicnts.
precursor of fiber shortening
myosin
— muscle
is
the essen
&
Physiology
increase mycKaidial contractility (inotropic state) or para-
doxically decrease
it,
in certain patients.
contraetioii.
contractility: inotropic state of the myocardium.
af'terload: formerly, the arterial pressure or
some
oihei-
cnereome while
sure of the force that a \entricie must
con-
related to preload
monic artery impedance, peripheral vascular resistance, and
mass and viscosity of blood. It is now more rigorously ex-
tractility
dial
It
by Laplace's
Law from
internal ladius
ami wall thick-
losa of the adrenal cortex. Its
major action
to facilitate potas-
is
exchange for sodium in the distal renal tubule, causing
sodium reabsorption and potassium and hydrogen loss. Its
siimi
it
cular
is
stimulated by angiotensin
may
\
myocar-
oxygen uptake, and cytoplasmic calcium concentration.
the ability or property of
is
muscle
to shorten or ilevelop
increased tension.
On
tricles.
and
con-
in
through endogenous or exogenous catecholamines
diastole: the period during
aldosterone: a steroid homione produced by the zona glomeiti-
release
as heart rale,
required to produce the transmural (across the
is
pressure required for systolic ejection.
heart)
As long
results in an increase in the force of contraction,
pressed in terms of the wall stress--ie, the tension per unit
ness) that
aftcrload.
oi-
preload, and al'terload do not change, an increase
cross-sectional area in the ventricular muscle fibers (calculated
term
mea-
it
during systolic ejection; contributed to by aortic or pul-
tracts
A
used to describe the intrinsic pi'operties of the muscle not
be active
in
II,
the
(between the
left side,
left
which the
atria
diastole begins
empty
when
into the ven-
the aortic valve
\entricle and aorta) closes and ends
when
systole begins with the closing of the mitral valve (between
the
left
w ith
atrium and ventricle). Diastole alternates rhythmically
systole or contraction of the heart.
a potent vasoconstrictor,
regulating arterial pressure and intravas-
ejection fraction, systolic: the fraction of the blood volume,
contained
olume.
during
its
in the \ entiicle at the
end of
dia.stole, that is expelled
volume divided by endvolume, normally 0J5-0.m. ie, 75-80%. With the
contraction,
the stroke
ie,
anjjiotensinogen: precursor of angiotensin: a tetradecapeptide
diastolic
formed by the
onset of congestive heiul failure, the ejection fraction decreases,
liver (formerly
a-globulin) that
angiotensin
is
considered to be a circulating
converted by renin to angiotensin
I
and/or
sometimes
to as little as 0,10
(
10%).
in
severe cases.
II.
excitation-contraction coupling: the release of calcium ions
atrioventricular (AV) node: a bundle of specialized muscle cells located at the junction of the atrial
lar septa.
The
AV
and ventricu-
node provides the only normal
atrio-
ventricular electrical connection, delaying the signal from
the sinoatrial
and
fill
node
to
allow the
atria
adequate time to empty
myosin. This
muscle contraction and
is
is
to facilitate
an essential step
in
also one that can be altered by dis-
eases of the heart muscle and by the administration of cate-
cholamines and aminoglycosides.
inotropic state:
cardiac index: the amount of blood ejected by the heart
in
of time (cardiac output, L/min) divided by the body
surface area; usually expressed in
ful for
the binding of actin to
the \entricles, prior to the initiation of ventricular
contraction.
a unit
from the tubules of the sarcoplasmic reticulum
L min
isovolumetric contraction:
ventricle
standardizing measurements of cardiac output so that
volume)
comparisons among patients of different
in"-. It is
si/e are possible.
In the left heart,
from the time
the mitral valve closes until the aortic valve opens, the
use-
'
.See contractility.
in the
is
contracting.
However, no blood
is
until the pressure in the left ventricle
outflow
tract (aorta),
left
ejected (iso-
exceeds
that
causing the aortic valve to open
and allow ejection.
cardiac output: the amount of blood ejected by the heart
a unit
of time, usually expressed
in
in
isovolumetric relaxation: the period of constant ventricu-
L/min.
lar
volume from
the time aortic valve closes until the mitral
catecholamines: pyrocatechols with an alkylamine side chain.
valve opens again.
Examples of biochemical interest are epinephrine, norepinephrine, and dopamine and dohulamine. These agents can
tricle
Respiratory Care
•
Febriiary
"% Vol 41 No
2
A rapid pressure drop occurs
in the
ven-
because of myocardial relaxation without a concomi-
tant \iilume chaiiize.
121
.
Cardiorespiratory Interactions
Laplace,
Law of:
In the intact heart, ventricular wall stress
= afterload =
preload: the amount of stretching the myocardium undergoes
prior to contraction.
It is
diastolic ventricular
2t'
where
and
=
r
T=
is
P = blood
ventricular cavity radius.
estimated by the measurement of end-
volume.
In the intact heart, the stretch
proportional to the volume of venous return delivered to
the ventricle during diastole.
pressure,
wall thickness.
renin-angiotensin system: the humoral effectors of vascu-
myosin: one of the proteins of muscle
traction. Its binding to actin
change
fiber essential for con-
and subsequent conformational
results in muscle-fiber shortening
known
as muscle
contraction.
lar
tone and volume. Renin, synthesized in the adrenal cor-
tex, is released in
and stimulates the production of angiotensins. These hormones
act to raise ventricular
their direct action
Ohm's Law:
See Vascular resistance:
R=
is
response to hypoperfusion and hypotension
the blood-flow analogue of
sarcolemma:
Ohm's Law. which
unit of current. If
some
is
the
membrane
of muscle cells (myocytes).
states that
the ratio of the drop in
distance of the wire for each
one extrapolates, vascular resistance
is
the
ratio of the pressure gradient across a capillary bed to the blood
flow through
indirect action through
aldosterone.
AP
the resistance of a conducting wire
electrical potential across
volume and blood pressure through
on the vessels and an
sinoatrial (SA) node: the origin of the electrical stimulus that
causes myocardial contraction
a
—
the heart's pacemaker.
bundle of specialized myocytes located
in the right
It is
atrium
near the junction of the superior vena cava.
it.
stroke volume: the volume of blood ejected from the heart
Poiseuille's
Law:
If all
other factors are held constant, the
with each contraction, expressed
in liters.
rate of flow (Q). through a cylindrical tube of length. L. and
radius,
/, is
directly proportional to the driving pressure,
the pressure difference
down
AP.
the length of the tube:
supraventricular tachycardia: a higher than normal heart
rate that originates
'above the ventricle',
or atrioventricular node or the atrium
Q =^i£__?, or
more simply,
Q
=
ie,
in the sinoatrial
itself.
—
R
rjLS
systole: the phase of the heart beat during
This implies that cardiac output or blood flow
is
directly pro-
portional to the force of myocardial contraction.
cles contract. In the left ventricle,
it
is
which
the
\
entri-
the period that begins
with the closure of the mitral valve and ends
w ith the
closure
of the aortic valve.
phosphorylation: a biochemical process by which adenosine tnphosphate
(ATP) donates
its
tenninal energy-rich phos-
transmural pressure: pressure inside
phate group to any of a number of acceptor molecules, enabling
ture
them
bonds
(eg,
tein kinases in the
(
ie.
phospho-
oxidation) of various substrates (pro-
sarcoplasm of muscle
myosin, ATPase, and calcium channels
myocardial contractu itv.
122
a
compressible struc-
on the structure from outside.
Pml^'exl-
pyrophosphates) from the energy released by
the dehydrogenation
late
the pressure exerted
subsequent enzyme-catalyzed biochemical
to take place in
reactions. In myocytes, formation of high-energy
ric
minus
cells)
to
vascular resistance: See
Ohm's Law.
phosphory-
cause increased
ventricular tachycardia: ventricular contraction emanating
from a focus located
in the \'entricle.
Respirators Care
•
February
"96
Vol 41 No
2
The Role of Cardiorespiratory Interactions
Donald R Black MD, Barbara
G Wilson MEd
Care
in Respiratory
N Meliones MD
RRT, and Jon
Introduction
—
Oxygen Transport & Utilization Supply
Oxygen Delivery The Supply
Oxygen Content
—
& Demand
Cardiac Output
Preload
Contractility
Right Ventricular Afterload
Left Ventricular Afterload
Oxygen Consumption
—The Demand
Effect of Cardiovascular Abnormalities on Do,, Vo,,
In
diovascular and respiratory systems function together
Introduction
changes
The importance
L-ardiorespiratoi^ interactions in
iif
agement of critically
ill
patients
& Vco:
Summary
now
is
recognized.
tlie
in
one system lead to changes
—how
in the other.
man-
The
car-
Oxygen Transport
&
Utilization
—Supply & Demand
diovascular and respiratory systems are intimately entwined
and have as
to
common
goals the delivery of adequate oxygen
meet the metabolic demand of the
of carbon dioxide.'
'
tissues
When oxygen
equate to meet the oxygen
and the elimination
deli\ery
demand of the
(DoO
is
inad-
tissues, anaerobic
metabolism occurs. Anaerobic metabolism
results in the pro-
Oxygen
is
transported to the tissues
by the tissues for aerobic metabolism.
gen delivered
output
(CO.
minute, and
).
to the tissues
the
the
''"*
blood and
in
used
depends primarily on the cardiac
amount of blood ejected from the
oxygen content of this blood
D03 can be
is
The amount of oxyheart each
(Q,(>). and. there-
altered by changitig either the
CO.
or
duction of lactic acid, and the resulting metabolic acidosis can
fore.
lead to multioigan dysfunction."" Acidosis causes a fmlher reduc-
Do^can be considered the "oxygen supply." The formulas used
tion in
Do: or
results in maldistribution of
blood flow. These
to calculate these values are
given
in
Table
I
.
C;,o:-
The major com-
a cascade of worsening Dq,- Under-
ponents of C,,c), lue oxyhemoglobin saturation (S^o;) '^^ hemo-
standing the mechanisms of oxygen delivery adequate to meet
globin concentration (Hb). Tlie partial pressure of oxygen dis-
abnormalities can result
in
the tissue needs requires an understanding of
how
the car-
solved
in the
pkisma (PioO contributes
little
to CaO: at sea level.
Another important component of oxygen
utilization
is
oxy-
gen consumption (Vq;) or the arnount of oxygen used by the
tissues for aerobic metabolism. V(), can be considered the
Dr Black was Senior Fellow
was
wrilten.
He
is
now
Springfield. Missouri.
in
Pediatric Critical
this
paper
"oxygen demand' of the patient. The relationship between
oxygen supply (Dq:) and oxygen demand Vq:) is critical,
(
in private practice at St
Dr Meliones
is
Anesthesia. Medical Director of Pedi
Chief Pediatric Critical Care;
Critical
Care when
Ms
''
ssociate Professor of Pediatrics
iric
Wilson
Center,
&
Respiratory Care, and Division
is
and abnormalities
in this
relationship result in pathophysi-
ologic disturbances.'
Research Associate. Pediatric
Care and Respiratory Care Services
Duke University Medical
John's Health Center.
— Duke Children's Hospital.
Durham. North Carolina.
N Meliones MD. Duke Children's Hospital. PC Box 3046.
Duke Universitv Medical Center. Durham NC 2771(1.
Reprints: Jon
Respiratory Care
•
February
"96
Vol
41
No
2
*See Glossary following the References section.
123
^
I
Cardiorespiratory Interactions
Table
hirmulas
1.
ConmumK
L'sed
To Assess Cardiovaseular Function
Symbol
Variable
Arterial
oxygen content (ml,
Formula*
CaO:
Cardiac output (niL/tiiinl
CO.
Oxygen consumption (ml./min)
Vo:
Oxygen
Dq,
delivery (niL/mlni
(
.34
1
X Hb X
CO. X
(C,0; - Cto:)
C.O.xCo:
(
CpcO;
(CpcO:
Qpa
Starling forces
P^o,)
Volume
Heart rate x Stroke
Qs£
Shunt fraction (niL/mni)
+ (0.003 x
SaO;)
(mm Hg)
- CaO ;)
~ CvO;)
K[(Pcap -P,m)-0(ff.a,,-'r„„(|
Venous oxygen content (ml,l
(1..M
CvO:
X Hb X Su,,) + (0.003 X
P,o,)
blood flow;
'Sao; = o-\yhenw2lobin saturation of arterial blood; PjO; = partial pressure of oxygen in arterial blood; Cjo. = mixed-venous oxygen content; 0,>, = systemic
= retlection eoefficicnl representing the ability of the capilQpa = pulmonary blood How; CpcO: = pulmonary capillarv oxygen content; K = protein-nitraluin coelTicient;
=
lary wall to block protein migration; Pcap = capillary hydrostatic pressure; Pi„, = Interstitial hydrostatic pressure; ;!^jp = colloid osmotic pressure of proteins in blood; ;ri„,
colloid osmotic pressure of proteins
Oxygen Delivery
in interstiiium;
SvO; = oxyhemoglobin saturation of venous blood; Pvo; = partial pressure of oxygen in venous blood.
—The Supply
Under usual
not alter the heart rate
Oxyjjen Cctntent.
ration
oxyhemoglobin
satu-
or hemoglobin concentration result in signifi-
(S.,c);)
cant increases in
contributes
increases in
Siiuill
little
Cao- However, because dissolved oxygen
to the total oxygen content of the blood, at
standard temperature and pressure, increases
in
PaO: effect
only a small increase in CaO:- The primary mechanism for
increasing Cjo,
is
to increase
Sao. This
is
do
clinical conditions, respirator) inter\ entions
rate (KX'urs with the
even though minor
phases of breathing
—
\
ariation in heart
slows during inspi-
it
ration and quickens during expiration because of the changes
However,
that breathing induces in intrathoracic pressure.
respiratory interxentions can significantls alter Do- by their
effect
on the determinants of stroke \olume
— preload, con-
tractility, and afterload (Table 2).
usually accomplished
by increasing the fraction of inspired oxygen
Table
(Fio;).
Respuatory Interventions To Imprine Oxygen Delivery
2.
Breathing higher-than-rooin-air concentrations of oxygen
T Stroke
can
result in a reduction in pttlmonar\' \ascular resistance sec-
ondary to a reduction in pulmonary artery pressure. However systemic arterial pressure and vascular resistance may
increase.
The
increase
tion in heiirt rate
tion in cardiac output.
an important role
who have
in aortic
pressure
restills in a
and stroke soiume and the potential
These physiologic changes may play
in the
management of
infants
HFJVifPa„>
exhibit a decrease in
gen causes pulmonary
monary bkxxl
nov\ to incivase
at
(
15-20 mL/kg) i
Pa,
T
pH
T PIP. Pa„
TVt( 15-20 mL/kg)
Oxide
Nitric
heart syn-
in Fk),.
tiscular resistance to fall
\
T V,
cm H:0
tP,W:.PaO:
T Expiratory time
and children
left
Do, with increases
rate!
4-
10-15
TComractilitv iPIP.Paw
i Afterload
congenital heart disease with intracardiac shunt.
For example, many patients with hypoplastic
drome
i Paw" (J^PEEP.
T Preload
reduc-
for reduc-
Left Venlricle
Riatit Ventricle
Vol time
Oxy-
and pul-
Pj„ =
mean air«a\
volume;
HFJV =
pressure;
PEEP = positive cnd-expiraUiry
high-frequency jet ventilation; PIP
partial pressure ol alveolar
pressure;
= peak airway
oxygen; Pao; = panial pressure of
V| =
tidal
pressure; PaO: =
arterial
oxygen.
the expense of systemic bkxKl
flow. .Mthough these patients de\elop ele\alcd Cao- because
of the higher SaO:- Do;
reduced systemic
CO.
is
actualls decreased because ol'the
This example serves to underscore
the impoilance of utKlctsltintling the cardiorespiiatory effects
of respiraloty interxentions. CaO;- although important,
one
only
hean o\er
earlier, is the
124
CO.
\
olume
in the heart prior to
Increasing ihe \oltime
contraction
in the \entricle
stretch of the \entricular
Fig.
(
).''''
1
(preload) results in
myocardium, which increases the
force of contraction and causes an increase in stroke vol-
ileleniiinani of Dq:-
Cardiac Output.
the
is
Preload. Stroke \olume can be altered b\ changing the
anuHini of
is
a unit of time
the quantits of blood ejected by
(commoiiK L/min) and.
as staled
product of the heart rate and stroke xnlume.
decieased. the tbrce ot con-
ume. Con\
ersel>
traction
decreased, and stroke \i)lume
is
does not change.
stroke
\
.
if
preload
CO.
is
falls. If
heart rate
follows the increase or decrease
in
olume.
Respir.vior^
Care
•
February
"96
Vol
41
No
2
:
Cardiorespiratory Interactions
conditions in which
End-Systolic Pressure-Volume Curve
left
ventricular preload
can augment
right ventricle
left
decreased, the
is
ventricular preload because
of this series relationship.
I
There
E
E
no
is
ventilcle in seiies with the tight ventricle. There-
fore, small pressure gradients
right atrium
ular filling.
can result
When
resistance to flow
2).
As
in
between the systemic veins and
dramatic changes
the right atrial pressure
in right ventric-
zero, there
is
and systemic venous return
right atrial pressure increases, there
is
is
is
no
inaximal (Fig.
increased resis-
End-Diastolic
Pressure-Volume Curve
tance to flow resulting in decreased venous return and tight
ventricular preload.
Left Ventricular
Fig,
1,
Volume (mL)
changes
ventricular
in left
pressure during the cardiac cycle. During diastole the
and
left
volume (preload)
at Point A. During the
tion
A
to Point
is
first
— the pressure
occurs
left
ventricle
ventricular pressure increases from Point D, along the
end-diastolic pressure-volume curve,
diastolic
E
volume during the carand the Y-axis depicts the changes in left ventricular
diac cycle,
fills,
X
of tfie left ventricle. Tfie X-
Pressure-volume relationship
axis depicts the
B
with no
reached
phase
in
change
the
in
until
the
left
Spontaneous Breathing
ventricular end-
Systole
at Point A,
is
initiated
of systole, isovolumetric contracleft
ventricle increases from Point
ventricular volume. At Point B.
ABC
left
ventricular pressure increases greater than aortic pressure, the
opens, and left ventricular ejection occurs. As strol<e
volume is ejected from the left ventricle, the left ventricular volume
decreases until the pressure-volume curve intersects the end-systolic pressure-volume curve (Point C). At Point C. systole ends and
diastole begins. Left ventricular pressure decreases with no
change in ventricular volume (isovolumetric relaxation), and the
aortic valve closes as left ventricular pressure decreases to Point
aortic valve
D. This cycle
is
then repeated with the area within the
equal to the stroke worl< required to eject the
ABCD
loop
—
volume volThe stroke volume
strol^e
ume at Point A minus the volume at Point B.
can be increased by increasing the volume in the ventricle prior to
contraction (end-diastolic volume or preload). When the left ventricle IS provided with an increased volume, the preload is increased
to Point A'
pnor to contraction. As the ventncle contracts, isovoluuntil it achieves a pressure B' that
metric contraction again occurs
to overcome atterload. If afterload has not changed.
and the remainder of the pressure-volume relationship is as
before. However, the stroke volume is increased and is equal to
the difference between the volume at A' and the volume at D, The
increased stroke volume due to the increased preload is reflected
by the shaded area. (tVlodified from Reference 6, with permission.)
is
necessary
B=
(Maximal)
Venous Return
Venous
Fig. 2.
return to the right heart occurs passively
pends on a pressure gradient from the systemic veins
When right atrial pressure (Pra) is zero, there is no
impedance to flow back to the right heart, and venous return is
maximal (Point A). As right atrial pressure decreases, and mean
systemic venous pressure (Pvems) is held constant, there is a progressive reduction in venous return. When right athal pressure exceeds mean systemic venous pressure, venous return ceases.
Dunng spontaneous breathing, right atrial pressure is low and systemic venous return is high (Point B). During positive pressure
ventilation (PPV). intrathoracic pressure and P,a increase resulting
in reduced venous return (Point C). (Modified from Reference 2.
atrium.
with permission.)
B',
During spontaneous breathing,
and there
heart.
is little
right atrial pressure is low,
resistance to flow into the right side of the
During PPV. the increased intrathoracic pressure
mitted to the right he;ul. causing an increase
Positive pressure ventilation
changes
in
(PPV) can cause
both light sentncuku- and
influence of PPV on nght ventriculai' preload
Venous
sive
significant
left \'entncLilai' pi'eload.
is
Tlic
well documented.
return to the right side of the heart
is
The
same as
right atrium.
determinants of right ventricular preload are not the
left
because
venous
ventricle operates in series with the right ventrileft
return,
ventricular preload depends on
which
Respiratory Care
is
•
pulmonary
derived from the right ventricle. In
February
"96
Vol
CO.. and
CO.
PPV
(PEEP) can decrease
trans-
venous return
and positive end-expi-
right ventricular preload.
Dq,.
can be variable, particularly
ventricular dysfunction.
A
in patients
with right
reduction of right ventricular
may result in a marked decrease of
may benefit from ventilation strate-
preload in these patients
D02, and these patients
gies that reduce intrathoracic pressure and increase preload.
the determinants of left ventricular preload.
The
atrium (preload). Thus,
ratory pressure
relatively pas-
and occurs primarily because of the pressure gradients
between the systemic venous system and the
to the right
is
in right atrial pres-
sure. TTiis increase in right atiial pressure reduces
cle
and de-
to the right
41
No
A
more dramatic response
in patients
to these ventilatoi^
with right ventricular dysfunction
is
manipulations
seen in patients
with hypovolemia.
125
CARDIORESPIRATORY' INTERACTIONS
The changes
to
PPV
occur
that
in left ventriciiliu-
preload in response
are not well understood. Investigators
have proposed
three physiologic principles lo support the notion that left ventricular preload
is
PPV
decreased during
can only eject the
ventricle
left
because right ventriculiu- output
it
ventricular preload
The
1 )
(
receives
There-
decreased dunng PPV.
is
amount of blood
the left ventricle receives a decreased
left
that
right ventricle (\cntricular interdependence).
from the
fore,
and PEEP;
of blood
quiintity
antl
Right ventricular afterload
falls. (2)
and systolic pressure increase during PPV. The increase in
right ventricular pressure results in conformational changes
in the intra\entricular
compliance
septum and a decrease
produce a reduction
that
in left
ventricular
preload. (3) Because
in
of the increase in intrathoracic pressure, direct compression
of the
left \
One
and improve
left- ventricular
heart
left
can result
in
compression of lung contents.^ Compression of lung contents
results in blood's
being forced into the
left
side of the heart
resulting in augmentation of left heart tilling.
augmentation
Thoracic-pump
a high-liiial-\'olume ven-
accomplished with
is
tilatory strategy (V-,
- 15-20 niL/kg). However,
contribute to ventilator-induced lung injui^
this strategy
if
high peak-
airway pressures are generated.''
Contractility. Another important modulator of stroke \ ol-
ume
is
the contractile or inotropic state of the
myocardium.
a negative inotrope (eg.
For any given preload and afterload.
propanolol) decrea.ses the force of contraction and decreases
CO.; whereas,
a positive inotrope (eg,
dopamine) increases
the force of ventricular contraction and increases
determinant of contractility
the
is
the
CO. One
amount of blood How
to
myocardium, or the coroniuy blood flow. Right ventricular
coronaiy flow occurs primarily during systole and. therelore.
depends on the difference
in systolic
aorta and right \entnclc. Because
pressure between the
PPV
results in increased
right ventricular pressure, the pressure dilference
the aorta
and
right ventricle
is
between
decreased, and right ventric-
tractile force.
As a result, right ventricular conCO.. and Do, decrease when intrathoracic pres-
sure
PPV
ular coronary flow falls.
cle
is
high.
(LV)
has
v
ery
little
direct effect
on
left ventri-
contractility.
Right Ventricular .Xfterload. The force opposing
tricular ejection
is
the
v
afterload
load
is
is
is
v
en-
ascular resistance or afterload. This
has been an area of intense investigation
tion
circuit
— pulmonarv
vas-
ume
in
is
low, pulmonary vascular resistance
is
high because,
the under-inflated lung, blood vessels that supplv the lung
are long
and tortuous and because hypoxic pulmonary vaso-
constriction
lung
V
olume
is
also present at low lung
decreases,
decreases.
and pulmonary vascular resistance
As lung volumes continue
capillaries,
increases.
As
hypoxic pulmonary vascK'on-
llalion of the alveoli can occur, with
monary
(Fig. 4).
increases, the blood vessels lend to straighten,
their capacitance increases,
striction
volumes
The
total
and resistance
to increase, hyperin-
compression of the pulin
these small vessels
pulmonai'y vascular resistance
is
a func-
preload con-
Cardiopulmonary resuscitation research has demi)n-
strated that an increase in intrathoracic pressure
may
pulmonary
tion of both small- and laree-vessel resistances.
entricle occurs that can reduce preload.
of using thoracic-pump augmentation to impro\e
filling.
ol the
Pulmonary vascular resistance is influenced
by several factors, including lung volume. When lung vol-
respirator) intenention designed to counteract the neg-
ative effects of PPV
sists
by the resistance
cular resistance.
in recent years.
When
increased, the force opposing ventricular ejec-
increased, and stroke
volume
tails (Fig. })}'
If after-
reduced, the force opposing ventricular ejection
reduced, and
CO.
increases. Right
v
is
entricular performance
has been extensively studied and responses lo small changes
in afterload
with significant changes
been documented. Rinht
v
in
CO.
entricular afterload
and Do: have
is determined
End-Systolic Pressure-Volume Curve
Cardiorespiratory Interactions
ventricular preload and an increase in right ventricular after-
may
load. Ventilatory strategies to induce alkalemia
require
high levels of intrathoracic pressure. Various ventilatory
have been employed
strategies
pH
Total
that has been used successfully
PVR
attempts to alkalinize the
in
One
while minimizing intrathoracic pressure.
frequency
jet ventilation.
strategy
in this clinical setting is
high-
High-frequency jet ventilation has
been shown to reduce pulmonary vascular resistance comLarge Vessel Resistance
pared to
PPV
These
in selected patient populations.'"*
were primarily related
to the reduction in
effects
mean-airway and
intrathoracic pressures that occuired during high-frequency
Complete
FRC Lung
Maximum
Collapse
Volume
Expansion
compared
jet ventilation
tricular afterload
Fig. 4.
Pulmonary vascular resistance (PVR) depends on lung
ume and
the
sum
of the resistances contributed
PPV.
to
Another respiratory intervention
vol-
by the large
to
medium-sized pulmonary vessels and pulmonary capillaries. At
lung volumes less than functional residual capacity (FRC), PVR is
high due to hypoxic pulmonary vasoconstriction and the increased
resistance contributed by the tortuous large and medium-sized
vessels. As lung volume increases compressing the pulmonary
capillaries, PVR falls. High lung volumes are associated with an
increase in PVR due to increased resistance contributed by compression of the pulmonary capillaries. (Modified from Reference
20, with permission.)
Nitric oxide
(NO)
is
is
alter right ven-
an endothelium-derived relaxation fac-
selective vasodilator that
inhaled,
The systemic
properties of
is
rapidly inactivated
a non-
is
reduction in pulmoniuy vascular resistiuice.
circulation
NO because
it
protected from the vasodilating
is
is
inactivated
reaches the systemic circulation.
monaiy
NO
by hemoglobin.
NO causes rapid dilation of the pulmonaiy iuter-
ies that results in a
it
can
can be administered as an inhaled gas.'-"'
tor that
When
that
the inhalation of certain medical gases.
va.scular resistance has
by hemoglobin before
A prompt reduction
been demonstrated
in pul-
after inhala-
NO by newboins with primary pulmonary artery hyper-
tion of
tension and in patients with pulmonary artery hypertension
after surgery for congenital heart disease."
ratory time should be as long as possible in patients with right
ventricular dysfunction.
One of the most
It
successful approaches to reduce right
ventricular afterload
is
the manipulation of cardiorespira-
tory interactions to lower
Therapy directed
sists
pulmonary vascular
resistance.
reducing right ventricular afterload con-
of increasing pH. lowering PaCO:- increasing alveo-
and
lar
at
ide
arterial partial pressure
of oxygen, and minimizing
Some studies suggest that increaspH significantly reduces right ventricular afterload.
Drummond et al'"" showed that by reducing Paco; to 20
torr and increasing pH to 7.6, a consistent reduction in pulintrathoracic pressures.
ing
is
pH
at
40
torr,
however, been used
has.
CO:
anism (respiratory or metabolic)
pulmonary
can also result
affects
oxygen delivered
These effects are more dramatic
to the
airway (Fdo:)
in
neonatal and pediatric
Animal studies have demonstrated
more potent pulmonary vasodilator in
patients than in adults.
that
oxygen
is
neonates than
it
a
is
in
adults," Respiratory manipulations
designed to decrease afterload should be accomplished
at
the lowest intrathoracic pressure possible because an increase
in
intrathoracic pressure
Respiratory Care
•
may
in
pulmonaty
result in a reduction of
pulmonary
results in
an increa.se
blood flow and more stable shunt flow
in patients
with a sin-
gle ventricle.
Left Ventricular Afterload. Left ventricular afterload
depends on
left
—
— and
ventiicular myocardial wall tension
sure generated by the ventricle during systole
the presis esti-
mated by' ^'"
left
ventricular afterload
= Piv -
Pimraihoracic.
where Plv =
may
result in a decrease in right
February
'96
Piniraihoratic
=
left
ventricular systolic pressure and
intrathoracic pressure.
pulmonary vascular
a reduction in right ventricular afterload.
in
Paco:
vascular resistance and
resis-
increase in both Pao: i»nd PaO: by adjust-
ing the fraction of
with congenital heart
7.5-7.6 while maintaining PacO:
resulted in a similar reduction in
An
in patients
concentration results in an increase in Paco: and PaCO:-
In addition, increasing
tance indicating that alkalemia. irrespective of the mech-
resistance.'-
Carbon diox-
disease to reduce pulmonar}' blocxl ni>w.'-'^ Increasing inspired
monary vascular resistance and right ventricular afterload
was achieved. In addition, manipulating serum bicarbonate levels to achieve a
'^
rarely used as an inhaled gas in the intensive care unit.
Vol 41 No
2
Left ventricular afterload can be reduced either by decreasing aortic pressure and, thus,
left
ventricular pressure or by
increasing intrathoracic pressure.
The
effects of
PPV
on
left
ventricular afterload
is
com-
plex because the systemic arterial system has both intrathoracic
and extrathoracic components. As intrathoracic pres-
sure increases during
sure
is
PPV,
the increased intrathoracic pres-
transmitted to the intrathoracic blood vessels. Left
ventricular wall tension remains the
both the Pi V generated and the
same because
Pintrathoracic
the changes
generated are equal.
127
Cardiorespiratory Interactions
ing depends on the adetjuacy of ventilator-patient synehroni/ation.
For example,
When a patient's spontaneous breathing effort is not synchrowail tension =
LV
Plv
(
K'lJ
mm Hg) -
P.mraihi.racic
(
10
w ith
ni/ed
mm Hg) = 90 mm Hg.
the ventilator-initiated breaths, an increase in
Work
of breathing and Vq^ occurs.
of breathing occurs
work
when
respiratory muscle contraction persists through inspiration, -ir
intrathoracic pressure
mm
increased by 30
is
Hg,
Effect of Cardiovascular Abnormalities
LV
Pi
V
(
1
30
mm
Hg) -
=
wall tension
P„„r.,ih„racic (41)
on
mm
mm
Hg) = 90
Changes
However, the extralhoracic
increase in ailerial
system also
arterial
pressure due to propagation of the increased
When
intrathoracic pressure into the peripheral circiut.
increase in intrathoracic pressure results
in ailerial pressure, aoilic
nomic
elops an
ile\
pressure
is
ner% ous system, decreasing
the
marked increase
a
in
autoregulatetl b\ the auto-
LV contractile
loree by stim-
ulation of aortic baroreceptors.'*''^ This results in a retlex
aortic pressure and reduction of
decrease
in
pressure.
When
aortic pressure falls
due
pressure gradient
ilial
falls.
to this reflex action,
effect
For example
on
CO.
tem has on
Pi
V (100
mm
Hg) -
P,„,n„honK.c (10
Hg) = 90
mm Hg.
mm
Hg and
tem as
in
It
aortic pressure returns to 100
mm
Pl\
100
(
mm
Hg)-
=
wall tension
P„u.aiho,.,cic (-10
and
mm
Hg.
C.,o,.
in the
govern the flow of
(Table
interstitiuin
tluiel in
).-'-^
1
in
the capillaries
in
forces,
and because
force to
the interstitium.
-
persistent increase in intrathoracic pressure results in a
decrease
in left ventricular afterloati
sure auloregulation.
these
complex
Under usual
because of aortic pres-
clinical contlitions.
interactions result in only a slight
change
ventricular afterload because intrathoracic pressure
left
compared
to left ventricular pressine,
over only 1-2 cardiac cycles, which
time tor autoregulation. However,
is
however.
if
is
in
low
and inspiration occurs
may
not allow
enough
intrathoracic pressmx'
high ami persists over multiple e;udiac cycles,
left
ventiieular
This
(F,ni)-
—The Demand
push
the hydro-
The
the
differences
greater than
usually results
P,,,,.
fluid shifts out of the capillaries into
force tending to
promote
tluid entiv into
osmotic
the ciilloid
is
pressure iliffcrence between the capillaries and interstitium
(
jz^jfi
-
Ttutt
This force depends on a number of factors includ-
)
ing the retlection coefficient
of the capillary
Under normal
is
membrane
stiiuim.
w hich
(0)
to
that quantitates the ability
block the passage of proteins.
contlitions, the net effect of Starling's forces
amount of net
to proiDote a small
is
tliix
then removeil bv the
ever, in conditions of
tricular dvsfunction
illaries
Con.suniptittn
is
opposed by
is
left atrial
of
Iv
lluitl
mph
in
mav
into the inter-
system.
hv pertension and/or
How-
left
ven-
(myocardial infarction, cardiomyopathy,
mitral stenosis) hydrostatic pressure in the
afterload can be reiiuced.
Oxygen
and out of the cap-
the net effect of the hydro-
Pint, is
P^-ip is
promote
The
(Pc;,,,).
the interstitium
P^.,,p
frequently
Tlie force tending to
of the capillaries and into the interstitium
pressure
is
intensive care unit. Star-
the capillaries anil out of the interstitium
A
the alv eolar level
be caused by the cardiov ascular sys-
who ;ire
in patients
hydrostatic pressure
in a net
nmi Hg) = 60
may
both of which reduce
.
static forces
LV
at
Cardiogenic or hydrostatic pulmoniiry edema
between these
Hg,
drugs can help
afterloail. In aildition. eciiain
pulmonary edema and maldistribution of puinionary
blood flow
fluid out
the
and respiiatorv mechanics. The
direct effect the cardiovascular sys-
C.O. can he increased by optimizing preload,
and
peifusion mismatch
static
the miralhoiacic prcssiue increases by 30
most
depends on matching ventilation and perfusion. Venlilation-
illaries
mm
Vc()2
C.O. Adequate gas exchange
to optimize
encountered
=
wall tension
the
is
D(),.
contractility,
ling's forces
LV
&
the cartliovasctilar system can cause signifi-
in
cant alterations in Do,, Vo,,
and the transmyocar-
ventricular systolic pressure falls,
left
ventricular
left
b(),,V(),,
Hg.
increase tiramatically.
When
hvdrostalic pressure in the capillaries
this
pulmonary cap-
(kcuin the increase
(1\,||,)
results in exces-
sive flow of lluid nito the interstitium due to Starling's forces.
to o|itimi/iiig the balance
Another approach
gen suppiv and oxygen ilcntand
D(),
the
is
to decrease the
oxygen needs of
oxygen demand of the
pcricxis
of respiratorv'
in patients
w
respiratory muscles
failure,
how ever,
compensate
ing the
in patients
between oxy-
Because the distance between the capillaries and the alveoli
compromised
is
the tissues. Normally,
this
is
low. During
oxygen demand can
increase dramatically. C;irdiovascular rescI^e
to
ith
mav be inadequate
with an alreailv low Do,. In reduc-
work of breathing, mechanical
ventilation decreases oxy-
gen needs and improves the balance between oxygen supply and
oxviicn demand.-"-' However, a reduction of the work of breath-
128
so small, excessive tluid in the interstitium communicates
through the
spaces to the perivascular and peri-
interstitial
bronchial spaces and across the alveolar epithelium into the
alveoli. \\
hen pulmonary edema and atelectasis
|X'rsisl.
m;uked
mismatch occurs, and gas exchange is
).-'-' A reduction in gas exchange
impaireil (West Zone
decreases arterial oxygen saturation, C-.o-, and Do,, and
ventilation-perfusion
I
increases Paco?- Cardiovascular dysfunction also results in
mechanics with a retluction in lung
alterations of respiiatorv
RE.SPIK \T()R^
CARF
•
FHBRI'ARY
'% VoL
41
No
2
.
Cardiorespiratory Interactions
Meliones JN. Snider AR. Bove EL. Rosenthal A. Rosen DA. Lon-
volume (primarily functional residual capacity) and a reduction in lung compliance. These changes may increase work
gitudinal results following after first-stage palliation for hypo-
demand
used
balance. Viirious
entilatory manipulations
\
w ith pulmonary edema,
to treat patients
IV-
ha\e been
including
at
However, the most
effective therapy
improN ing nnocardial peiformance and reducing
K.
The
end-systolic pressure-volume relation of the ventricle:
definition, modifications,
and clinical use. Circulation 1981:63(6):
1223-1227.
Sagawa K. Suga H. Shoukas .AA. BakaUir KM. End-systolic presratio: a new index of ventricular contractility Am J Car-
directed
is
15(1.
Sagawa
PEEP
and high-tidal-volume ventilation, to restore functional residual capacity.-
syndrome. Circulation 1990:82(5. Supp!):IV-15I-
plastic left heart
of breathing and Vq:- further worsening the oxygen-supply-
sure/volume
.
Pcap-''"''
diol 1977:40(5):748-753.
Another cardiovascular abnormality that results in respicompromise is a reduction in pulmonary blood flow,
Koehler RC. Chandra N. Guerci AD. Tsitlik
ratory
which must be adequate
bon dioxide
at
exchange of oxygen and
for the
monary
Zone
3).-'
This
'"*
in patients
w ith
occur
is
in patients
who
resistance.
P,,n:.
As described
and minimizing
ill
patients.
iol
Pmtraihoracic-
Summary
who care
With every intervention by
interactions.
feature
is
The
to illustrate the
respiratoiy therapists,
in patient
can be made to optimize these
importance of cardiorespiratory
16.
inter-
2.
New
Rohotham
Bamea
Appcl PL. Krani HB. Bishop M. Ahraliani
E.
JL. Lixleld
1
):
W. Holland
B. Pemiutt S. Rahson JL.
left
21
The
L.
MR.
4.
MK.
Roberts
Jr.
Chen TY. Kawai N. Wain
JD
Lang
Jr.
nitric
oxide
Dupus
P.
Shimouchi A.
in tlie
hypoxic
LM, Vlahakes
P. Bigatello
GJ. Zapol
WM.
in congenital heart disease. Circulation 1993:87(2):
Pinsky
MR. Summer WR.
in
hypoplastic left-heart
Cardiac augmentation by phasic high
Pinsky
man. Chest 1983:84(41:370-375.
MR. Summer WR. Wise RA. Augmentation of cardiac
by elevation of intrathoracic pressure.
Maclntyre NR.
Ho L. Weaning
J
func-
Appl Physiol 1983:54
mechanical ventilatoPi support. .Anesth
Maclntyre NR. Pressure support ventilation: effects on ventilatory
JJ.
Rodriguez
RM. Lamb
V. The inspiratory workload of
patient-initiated mechanical ventilation.
Rev Respir
arterial
How
variation dur-
Philadelphia:
23.
Aw
Rev Respir Dis 1986:
West JB. Dollery CT. Distribution of blood flow
relation to vascular
WB .Saun-
West
&
ders. 1981.
February
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134(51:902-909.
Guyton AC. Te.xtbook of medical physiology.
•
FW. Callow
Fontan procedure. Circulation 1991:84(5. Suppl):III-364-
EI-Lessy HN. Pulmonary vascular control
Marini
effects of positive end-respiratory
ventricular performance. .\m
Appl Physiol 1984:56(5): 1237-1 245.
Respiratory Care
Custer JR. Moler
447-457.
MacGregor D. Bromberger-
Determinants of pulmonary
ing respiration. J
Am Rev Respir Dis
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145-159.
Dis 1980;121(4):677-683.
Pinsky
lanibs versus sheep.
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Hemo-
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.3.
newborn
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20,
shock.
CO:
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40(7):737-742.
18
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1-20.
447-453.
to optimization of these inter-
interesting presentations that illustrate
et al.
Inhaled
these principles.
1
):
1
and acidotic newborn lamb. Circ Res 1993;72(2):246-254.
management of patients, describe how
outcomes due
We welcome
1984:7(
Inhaled nitnc oxide reverses pulmonary vasoconstnction
one measures these interactions, and demonstrate improve-
actions.
pulmonary vasodilator drugs.
m-368.
17
ments
JE. Neonatal
Meliones JN. Bove EL. Dekeon
after the
for critically
goal of the Cardiorespiratory Interactions
actions in the clinical
Pediatr 198l;98(4):
1973:34(3):318-323.
Custer JR, Hales
LR.
15
that attempts
J
I985;I32(2):326-33I.
cardiorespiratory interactions must be carefully considered
and measured so
Phibbs RA. The inde-
pulmonary hypertension.
Dev Pharmacol Ther
status.
vasoconstriction in
essential for clinicians
is
GA, Heymann M,\.
concentrations on hypoxic pulmonary
understanding of (he interactions of the cardiorespi-
ratory system
Gregory
Malik .AB. Kidd SL. Independent effects of changes
14
An
Intemiittent positive pres-
Rev Respir Dis 1985:132(41:880-884.
Drummond WH. Lock
Current
13,
In
Saumon G.
603-608.
include increasing pH. lowering Paco:-
increasing Pao: and
Am
Drummond WH.
infants with persistent
pulmonary blood
If
improve pulmonary blood flow are
pulmonary vascular
may
earlier, these
P.
after cardiac
pendent effects of hyperventilation, tolazoline. and dopamine on
11
directed at lowering
Dreyfus D. Bassett G. Soler
rats.
10.
inadequate, SaO:. CaO:, and Dq: are decreased. Res-
piratory manipulations to
1983:67(2):266-275.
with pul-
right ventricular
congenital heart disease
ha\e decreased pulmonary blood flow.
flow
aiTcst in dogs. Circulation
sure hyperventilation produces pulmonary microvascular injury in
pulmonary emboli,
artery hypiertension.
dysfunction, or
may
ventilated but not per-
is
Tray siman RJ. Rogers
J.
of cerebral perfusion by simultaneous chest
compression and lung inflation with abdominal binding
car-
the alveolar level. Ventilation-perfusion mis-
match occurs when a segment of lung
fused (West
MC, et al. Augmentation
"96
Vol
41
No
2
and alveolar pressures.
JB. Respiratory physiology
J
in isolated lung:
Appl Physiol 964; 19:713.
1
—
the essentials. Baltimore: Williams
Wilkins. 1979.
129
Cardiorespiratory Interactions
Glossary for The Role of
aerobic metabolism: a form of cellular respiration
molecular oxygen
are produced.
is
When
in
which
CRI
Respiratory Care
in
colloid osmotic pressure: also oncotic pressure: osmotic pres-
consumed and caibon dioxide and water
sure due to plasma proteins.
molecular oxygen
vent to
is
una\ ailable (anaer-
now from
Osmosis
is
the tendency of sol-
an area of lesser concentration of solute to
obic condition), the rate of cellular respiration increases but
one of greater concentration of solute. Osmotic pressure (k)
becomes
then
less efficient,
producing
can cause
lactic acid; this
is
measurement of
the
that
tendency.
profound metabolic acidosis and death.
congenital heart disease: existing
alkalosis: a pathophysiologic tissue disorder characterized
by
tlie
loss of
hydrogen
ions.
It
may
result
from increased
bicar-
bonate ion concentration (metabolic alkalosis), or by reduced
CO2 due to hyperventilation
in
blood
is
at birth, referring to
itary (genetic) or influenced
tation,
up
to the
moment
by e\ents occurring during ges-
of birth.
contractility: inotropic state of the
myociudium.
to describe the intrinsic properties
anaerobic metabolism: See aerobic metabolism.
to preload or afterload.
baroreceptors: nervous system tissue that
is
sensitive to pres-
sure .stimulation. In the circulatory system baroreceptors respond
and volume by
eliciting vasodilation
or vasoconstriction.
piratory system
It is
—
analogous
compliance of the
to
the capacity of a lung unit for
res-
volume
al
a given pressure.
as heart rate, preload, and afterin contractility
the force of contraction, myocardial
through endoge-
in
an increase in
oxygen uptake, and cyto-
plasmic calcium concentration. The ability or property of mus-
develop increased tension.
coronary blood flow: blood flow
myocardium: one
to the
of the detemiinants of right \entricul;ircontractilit\ (inotropic
state).
For example,
right ventricular coronary
flow occurs
primarily during systole and. therefore, depends on the systolic pressure difference
cardiac output: the amount of blood ejected by the
Uicle each minute.
and heart
A term used
of the muscle not related
nous or exogenous catecholamines results
cle to shorten or
capacitance: the capacity of an electrical circuit to hold an
As long
do not change, an increase
load
electrical charge.
anoma-
be either hered-
(respiratory alkalosis). Alkalosis
termed, alkalemia.
to regulate blood pressure
may
of the cardiovascular system, which
lies
is
It
the product of the stroke
left
volume
ven-
(LTbeat)
rate (beats/min):
cle.
between the aorta and
During positive-pressure ventilation,
reduced because intrathoracic pressure
\entncular contractile force, cardiac
is
right ventri-
this difference is
increased and right
t)utput.
and oxygen deliv-
ery are reduced, as a result. Positive-pressure ventilation has
volume (L)
[-
X
beats
little
!i;i
nun
min
beat
effect
on entrinsic
left
ventricular systolic function.
high-frequency ventilation: positive pressure ventilation using
cardiomyopathy: degeneration of the
to contractile failure
unable to
pump
heart
— congestive heart
blood
at a rate
muscle
failure.
that leads
The
heart
is
high enough to satisfy the
metabolic demands of the body.
left
ventricle associated with
by signs of overall cardiac
as well as
by
its
systolic function of the
dilatation;
failure.
latory, or tlow-inteiTupter ventilators.
gests that the lower
mean-airway pressure required when jet
ventilators are used reduces
cardiomyopathy, dilated: decreased
\\
ith
usualK manifested
congestise findings,
fatigue. indica(i\e of a low output state.
may be jet. oscilSome literature sug-
frequencies higher than 150/min. Devices
hydrostatic pressure:
pulmonary
\
In the capillaries,
ascular resistance.
it
is
the force tend-
ing to push liquid out of the capillaries ami into the intersti-
tium
(Pc;ip). In
fluid out
the interstitium.
it
is
the force tending to
forces are opposing, and the difference between
cardiomyopathy, hypertrophic: thickennig of the ventricular
septum and walls of the
ril
left
ventricle with
free wall resulting in narrow ing of the left
ventricular outflow tract and
tolic
130
compliance
is
dynamic outflow
greatly impaired.
favors
P^:ap.
promoting a
them
(Pc.ip-
fluid shift towiird the interstitium.
marked myofib-
disarray; often associated v\ith greater thickening of the
septum than of the
Pint)
push
of the interstitium and into the capillaries (Pim). These
gradient; dias-
hydrostatic pulmonary edema: liquid
of increased
l\jp. In
conditions such as
ventricular dysfunction. Pcap
in the alveoli
left
because
atnal hypertension
high causing exces-
or
left
si\
e flow of lluid into the interstitium. the peribronchial space.
Respiratory Care
•
is
February '% Vol
41
No
2
—
—
)
Cardiorespirator'i Interactions
and across the alveolar epithelium into the
tilation-perfusion
mismatch produced
alveoli.
The ven-
results in impaired
oxygen delivered (Do,):
hypoplastic left-heart syndrome: a congenital maltorma
tion of the heart in
which the
left
ventricle
is
made
is
Do, depends piimiuily on CaO:-
cardiac output, organ blood flow
gas exchange.
which oxygen
the rate at
axailable to the tissues (I7min).
.
anil Fio;.
oxygen demand: See oxygen consumption.
essentially non-
functioning. In such conditions of ductal-dependent systemic
oxygen supply: See oxygen delivery.
blood tlow. increased F|0: can cause decreased Dq: because
of the resulting change
in the ratio
of systemic-to-pulmonary
positive inotrope:
an agent that increases myocardial
vascular resistance and blood tlow as pulmonary blood flow
inotropic state or contractility and. therefore, the force of
increases and systemic blood flow decreases.
myocardial contraction
inotropic state: See contractility.
preload: \olume of blood
It is
—
dopamine.
eg,
in the heiul at the stait
of contraction.
normally estimated using end-diastolic pressure and varies
Under normal circum-
intracardiac shunt: abnormal blood flow through the heart
inversely with intrathoracic pressure.
because of openings
stances, the liuger preload results in greater ventricular stretch-
absence of
1
in the atrial
and/or ventricular septa,
or more chambers, transposition of outflow
tracts,
ing and larger stroke volume.
and other anomalies.
pulmonary vascular
ventricular afterload: the force against which the \en-
left
tricle
must push
to eject the stroke
volume: depends on
left-
ventricular wall tension (the pressure generated during systole |Plv])-
estimated by Plv
It is
-
afterload.
PVR
It is
to vary with lung
volume, being highest
and very high lung \olumes and lowest
mitral stenosis: a reduction in the size of the mitral valve
left
atno\enlricular valve
—may
at
at
It is
very low
functional resid-
result in increased P^up and.
reflection coeflicient (0): a numerical value that quantitates
.
the capillary
an ischemic event
nitric
ual capacity.
eventualh hydrostatic pulmonary edema.
focal myocardial-cell death
myocardial infarction:
right ventricular
can be reduced with agents such as
oxide and with techniques such as induced alkalemia.
known
Pimrathoracic-
resistance: the resistance to blood
flow through the pulmonary circuit.
commonly caused by
due
to
membrane's
ability to
block protein migration
from the vascular space into the
interstitial space.
right ventricular afterload: Sec
pulmonarj vascular
occlusion or spasm
of a coronary artery.
resis-
tance.
negative inotrope: an agent that causes reduced myocardial
inotropic state or contractility and. therefore, the lorce of
myocardial contraction
—
eg. propanolol.
serum bicarbonate (HCO3): reported in niEq/L (mmol/L).
The most ubiquitous buffer base in blood: binds with hydrogen ions
nitric oxide
(NO):
a nonpolar,
to
produce water and CO:, causing alkalosis.
low-molecular-weight gas
room and body temperature) that is highly lipid soluble
endogenous form, endothelium-derived relaxing factor,
has been shown to be the active agent in vascular smooth
(at
Starling's forces: the balancing act between hydrostatic pres-
its
sure (promoting movement
muscle relaxation. In
pressure (promoting movement into the capillary), named
Stalling after the scientist who first described the phenomenon.
for inhalation,
it
ing patients with
its
exogenous form.
NO gas available
has been found clinically useful
in treat-
pulmonary hypertension because of its
relax-
smooth muscle, presumably by lowcalcium levels. However, use of NO
ing effect on vascular
ering intracellular
remains experimental.
in to the interstitiumi
and osmotic
At the arteriolar end of the capillary bed. hydrostatic pressure
is
higher than osmotic pressure:
the venuku' end, the reverse
at
is true.
thoracic
pump augmentation:
an intervention designed to
counteract the effects of positive-pressure ventilation on
oxygen consumption
by the tissues
for
(
V(),): the rate
of oxygen use (L/min
aerobic metabolism.
ventricular preload. Large tidal
to
gen
in
(Ca()>): the
volume (mL) or mass
(g) of
left-
used
left
to
heart filling.
oxy-
transmyocardial pressure gradient: the pressure difference
blood
between
[1.34
is
compress the contents of the lung, forcing blood back
the left heart and increasing
oxygen content
\olume (15-20 niL/kg)
Hb(g) S,o;(%)] + [0.003g/torr-
Respiratory Care
•
February
'96
PaO:(torr)].
Vol
41
No
2
left-ventricular
and intrathoracic pressures. As long
as this gradient does not change, left \entricular contractile
131
Cardiorespiratory Interactions
force does not change,
ever
when
autoreguiated
tic
in
arch.
A
and cardiac output
is
maintained.
How-
intrathoracic pressure increases, aortic pressure
down by
is
stimulation of baioreceptors in the aor-
may
tion
actually be due to reduced venous return and right
ventricular preload. If right-heiirt output
output
is
is
reduced, left-heart
also reduced.
persistent increase in intrathoracic pressure results
decreased left-ventricular afterload increasing contractile
West zones: A model used
tion of
force and cardiac output.
blood flow
the capillaries. In
ventricular interdependence: The right and
do not function independently.
preload that occurs
in
left
ventricles
TTie reduction in left ventricuhir
response to positive-pressure ventila-
(Pa)
>
2. the
Pa
arterial
in
uneven
to explain the
distribu-
the lung based on pressures affecting
Zone
the lung apices, alveolar pressure
1.
pressure (Pa) > venous pressure (Pv). In
mid-lung regions.
P;,
> Pa >
Px
.
In
Zone
3.
Zone
the lung bases.
> Pv > Pa-
Jidlr7i^Wryj
CARE
Special Issues
Mechanical Ventilation;
Ventilatory Techniques, Pharmacology,
&
Patient
Management
Part 1: April
Part 2:
Strategies
1996
May 1996
RESPIRATOR'!
Care
•
February
"96
Vol
41
No
2
Nole
to publishers:
Send review copies of books,
Respiratory Care,
Phamiacolog) for Respiratory Care Practitioners,
GP
by
HB
and
Cottrell
Surkin.
FA
Hardcover, 414 pages. Philadelphia:
Davis Co. 1995. $36.
Books, Films,
Tapes, & Software
and Reviews of Books and Other Media
Listing
lilnis. lapcs.
1030 Abies Lane. Dallas
1
concepts of
and software
TX
to
75229-4593.
halt-lilc. clearance,
ability are treated descriptively.
and bioavail-
tral
The
ters
sections
agents, antiarrhythmics, antithrombotics,
without resort to the underlying chemical
thrombolytics. Although these chapters are
The third chapter, on
is more scientifically
provide sufficient introductory knowledge
pharmacodynamics,
because the clinical practitioner must
detailed, illustrating drug-receptor interac-
the
major medical
inter-
specialties.
comprehensive than those
in
designed for the program
cology and outlines the form and varieties
account of the drugs employed
curriculum. The selection of topics and the
of neurons and the principles of synaptic
try
expository detail arc always limited by the
transmission.
texts
time constraints of the course of instruction.
The ensuing chapters describe
the structure of the
many
intensive care units.
Unit 2 follows the conventional sequence
of most of the standard works on pharma-
pharmacology
3. tliey
to enable the practitioner to understand
problem forever confronting authors of
a
Unit
and
of the conditions that confine patients to
and dose-response relationships.
tions
less
How far to go beyond purely respirators' drags
is
anti-
cribe the roles of each participating organ,
principles involved.
all
4 compnses b chap-
anginal drugs, diuretics, antihypertensive
respiratory care edu-
face with
Lliiil
on inotropic agents (cardiotonics),
on biotransformation and elimination des-
cation have always been difficult to define,
The boundaries of
nenous system.
autonomic nervous sys-
Unit 5 gives a surprisingly complete
psychia-
in
and anesthesiology. Chapter 24
is
a
review of sedative-hypnotic, anxiolytic, and
antipsychotic agents. Chapter
2.5
deals with
have encom-
tem, the principal neurotransmitters in-
analgesics and the
management of pain; and
passed a rather broad spectrum of topics that
volved, and their respective roles at ganglia
the next chapters.
26 and 27, discuss
The authors of
is
this text
intended to correlate with the other basic
sciences of the respiratory care curriculum.
was
Prior to publication, the manuscript
reviewed by a number of competent educators
—
their approval constitutes
its
glance the text
first
sites.
The
actions of
acetylcholine (nicotinic and muscarinic) are
emphasized; adrenergic transmission
sidered
one proof
of the appropriateness of the book for
intended purpose. At
and neuroeffector
more
Unit 3
tifying the
titioners.
is
con-
is
book
as a text for respirators' prac-
first
chapter of the unit (Chap-
comprehensive discussion
ter 9) is a rather
age 2-year curriculum. However,
of allergy, although the immunochemical
it
is lib-
and (Kcasion;il vignettes, called
tables, charts,
Perspectives, that
and
promote general
clinical relevance.
rapid reader,
was able
interest
The reviewer,
to
not a
cover the written
portion in less than 30 hours.
The book
is
comprising 3
the
is
first
to 8 chapters.
The
first unit,
The Physiologic Basis of Drug
entitled
Action,
divided into 5 units, each
a review of general
pharmacology;
chapter deals with pharmaceutical
aspects of drug design, testing, and approval.
Because one of the authors
is
from Canada
and the other from the United
States, the
regulatory bodies of both countries are des-
introduction
on
is
bnef The discussion focuses
mechanisms of bronchospasm.
tlie
preamble
as a
to the
ku'gely
ensuing chapters on
drugs employed for the prevention and
treat-
is
nonmathematicah
solubility
the effects of
and absorbability
are simply given empirically. Similarly, the
RESPIRATORY CARE
•
FEBRUARY
"96
schedules of controlled drugs
in the
United
States and Canada.
The authors have made considerable
make the book as understandable
effort to
to the uninitiated reader as possible.
are the generic and trade
Not only
names of drugs
given, but the pronunciation of the generic
form
usually rendered in phonetic sym-
bacterial species, are also pro-
adrenergic agonists; and Chap-
nounced.
A
Chapter
ter
1
3,
1
2,
xanthine bronchodilators. Complete
is
Other
difficult
words, such as the
separate section showing the
symbols and abbreviations used
is
conve-
instructions on the administration of the drugs
niently presented at the beginning of the
each of these categories are given, pro-
book. Indexing and referencing are appro-
in
viding a valuable reference source for the
practitioner.
ter
The Unit then presents
a chap-
on glucocorticoids, a chapter on mucoki-
netic, surface-active,
and antitussive agents;
applicable to the treatment of bronchopul-
kinetics.
the second with prescription writing and the
names of
I.
antimicrobial and chemotherapeutic drugs
pH change on
first
antimuscarinic agents;
1
shown. The second chapter, on phannaco-
names of drugs
follow the text; the
deals with pharmaceutical calculations, and
tamines; Chapter
fer in the 2 countries these are explicitly
generic
a brief discussion of analeptic drugs
bols.
and, finally, 2 chapters are presented on
Where
local
Chapter
ment of asthma. Chapter 10 covers antiallergics (mast cell stabilizers) and antihis-
dif-
cribed.
is
final
used as respiratory stimulants.
Two appendices
appears to be formidably lengthy for the aver-
erally provided with excellent illustrations,
(28)
fully in the next unit.
really the definitive section, iden-
The
and general anesthetics. The
monary
The
focus upon drugs that
affect the cardiovascular
VOL
41
NO
2
the
book
is
Above
all,
quite readable, and should be
user-friendly to students of respiratory care
pharmacology and
to their instructors.
Hugh S Mathewson
MD
Professor Emeritus, Anesthesiology
Professor, Respiratory Care Education
disease.
last 2 units
priate for the content of the text.
system and
tlie
cen-
University of Kansas Medical Center
Kansas City. Kansas
133
)
Classic Reprints
Retrospectroscope
Out of the Mouth of Babes
member
is
to
be a talent
seotit
or his medical students
abilities
t'ac-
it
leaches him that numbers are beltei than guesses
when
delennine the special
it
comes
treat-
main ivsponsibiliiy of
I've alv\a\s belicscd thai a
ully
—
to
a
teaching.
in clinical care, in
or in research, and then to encourage them to be the very best
they can in their field of unusual competence.
course,
is
research.
I
see no
way
with research while they are
that
who
now
students
strongly that, as i)ne
I'm
who
lately has
stale,
know how
again as a recent patient, that I'm
place
Providing a
stiiilcnls
w
iih
it
him
But
t)f this later).
do
i(
also
makes
at
Hiimphn
it.
Let
faxnr
faculty
own
is
to
marked ;malgesic
and
40 years
ot the
to
still
hul w
in
effect.
Near the
eiui ol'.luly
1
its
799. Dav y wrote:
I
much
nil
alterwards returned.
it
less violence. In a .second instance,
a
headache was w holly rcmov ed by
gas.
The pow er of the immediate operation of
removing intense physical pain.
I
ihe gas
had a very good
opportunity of ascertaining.
In cutting
school's
cntkie.
continue their
1
one of the unkickv
teeth calletl denies sapi-
experienced an extensive inllammalion of the
gum, accompanied with great
tlown
pain,
which equally
destroyed the power of repose, and of consistent action.
when they must now judge for themselves what's
good and bad. what to adopt and what to shun. A little
blesome.
research also teaches the medical siudent the essentiality
The pain alw ay s diminished
of controlled studies, especially when he must esaluate new
inspirations.
It
when he prepared and
in Bristol
iiisiaiKc. when
hud headache from indiwas immediately removed by the elTecls of
two doses of
to look
after they've
it
slighter degree of
On
the nest,
modes of therapy.
to
a l9-ye;ir-old student in Dr. Bed-
a large dose of the gas. though
no course
is
one
gestion,
Lots of w ays.
There
encourage and teach students
scientific education for the
from early
inhaled large quantities of nitrous oxide and discovered
labeled "Critical F.\aluation of Data" in any medical school
catalogue and \ei the niosi important job
lh\\\ was
doe's "'Pneumatic Institution"
a better physi-
How ?
in journals.
that
being a patient
to read .scientitic articles critically
data published
is
give yt)u a few examples:
in
obiecti\ely
of course ask. "Where's the
immediate pay-off?" The answer
modern times, some very remarkable discoveries have been
made by youngsters who were still medical students. Let me
helps to identify those
research.
as a device to recruit researchers but as
Some congressmen would
direct,
of research experience for medical
Of course
— not
produce better future physicians.
a device to
and out
who gen-
unusual originality and unusual talents for a career
teaches
experiments
In
little bit
helps both ways.
research (more
I
I
1
cian of i)ne with no desire to
It
in
e(.|ually in
me IVom
If
research (laboratory or clinical) for cook-book laboratory
I
opt for
go about
to
w ere dean of a medical school and had complete
dictatorial powers.
would substitute some months of
ment.
state pretty
been a patient
of research that wDuld ha\c presented
in the first
Now
So before
favor of doctors (and nurses)
all in
uinely care for sick people and
me also
me
a letter of protest to the Editor, let
ol hospitals.
contact
that students be
research and loo few for taking care of sick people.
you write
of
of anguish from those
call forth cries
many medical
believe that too
some
medical school.
still in
even a whispered suggestion
involved in research will
field,
for faculty to determine this
special talent of their students unless they have
know
One
and evaluation of
to diagnosis, prognosis,
the
1
day when the intlamniation was most troubreathed three large doses of nitrous oxide.
(
after (he first four or five
I
teaches him a systematic approach to
problem-solving, and once
in practice, he'll realize that
almost every patient presents a new problem
lo
him. .And
La(cr. in the Conclusictn to Section
w
rote. ".As nitrous
oxide
in its
111
ol the
same work. Davy
extensive operation appears
capable of destroy ing physical pain,
it
may probably be used
in w hich no great
with adv anlage during surgical operations
Reprinted wiih permissidii
Rev RespirDis 1476:1
134
14:
(it
tlic
AniL-ncan Lung Association, from .Xni
lOOI-KKW.
effusion of blood takes place." Gibson (2) surmised. "Unfortunately no one read as far as page
fi5(^.
Respiratory Care • February
or understood this
'96
Vol
41
No
2
.
:
Retrospectroscope
By companng
proclamation of the surgical anesthetic value of nitrous oxide."
for
\
it
was
not until
1
844
that
Wells
America put
in
same
this obser-
William Morton, although alread\ practicing dentistr\
It was in 1846 (as a medhe demonstrated the
ical student-dentist) that
as a surgical anesthetic agent (3. 4
use of ether
first
him. '"You will be free of pain during
this
operation because
.
even
about Morton speaks
article
Eugene Landis.
did his direct
(
since then:
was not
but did teach chemistrv
.)
the medical department of Har\ ard betw een
Morton
been able
Of equal
as a graduate.
to
confirm
that
interest
1
is
845-86 do not
that
no one has
he received a dental degree
at
the
Baltimore College of Dental Surgery (now the University
of Maryland), or even matriculated there, although he did
study dentistry
in
necticut. (Wells
Horace Well's office
was
in
Farmington. Con-
the first to use nitrous oxide for pro-
in practically
to
the "islets of
is in
be the source of insulin)
in
nerves and another on
tactile
for ten
J.-L.-M. Poiseuille de\ised the mercury manometer for
measuring arterial blood pressure w hen he was only 29 years
a medical
intra-arterial pressure starting with the ascending aorta
which he could
and
insert a
ending with the smallest
arterv into
cannula and proved that
intra-aiterial pressure fell but little
in
these main conduits. Some years
measurements on resistance
lished Poiseuille's
Law
to
flow
later,
in
he did his classic
small tubes and estab-
still
later
cells (later
disco\ered
1868 while he was a medical
Before
(9).
this
important
corpuscles in the skin.
Charles Best w as a medical student at the University of
Toronto when Banting wheedled the use of a laboratory from
summer of 92 Banting also asked
assistant. The assistant assigned
1
1
.
dogs and a research
student Best. Within several
Best had discovered insulin
still
(
months Banting and
10).
Jay McLean had been accepted by Johns Hopkins Medical
School as a second year student but had
to wait a year
before he could be admitted. During that year, he did research
in
Professor William Howell's physiolog> department "to deter-
mine
if
I
could solve a problem by myself."
covered heparin
(
1
1).
to the
amazement and
professor, a longtime leader in research
He
did.
successful
first
continuous recording of
arterial
method
in
1950 but
the artery
to
(7).
ity in
through
w hen the needle is withdrawn.
this
mits recording for long periods of time
w itliout discomfort
technique per-
relatively free mobilit\ of the subject.
record, received
work using
and
in
Attached to a capacitance manometer,
and allows
the \ear after Roentgen's disco\ery of x-rays.
man
A small plastic catheter, inserted into an aner\
is left in
in
for accurate
blood pressure
stated:
a needle,
The
the
new technique
1
896,
to stud>' gastrointestinal motil-
1897: his classic paper on the influence of emotions
in
May
on
gastric motility
was published a year
later
( 1
2a). Incidentally,
another medical student. Albert Moser. worked with
that
same year on esophageal
motility
(
12b).
He
Cannon
died of tuber-
culosis only five years later.
by an ink-writing oscillograph, permits
an opportunin.' for observation of any chiuiges
tour of the pulse
is
in
He at once went
conscious animals by giving them barium to sw allow
and studying gastric contractions by roentgenogram. He gave
his first account before the American Ph\ siological Society
continuous knowledge of blood pressure and provides
ratus
dis-
on blood coagulation.
Walter Cannon entered Har\ ard Medical School
He
He
disbelief of his
(6).
Lysle Peterson received his M.D. degree
1949 published the
site
discovery, he had already published one study of cutaneous
w as medical
he measured
original
the arterioles.
student at the University of Berlin
degrees
student (5). In addition,
its
every textbook of physiology
Langerhans" and
Professor Macleod for the
in both.
the University
at
Paul Langerhans found the special pancreatic
named
Harvard,
and venu-
demonstrates unequivocally that the main
it
ducing anesthesia.) Although Morton never earned a degree
in either medicine or dentistry, he later received honorary
old and
used
1922-26). Figure 7 from his report, received
of resistance to blood tlow
listed as a regular
But the records of
at
arteriolar, capillary,
for publication in 1925 (8). has been reprinted in
However, the Catalogue of Students Attending
Medical Lectures at Har\ ard Uni\ ersity in Boston 845-46
does list "Morton" William Thomas Green. Boston; Charles
1
Professor of Physiology
blood pressure while a medical student
lar
of him as a dentist and only a few mention that he w as a medical student.
later
measurements on
or modified fomi
T. Jackson, lecturer." (Jackson
now
is
universalh in intensive care units and reco\ery rooms.
of Pennsylvania
of discoveries by two medical students."
IncidentalK practically
This method, as modified by Seldinger and others,
as a reminder of
So
1.
Humphrv Davy and of William Morton, as each congressman
is wheeled into an operating room for w hate\ er. I would infomi
list
in the
constriction. or distensibilitv of the arterial system.
entered Harvard for medical training.
member
w a\'es
infomiation concerning changes in stroke volume, \aso-
ation to practical use.
facult\
the contour of the pulse
subject under different conditions, one can obtain
in the
con-
w ave which may de\ elop. The appa-
compact, mobile, and
Respiratory Care
•
'96
Vol
his first paper in 1920. a year before
he received his B.S. degree and a Rhodes Scholarship. Between
then and the end of 1927 (when he received his
flexible.
February
John Fulton w rote
41
No
M.D.
degree).
135
Retrospectroscope
he had 40 publications.
644-page mono-
iiicJLiding his classic
graph. "Muscular Contraction and the Reflex Control of
Movement." published
in
926
1
in
1878. In 1877, he discovered the parathyroid glands; he
wrote, in part:
(13).
.About three years ago
Josef Breuer began
and completed
One of his
medical training
his
requirements tor qualification
his
clinical teachers offered
him an
age 25.
at
in
Hering's physiology laboratory.
14) and presented his
(
work
Vienna Academy of Science. Shortly
the
tound on the thy-
I
tive tissue capsule as the thyroid, but
assistantship that
examination revealed an organ of a
That year Breuer discovered the Hering-Breuer (or Breuerrefle.x
1877|
could be dis-
tinguished therefrom b\ a lighter color.
allowed him time to work
Hering)
1
dog a small organ, hardly as big as a
hemp seed, which was enclosed in the same connec-
roid gland of a
the age of 17
at
early in
868
1
thereafter,
from
structure
to
vascularity.
Breuer
gland
in
superficial
and with a very
that of the thyroid,
The existence of a
...
A
totally different
rich
unknown
hitherto
animals that have so often been a subject
ot
entered the private practice of medicine but found time for
anatomical examination called for a thorough approach
research on the semicircular canals. Yet Breuer's greatest
to the region
in
man.
achievement was
Although the probability of finding something
hith-
to lay the
groundwork
for Freud's study of
around the thyroid gland even
erto unrecognized
psychoanalysis. Breuer's biographer wrote:
seemed so small
that
was exclu-
it
sively with the purpose of completing the investiga-
Bclwccii IXSOiiiui
Miss
ical patient.
I
physician
h) pnosis.
in
it
tions rather than with the
this
famous
therapeutic use of
in this ease.
Pnx'eeding entirely
sides at the intenor border of the thyroid gland an organ
to
i)l
He had been
I
the
I
of the size of a small pea, which, judging from
empirically. Breuer and his patient discovered with sur-
symptom wduld disappear and
prise that a
if
in
rior,
ne\ er return
sory thyroid gland,
which the symptom had appeared
for the first time
showed
on
that occasion.
nations not onlv
for the procedure
was "talking
its
to give expression to her feelings
The
patient's
name
cure." Breuer later termed
Breuer fast met Freud
enties.
.
.
.
Despite
m
.
.
.
did not hear about the case of Miss
treatment had ended
in
1
882.
It
was
I
1
was
convinced of the constancy oi
also able to
show
most eases occur on each
in
that tw
side.
{
o such
17)
the late eiglueen-sev-
friendship at the time Freud
tlieir clo.se
exte-
exami-
a rather [leculiar stmcture. .M'ter several
appearance but
glands
"catharsis."
it
its
lymph gland, nor an accesand upon histological examination
did not appear to be a
he eould bring her to relate the exact circumstances
and
hope of finding something
make
Vienna
and he used
hyster-
new that began a careful examination of this region.
So much the greater was my astonishment therefore
when In ihe first indi\ idual examined found on both
His handling
,'\nnu ().
ease started a seientille revolution.
lirst
;i
Breuer treated
}sS2
tixik
Anna O.
Paul Ehrlich's
until the
a
Freud anollicr twelve
first
paper, publishcii in
1
877 when he was
medical student aged 23. had tremendous impact on the new
science of bacteriology since his was the fwsi analytic study
years to persuade Breuer to publish a detailed report of
the ease.
of staining methods (18). In
But he [Breuer] was aware of what he had
Towards
end of his CurrUuluin he
the
tourth edition last year. For Freud
it
on
started.
says: 'This
was
the seed
from which psychoanalysis grew." (15)
Maurice Raynaud
of
s_\
name
him
in
862
1
first
(16).
the
He was
that
s>
now
ndrome
bears his
then a medical student and his thesis
M.D. degree. He wrote,
Under the
the height
in part,
won
about his patient:
en moderate cold, and even
of summer, she sees her fingers become
intluence ot
low colour.
.
.
.
more impressionable even than
Tlie feet,
the hiinds. are regukuly attacketl at meal limes
is
going on.
.
.
.
and whilst
The complete disappearance
of attacks of local syncope has always been noted by
this
1878 thesis based
lady as the
first
index of a
commencing pregnancy.
practice of technical dyeing might well be expected to
from a correct theory. Sir Henry Dale has commented
it
are alreadv
logical problems,
even
gemis of some of the
tlie
136
of Uppsala
in
at
the Univer-
1872 and received his preclinical degree
detailed
conceptions, which were so largely to dominale
ways of thought and plans forexperlmenl.
Ehrlich's
all
the rest of his scientific career.
Ehrlich's immediate and most direct application, of
the interests and the principles
so preeivlouslv
iiig
ot the
in this Tliesis.
w hich he had dev eloped
w as to
the dilferential sl;un-
white cells of the bl(K)d and the tissues, show-
ing that the granules in
tlie
protoplasm of diflerent types
could he recognized as oxyphile. basophile or neutKiphile.
according lo their respective
the linclonal
vv
Ivar Sandstrom entered medical school
and bio-
the lines of the theoretical approach to medical
components
vv
affinities tor dves.
of which
ere acidic or basic in nature,
or combinations of both. In these studies, and
sity
little
improvements
result
v
ex-sanguine, completely insensible, and of a whitish yel-
digestion
in his
in the
during
at
and
he criticized the histologists because they cared
that in
described the
mmctncal ischemia of the extremities
it,
for the thfoiy of staining despite the fact that
book
appeared
v\as at first rather unfa\ ourabh' received, but
in its
it,
...
in
others
hich he made, in this early peritxl. on the nature of the
red blood corpuscles and their pathological variations,
can be found the basis for a large
Respiratory Care
•
part ot iiKxIeni
haema-
February "% Vol
41
No
2
.
Retrospectroscope
of the kidney, for then you
toiogy. Clear descriptions will he found, for example,
in the
earh date, of the presence,
at this
tain cases
of anaemia, of immature red
also see this
from the renal ducts severed
of tlie type
may
clearly observe
cells,
its
quality
same juice
way and you
and nature. You may
arise
in this
much more easily if >'oii apply a glass lens
to your eye for then, when the tubules are compressed,
observ e this
recent years as "reticulocytes", and
more
so familiar in
may
hlood from cer-
of their characteristic staining with certain dyes. (19)
the urine
is
very clearly seen welling out as
if
gush-
many little water pipes.
things we can confidently infer that
ing forth from so
But
let"
far
—
more important
v\
as the concept of the
"magic bul-
From
on
to specific receptors
of Salvarsan and of
cells
—
these
the
substance of the kidney, even thiiugh they have called
chemicals could be synthesized to attach
that specific
the basis for his later discover)
parenchyma,
it
ulae and
much of modern chemotherapy.
nothing else than
is
capillar.'
into the pelvis.
a
...
mass of canalic-
spaces through which the urine flows
...
Adam
in the
Thebesius undoubtedly discovered the channels
ities of the heart w ith the coronar\' vessels
nnocardium (20). connections kntmn toda) as Thebe-
sian
essels.
connecting the ca\
\
and undoubtedly he discovered them while he
two
From medical
student to professor!
The next
year, at age
20. Bellini was appointed professor of philosophy and theoretical
medicine
at Pisa.
a medical student at Leyden. Tlie fact that Vieussens.
was
ities
into the cardiac cav-
same openings
years earlier, found the
does not diminish the value of Thebesius' s careful injecVieussens and Ttiebesius found the
tion techniques, .^ctually.
same small openings connected
although Vieussens perfonned
to the
coronary circulation.
for\\ aid injections throtigh the
coronar\ arteries, and Thebesius performed retrograde injec-
and \eins.
tions tlirough the coronary sinus
Thomas Young,
one of the most eminent of British
entists, solved the riddle of visual
vear-old medical student: a year later he
was elected
sci-
a 20-
accommodation while
a Fel-
London to honor this achieveknew that vision could be sharp
Young
before
ment. Scientists
looking at a near or far object.
was
person
whether
a
and clear
the eyeball itself shortened
was
that
explanation
favorite
The
low of the Royal
.Society of
or lengthened and so appropriately changed the distance
his medical studies in
Joseph Black began
versity of
Glasgow and concunently began
of alkalies then
in
1
744
at
the Uni-
his investigation
between the lens and the
that the intracxrular ciliary
showed
instead
Edinburgh where
ness of the ciliary muscle effected a thinning or thickening
which culminated
mo\ed
to
On heating
limestone or chalk. Black
(who belie\ed in ucivliin.ii things and not merely observing)
found it became lighter, presumably because it lost "air": limestone lost an cqui\alent amount of air when added acid caused
effervescence. But the gas relea.sed was nut air because it extinguished both flame and
of the lens, which had elastic properties.
discovery of CO: and the beginning
ni the
of quantitati\e chemistry.
life
(originally discovered in
(21
).
Black had rediscovered
CO:
1662 by Van Helmont) and begun
the "chemical revolution" of the
1
Paul Bert
Bellini.
1
9
\
changed the standard picture of the kidney from a hard, solid,
found
is
\
1
.
1
78-page volume, "La
best
known
in
France he
for his
1
the specialty of skin grafting during the
uary in the Lcincct (November 20,
work on high
altitude
1
war of 1870. His
obit-
886) speaks only of his
fails to
mention his defini-
hypoxia and hyperbaric environ-
ments, or even that he w as a great physiologist (25)!
esting that Bert himself did not regiu-d his studies
It is
inter-
on skin
graft-
ing as experimental surgery but as a technique for learning
that
otherwise, tor the substance ot
nothing else than an aggregate of an
is
number of
for his
work on skin grafting, which he published in 863 while he was a saident in medicine and an assistant to Claude Bernard (24): it was responsible for fostering
was
how
the state of affairs
famous today
pioneer work on skin grafting and
8th centur\
ears old and a medical suident at Pisa,
fleshly organ (22). Bellini
is
Pression Barometrique." but during his lifetime
tive
nite
(23)
stimulation) or relaxed (with none) and the change in thick-
he took additional medical courses and continued his research.
the kidne\ s
Young
use for treating patients with stones in the
kidne\ and bladder. In 1752 he
Lorenzo
retina.
muscles contracted (because of nerve
essels of a kind peculiar to
itself.
infi-
Hav-
ing cut through any part of the kidney, certain fibres
in a
transplanted tissues live in a
new environment.
It
was
sense a stepping stone from his Professor's study on the
internal
environment to Bert's
later studies
on
how chang-
ing the external environment (high and low pressures and high
and low oxygen tensions) affects body function.
or filaments extending from the outer surface to the
hollow or pehis are quite plainh visible
If therefore
further end. that
ine them,
If
you
w ill
you
is.
discover a certain saltiness and
'>'ou
can
Respiratory C.\re
their
with respect to the pelvis, and exam-
will find water welling
are not afraid to present this to
of urine.
...
you compress these filaments from
test this
•
also
if
up evei^where.
your tongue, you
in
some
vou cut across
February
Martin Flack had just completed his preclinical work at
Oxfoid w hen he became involved in the search for the sinoauricular node (26). As Gibson (27) relates the story;
'96
Vol
the taste
the
41
body
No
2
The village of Borden [in Kent, where Flack lived]
was agoa when in 1903 the celebrated anatomist Sir
137
;
Retrospectroscope
Arthur Koith took up week-end residence there. With
exceptional stability
some
such low power requirement that
sixth sense he learned that the butcher's
boy
work at
[Flack] had just completed his preclinical
Oxford and was about
in
London
pital
of a reflector and smooth control of
London Hos-
and scheduled for week-end research
in
may be
operated
High illuminating efficiency obtained by
for his clinical studies. In a twinklinj; the
student found himself admitted to the
it
by a storage battery.
teaching hospital
to select a
secured by using a lamp of
is
wide range permit the use of color
a
Borden
the use
light intensity
over
of very
fillers
high selectivity, thus greatly extending the scope of
with Keith.
the apparatus.
Tlie dnidgerv' of cutting serial sections of 1.^0 moles'
.
.
simplicity
.
and convenience of operation have been
and studying them under the
improved by using standard
microscope was relieved by daily games of golf, learned
ventional absorption cells.
hearts, staining them,
from James Braid's manual. One evening
Complete mechanical
Sir Arthur
came back from cycling to be told by Flack that be had
spotted a new structure in the right auricle. It appeared
consistently in
all
parts,
and
test-lubes in place of con-
rigidity,
absence of moving
a large safety factor in all
important com-
ponents eliminate the usual causes of unsatisfactory
other hearts examined as something
performance.
resembling an electrical conducting system. Thus was
discovered
tlie
known
[also
sinoauricular node or ciirdiac
pacemaker
William MacCallum and Eugene Opie were members
first class of the Johns Hopkins University School of
Medicine, which entered in 1893 and was graduated in 1897.
as the Keith-Flack node].
of the
Jan
Swammerdam
objects floating in
floaters as
he was
was not
blood corpuscles, probably
still
if
first
and
to recognize these
year 1665 while
in the
Harvey had
a medical student (28).
the presence of capillaries
cle,
the first to see capillaiies
them but he was the
to postulate
blood really went art)und
in a cir-
because he never saw them. Malpighi, with the aid of a
microscope, described pulmon;iry capillaiies
Malpighi also saw bodies floating
to be fat globules.
Swammerdam.
in
in a frog in
1661
them but believed them
hovve\'er. identified
them
as red blood cells:
While
to
(
medical students, they
still
knowledge of piu-asitic
30, 3
1 ).
scientists in
Of the
a scourge at that time.
men were
78,000
in
1
880
some birds
hematozoan. Malaria was still
1885 had found
harbored a similar parasite, a
1
important contributions
Laveran had discovered the makirial parasite
and European
of
made
infections of red blood cells of birds
British
Army
that
in India,
76,000
admitted to hospitals for malarial fever
in 1897: there were 15,000 deaths annually in Italy, and there
was much malaria in the United States. Knowledge of the life
in man was incomplete and the theory
was transmitted by a mosquito was only a
was not until 1897 that Ross found, in the stom-
cycle of the parasite
that the parasite
I
saw
a
serum
in ihe
nuniberof orbicular
blood,
in
particles, in
which were
shape
but very regular. These particles also
tain another fluid, but
a vast
conjecture.
like flat ovals,
seemed
to con-
the blood.
1
further
observed that the more these objects were magnified
first
discovery as a medical student.
year earlier he had discovered the valves
sels
if
and
in
1667 he discmered
in
that the lungs
A
lymphatic ves-
of newborn
discovery of MacCallum.
that
Nkrnson had thought the motile
ellated spores; that
Kenneth P3velyn. more than two years before he received
M.U. degree at McGill University, devised a photo-
electric colorimeter that at least for several
decades was
its type. In 1936 anyone who was
pulmonary research and was lucky enough to have a little money bought a spirometer, a Van Slyke manometric
apparatus, and an Evelyn photoelectric colorimeter: if he
the best instrutnent of
in
third of these, he
oratory bench to use
Evelyn suinmari/ed
138
had a stream of
visitors to his lab-
it.
its
In
in his
1936 paper (29);
will be
and impor-
remembered
be flag-
fikuiients to
had studied them much without
filaments.
kinds,
Working with
first that
the
Hulwridium of birds he
seemed to be of two
the gametocytes
namely one kind which produced
the motile
aments, and another kind which did not do
watching two of these
field
...
1897 MacCallum undertook a study of the motile
cells,
one of each kind
so.
in the
fil-
On
same
of the microscope, he observed (July 1897) that
the filaments escaped from one as usual; that
it
moved
about actively for a lime; and then approaching the other
gamelocyte actually entered
it.
Other observations of
MacCallum and Opie, made both on Halteridium and
on the crescentic gametocytes of the aeslivo-autumnal parasite
advantages
I
It
being able to learn anything new about them.
noticed
had the
be able to begin this part of the nar-
tant
lloat
respiration has already occurred before death.
his
to
rative with a brief account of the brilliant
become.
This was not his
his
am happy
I
with a microscope, the fainter their colour appeared
to
malarial parasite, and he continued
work on malarial parasites in birds.
Ross, in his Nobel lecture on researches on malaria, delivered December 12. 1902. wrote:
and confirmed
ures also, according as they were turned about in var-
scrum of
human
ary stage of the
when I viewed them sideways
they resembled crystalline clubs, and several other fig-
ious directions in the
It
ach of a mosquito, bodies that were probably an evolution-
er)
.
The
of man, confirmed
fact, as pre\ iously
Respiratory Care
•
this beautiful
shown by
discov-
.Sacharoff that
February
"96
Vol
41
No
2
Retrospectroscope
the filaments contain chromatin
was now explained:
mo\e about
and also the tacts that they escape and
They
the blood.
are. indeed,
character of a
in
warm"
sperms which are emit-
by
ted from the one kind of gametocytcs. the males, and
which
fertilize the
More
than
the
first
of
w hich w as
m
but
How-
XIV. peifomied
man
in Paiis.
mid-June 1667 (and probably the
was exonerated.
ter
elongated and vigorous, and moves
transfusion.
Moi'eau"
across the field
This motile form had apparently long been
first
In 1667
was uied
Lamy
for
manslaugh-
wrote a "Letter to M.
(published in 1668) excoriating the practice of
(3.3)
Lamy
cautioned against diseases produced by
warned of the danger of coagulation. His letter influenced Moreau and the newly formed
Academic des Sciences to forbid transfusion in Paris w ithimpurities in the blood and
seen by Danilewski and had been called by him a ver-
02)
inicidc.
in
died from a Uansfusion reaction. Denis
the case
of Halteridiiim of the crow that the female cell,
motionless before fertilization, afterwards becomes
in vitro.
17th centuiy).
recorded transfusion of animal bUxxl to man). His fourth patient
MacCallum obser\ed
this.
in the
four transfusions of blood from sheep or calf to
of the highest animals.
like that
deeply rooted
still
ha\'e
and a fomi of sexual reproduction precisely
their sexes,
blood was
ever. Jean-Baptiste Denis, physician to Louis
other kind, the females. Thus these
minute parasites, among the lowest of creatures.
his
whose brain was considered "a little too
man's personality was detertnined
tiian
(the concept that a
out permission (36); a few years later the French Parliament
Some
years
later.
Ross (then
Sir
Ronald) said about
discovei7 by two young medical students:
disgraced as a
felt
man
"I
this
have ever since
of scieiicel" (for Ross had erroneously
inteipreted the spenii cell vviiggling into the penetrated female
spore trying to escape /w;;;
cell as a tlagellated
it!) (.^3)
prohibited transfusion of blood to
fusion and
Alfred Vogl was a third-year medical student when, in
girl with congenital syphilis and
juvenile tabes was admitted to the
Vienna. His chief asked Vogl to
Wenckebach
itiject
1
Clinic in
ml of salicylate of
mercury (an antisyphilitic drug) every other dav. By chance.
army surgeon, brushing up on civilian
a retired Austrian
medicine, told Vogl.
morning;
it's
you can use
received this sample
"I
in the
mail this
a mercurial antisyphilitic. Novasurol.
He did.
it."
Maybe
FoUunately. the nurses of the Wencke-
bach Clinic collected urine daily and regularly measured and
charted its Nokniie. The patient's urine volume went from .'iOO
to
1
.2()()
later
to
1
.400 to 2.000
when Vogl began
ap[5eiued on the chart
tnl
on consecutive days: four days
the injections again,
t)f
mine volumes
(34).
tall
columns again
Vogl then injected
Novasurol into a patient with advanced congestive heart
whom
mea-
ger mine output. Within 24 hours the patient had minated
more
than 10
surol
customary diuretics
liters!
was
the
And
first)
put an end to blood
knowledge of blood groups and incompatibil-
the essential
of blood from two sources did not surface until
1
900. and
a safe anticoagulant was not available until 1914.
Rowland was a medical student when Roentgen discov-
ered x-rays in
December
able prescience and
1895. Obviously one with remark-
he founded the Archives of Clin-
initiative,
ical Skiaiinipln in 1896. "a series of collotype illustrations with
new photog-
desciiptive text, illustrative applications of the
raphy to
ber
is
Medicine and Surgery." The preface
dated April
2.
1
896;
in
expressed the hope that the
manent place
of
Medical
in
Skiagraphy
gen Ray
in
in July
1
to the first
num-
Sydney Rowland. B.A Camb.,
it.
new
publication "might take a per-
literature."
It
became
the Archives
April 1897. then ihe Archives of the Roent-
897. edited by
W.
S.
Hedley and Sydney Row-
land. M.A.. M.R.C.S.. and eventually the British Journal of
Radiology (192^).
Concluding Remarks
mercurial diuretics (of which Nova-
so.
was forbidden by Rome. This
fail-
failed to increase his
ure in
it
transfusion for almost 150 years and justifiably so. because
ity
1919. an emaciated young
human beings throughout
France. The Royal Society of England then deprecated trans-
were discovered: they lemained the most
I
believe that if without digging further,
as the
we
simply accept
immediate "pay-off" of medical student research the
effective diuretic until 1957.
discovei-y of carbon dioxide, ether, nitrous oxide, insulin, hep-
chlorothiazide.
arin,
mercurial diuretics, and the parathyroid glands; the proof
that
human
when Beyer came up with
You won't find the name of Vogl, the med-
ical student, on Saxl's 1920 paper, or on Saxl and Heilig's
1920
article,
but that
is
how
a so-so antisyphilitic diiig bccatne
etnotions can profoundly affect body function;
invention of the mercury
manometer
for
measuring blood pres-
sure; the concept that special chemicals specifically
a powerful diiuetic.
combine
with special components of cells (basic to most chemother-
Guillaume
Lamy and Sydney Rowland,
two other med-
apy); learning
ical students, had an itnportant intluence on tnedicine with-
inate malaria
out doing research.
somely. But
l.amy decided to study medicine
at
the Faculty of Paris
verted
some
how
—
to
go about skin grafting and how
we must add
a slightly delayed "pay-off:
brilliant career investigators.
transfused blood fioin a docile animal (a sheep) to change the
and treatment),
1
667.
Respiratory Care
•
February
'96
Vol 41 No
2
tic
who is
it
con-
hesitant medical school researchers into sure-fire,
Lower had performed the first transfusion of blood
from dog to dog in England in 1663 (reported in 1666 in the
Philosophical Transactions) and on November 23. 1667. had
about
to elim-
research by medical students has paid off hand-
willing to wait a
And. most important
little
he himself gets sick and wants the best there
a bit
to a skep-
longer for the "pay-off' (when
is
in diagnosis
of medical student research experience
139
.
Retrospectroscope
may
him with
well provide
3.
who early on le;uned
and know when
a physician
4.
new knowledge gained
human lives.
In 1970,
1
ready to save
is
letter
from a Swiss physician who had
the early I95()s.
in
I'ellow,
Med
Some
of your Re.search Fellows
may end up
in
pn-
may appear to
be
and the teaching expended on lliem
However,
lost.
my
although scientific thinking alone
advance the
is
that
enough
not
rigorous application
its
8.
medicine such as
9.
J.
1850, 43. 109-1
la
19.
Force du Coeur .\ortique. These
les
Recherches experimentales sur
CR
tubes de tres petiLs diamelres.
mouvement
le
Acad
Sci Paris.
C:
Peterson. L. H.. Dnpps. R. D.. and Risman. G.
method
for record-
ing the arterial pressure pulse and blood pressure in man.
Am Heart
.^
1949. J7. 771-782.
The capillary
Landis, E. M.:
pressure in frog mesentery as determined
Langerhans.
Am
Beitriige /ur
P.:
J
Physiol. 1926. 75. 548-570.
mikroskopischen Anatomic der
Bauchspeicheldriise, Inaugural Disserlalion. University of Berlin.
practice ver\ happily.
I
Surg
by micro-injection methods.
everyday
in
produced by
1846. 35. 309-317.
Paris. 1828.
Poiseuille. J.-I..-M.:
J.
to
of medicine, there will be no advance
art
without
at all
conviction
is
J.
1840. //, 961-967. 1041-1048.
7.
diti
I
Surg
Recherches sur
Poiseuille, J.-L.-M.:
des liquides dans
vate practice as
Med
Morton. W. T. G.: Comparative value of sulphuric ether and chlo-
No. 166. Didot.
6.
reads in part:
It
Insensibility during surgical operations
J.:
Boston
roform. Boston
5.
received a
been a research
laboratory research
in
Bigelow. H.
inhalation.
to read critically, evaluate data objectively,
1869.
10.
E.
Julius H. C'omroe, Jr.
I
wish
to
express
my
1
.
appreciation to Horace Dav-
enport for his account of Albert Moser: to Leroy
Vandam
for
Briti-sh
Columbia,
who has
at the
my
kindly called to
University of
1
2a.
in this
attention
12b.
some
young men and women,
.V
1
1
(2).
4.
5.
perfonned by young investigators because
by
who would
U..S. definitions.
I
decided to include
16.
today be considered medical students
This of course excluded
many young
and European physicians who had completed
all
British
1
able research leading to a thesis
excludes
all
of those
who did
Cobum. who wrote
8
monograph on rheumatic fever on the basis of observations made while he was a resident, and Carl Roller, who dis-
1
9.
Fulton.
20.
I
decided to include only truly out-
1
of decades; this means that
the
I
have not even delved into
work of thousands of medical student researchers since
NIH training grants pennitted many medical stu-
22.
summer
research experience or even a "drop-
J
Physiol.
B..
Am J Physiol.
1898.
means
studied by
359-382.
/.
and Moser. A.: The movements of the food
in the
434-1-14.
Muscular Contraction and the Reflex Control of Move-
Die Selbsleuerung der Alhmung dutch den Nervus vagus,
J.:
Akad Wissen Wien.
Ullmann.
About Hering and Breuer,
E.:
1868.
5.S.
in
909-937.
Breathing: Hering-Breuer
&
Porter, ed..
A. Churchill. London. 1970. pp. 3-15.
Raynaud. M.: De I'Asphyxie Locale
el
de
Gangrene Symetrique
la
Sandstnim.
Om en ny kiirtel hos menniskan iK-h aiskilliga diig-
V.:
1.
F.hrllch. P.:
Beitrage zur Kenntnis der .Anilinfarbungen und ihrer Ver-
u endung
der mikroskopischen Technik. .^rch Mikrosk Anat.
in
877,
1
263 -277.
Dale. H. H.: Introduction,
Himmelweit.
C:
Thebesius. A.
Corde.
Black.
J.:
ed.
in
The Collected Papers of Paul Ehrlich.
Pergamon. London. 1956.
Disputatio Medica Inauguralis de Circulo Sanguinis
Elzevier. Leyden. 1708.
.\.
Experiments upon Magnesia Alba. Ouicklime and some
Bellini. L.: Exercitalio
.Analomica de Stnictura
et
Usu Renum.
Stella.
Florence. 1662.
23.
Young.
T.:
Observations on vision. Philos Trans
R
.Soc
Lond.
1
793.
S3. 169-181.
24.
1950 when
dents to have a
rabbits.
other Alcaline Substances. William Creech. Edinburgh. 1796.
standing research done by medical students that has stood the
test
The movements of the stomach
//)«/..
J. F.:
Breuer.
in
2
intern). Further.
action of cephalin. .Am
Sil/ungsber
F.
covered the local anesthetic properties of cocaine while he
was an
B.:
Cannon. W.
/.i
his cla.s-
sic
and Noble.
.
gdjur. Upsala Lakaref Forh. 1880. /5. 441-471.
in
their research while serving as
interns or residents (such as Alvin
7.
requirements
some very remarkand an M.D. degree. It also
medicine and then engaged
R
des Exlremites Rignoux. Paris. 1862.
1
to practice
The thromboplastic
J.:
Cannon. W.
J.
only those
J
Centenary Symposium. Ciba Foundation Symposium. R.
have merely scratched the surface of biomedical research
I
J.
on normal
ment. Williams and Wilkins, Baltimore. 1926.
see references (27), (36), and especially Gibson's monograph,
"Young Endeavour"
McLean.
esophagus.
Retrospectroscope: for other
instances of research accomplished by
B.. MacletxI.
Physiol. 1922. 62. 162-176.
of the roentgen rays.
1
of the examples included
J.
effect of pancreatic extract (insulin)
1916. J/. 250-257.
verifying the academic status of Morton; and to William C.
Gibson. Professor of Medical History
C: The
Am J
I
Note:
Banting. F. G.. Best. C. H.. Collip.
Bert. P.:
De
la
Greffe Animale. No. 118. J.-B. Baillierc
el tils, Paris.
1863.
25.
Fulton.
J. F.:
cock and
out" vear.
F.
Foreword,
Buroniclric Pressure.
in Bert. P.:
A. Hiichcix'k. trans.. College
M. A. Hitch-
Book Co.. Columbus. Ohio.
1943.
26.
Keith.
.\..
and Flack. M.: The form and nature of the muscular con-
nections between the primary divisions of the
REFKRENCES
v
ertebrate heart. J .Anat
PhysioL 1907.-;/. 172-189.
27.
Davy'. H.: Researches.
Nitrous Oxide, or Dephlogisticatcd Nllrous Air.
J.
.lohnson.
London.
28.
W. C: Young Endeavor.
ical .Students
Contributions to Science b>
of the Past Four Centuries. Charles
tleld. Illinois, igss.
140
W. C:
Student discoveries
Svvammerdam.
pulmon:iry and cardiovascular
.\:\
and van der
.\:\.
Leyden. 1737-38. Vol.
II.
pp.
stabilized photoelectric colorimeter with light
fil-
832-833.
Med-
C Thomas. Spring-
in the
Biblia Naturae, sive Hisloria Insectorum. H. Boer-
J.:
haave. ed.. van der
1801).
Gibson.
Gibson,
systems. Chest. 1972. 6/. 283-286.
Chemical and Philosophical; Chiefly Conceming
29.
Evelyn. K, A.:
lers. J
Biol
A
Chem.
1936. 115. 63-75.
RESPIRATORY CARE
•
FEBRUARY
"96
VOL
41
NO
2
Retrospectroscope
30.
31.
MacCallum, W. C: Notes on the pathological changes m the organs of birds infected with haemocytozoa, J Exp Med, 1898, 3.
33.
103-116.
34.
Opie. E.
L.;
On
the
haemocytozoa of
birds,
J
Exp Med, 1898,
December
Physiology or Medicine. 1901-1921.
12,
Else\'ier,
1
J,
1974. 134, 330-345.
Am Heart
1950. jy, 1-4.
Lamy,
G.: Lettre a
M. Moreau
contre les prelendues utilites de
la
trans-
fusion, Paris. 1668.
902,
Ams-
Med J,
Vogl. A.: The discovery of the organic mercurial diuretics.
35
Ross. R.: Reseiirches on malana, Nobel lecture,
m Nobei Lectures.
and Opie, Johns Hopkins
J.
79-101.
32.
Harvey, A, M,: Medical students on the march; Brown, MacCallum
36
Gibson.
N
terdam, 1967, pp, 65-67,
Engl
W. C:
J
Student medical researchers and their contributions.
Med, 1961.
26-;.
802-810.
Call for Abstracts
1996 Respiratory Care Open Forum
Deadline: April 28,
1996
Accepted abstracts will be printed in the
October 1 996 issue of Respiratory Care
Selected authors will present
research
at the Open Forum during the
their
42"^^
International Convention in
AARC
San Diego. California
Respiratory Care
•
February '% Vol
41
No
2
141
-
Lellers addressing lop.cs „f curr™. inleresi or maieriai in
RESPIRATORY CARE
decline a letter or edit « ithout changing the author's views.
Cari:.
1(1.10 .'Vbles
1
Editor As Death Dealer
TX
Lane, Dallas
profession should
my time ;is an editor ot this Jourmy work except for one task.
loved
I
1
hated writing
often
1
of rejection to authors.
letters
a death dealer aiming
felt like
probably fragile ego. Thai one author
same way was revealed
uary 1996), \shen
"It felt like
1
at a
my
an airow ihrotigh
me
heart."
for hav-
flawed work had been published.
me
of an incident
occtiiTcd several years back
when
New
ing from San Francisco to
was Hy-
1
York. The
or so of our imprisonment lovingly engaged
with papers from his briefcase
them, talking to them, writing
At
last
began
it
1
was
dtill
mar-
he put the papers away. Then,
telling
himself as
— reading
in their
had not said a word
1
llie
me
to hiin,
he
about his work and about
To me
performer of that work.
sluH
— insurance or
the like
—and
did not encourage him. .After a long time
he slopped. Then, sensing the imbalance he
had created, he gave me
me the Great Ameiican
do
yr)/(
list
of procedures for which no scientific
member forms
me
my
chance, asking
Qiiesiion: ".Ami
whal
am
shy,
uncomfortable.
diffident, snobbish.
1
did not wish to say. "1
be asked
llie
polite,
in
way
a
I
tlid not w am to talk.
am an editor" and then
1
pro-fonna questions about
what an editor does,
etc.
How
could
1
reply
to staunch the flow of conversation
After a
moment
I
knew what
could identify an aspect of
ahead
(if
I
might have burst out laughing),
ly aiKl
dis-tinct-ly, "1
re-
am
NursSciQ
touch. J Holist
When
therapy.
to
1992:70(3.
8.
9.
1
said,
What few
quantitative studies have ei-
ther demonstrated
its
flaws'-'*''
1
1
2.
we cannot
Perhaps
we have
of the past and will reject
Clark MJ. Therapeutic touch:
is
Nurs Res 1984:33
Rosa.
L.'\.
I'herapeutic touch. Skeptic
994:(3) 1:40-49.
Rosa LA. Survey of "research" on
ther-
touch review committee, health
.sci-
unprm en
this plea to in-
Stahlman
modality'"^'" into res-
Therapeutic touch: fuzzy
J.
metaphysics
(letter).
Am J Nurs
199.');95
(7):I7-18.
'.'
piratory care.
4.
Scheiber B. University of Colorado report
1
Wayne C Anderson BA RRT
quirer,
1.5.
I
slow-
1
In-
994; 18(3 1:232-234.
Walike BC. Bruno
P,
Donaldson
S, Eret al.
lAjttetnpts to embellish a totally unsci-
Medical Center
a trained killer."
entific pnx.-ess with the aura
School of Respiratory Care
ter).
fiight,
Am
J
of science
(let-
Nurs 1975:75(8): 1275. 1278,
1292.
16.
RKKKRKNCES
Clanian H. Report of the chancellor's
committee on therapeutic touch. Denver:
University of Colorado Health .Sciences
River. C'alilorma
Krieger
I),
llic rcs[X)nsc ot in
\ ivii
Center, 1994.
human
henioglohin loan active healing therapy
Scientific Basis for
by
Therapeutic Touch?
on of hands.
direct laying
Human
Di-
A7v Haines responds:
inensions 1972;1:12-15.
2.
Xovember 199.^ issue of RespiRAIORY Care, a letter susiaests that our
of therapeutic touch. Skeptical
ickson R, Gihlin EC. Hanson RL.
Point Park College
I
142
P.
1994.
learned froin our mistakes
13.
corporate an
PJ?,*;:??
ences center, university of Colorado.
Loveland. CO: Front Range Skeptics.
piocedure with such weak underpinnings.
Jotirnal Editor. l')(iS-l99,^
In the
Clark
tic
re-
afford to support a
Phil Kitlredge
A
Am J Nurs
apeutic touch: a report to the therapeu-
Pittsburgh. Pennsylvania
iltle
Krieger D. Therapeutic touch: the im-
1
cannot be taken seriously.
days of cost containmcnl and
structuring,
Geron-
199.5;21(7):.34-4().
(l):37-41.
1
ineffectiveness'''' or
have had such serious methodologic
that the results
Inter-
(.'i):784-787.
attempts there have
St Francis
Silence reigned for the rest of the
I
Nurs
and the
Instructor
guy
l):89l-S96.
there a scientific basis.'
occupation
at the
Pan
primatur of nursing.
10.
at actual
Testing elec-
Snyder M. Egan EC. Burns KR.
tol
1
to do.
LXX.
iors in persons with dementia. J
be without merit.
been
1
ventions for decreasing agitation behav-
finally
truly bi/;uTe.'
(4):3 1 9-33
1
psyehokinetie effect of therapeutic touch
The literature supporting Therapeutic
Touch consists of anecdotal reports.' case
studies,'-' qualitative (?) research,-"'
1
on germinating corn seed. Psychol Rep
submitted to rigorous examination, they were
found
1
Geisi CR. Geophysical vari-
tromagnetic explanations for a possible
tojustify our u.se of such
were
AM.
field using therapeutic
Nurs 993:
ables and behavior:
the inability
Many of us believed
these procedures
Bush
7.
applications, IPPB.
was
post-
1993:6(21:69-78.
human energy
case reports and anecdotal evidence were
was needed
Nurs
France NE. The child's perception of the
6.
the poptilarity of these treatments
uate scientific research.
all llial
Holding sacred space: the nurse
JF.
operative pain: a Rogerian research study.
of matiy respiratoi^' care practitioners to eval-
that
I99.');9.'i(4):
Meehan TC. Therapeutic touch and
adtninistered
critical
my
had looked
some
(besides revenue generation)
without using the word "editor." .Staring
straight
we
of therapy
bottles, and, in
Am J Nurs
Pract 1992:6(41:26- ,16.
our hair
in
pressure (NEEP), ultrasonic nebulization.
blow
niixlalities:
as healing environment. Holistic
Those of us with gray
In these
iiiailc
Quinn
4.
basis can be found.
do?
This
inter-
Discover the healing power of
1.
therapeutic touch.
A factor in
thai
the next seat spent the first hour
although
part
26-3-3.
Some of these include Dale-Schwartz tubes,
CO: inhalations, negative end-expiratory
him from probable embaiTassment
gins.
opinion or
Mackey RB. Complenientan,
3.
opinion, this simply adds to a growing
had rejected 4 years
ing saved
in
The Editors may accept or
reflect the author's
my
despite a lack of evidence of their efficacy.
he went on to thank
All this reminds
provide Therapeutic
called the 'laying on of
from a
letter
Btit
fellow
may simply
5.
he wrote.
if his
published
hands')' as a form of 'holistic healing,' In
ihc
fell
early this ye;ir (Jan-
received a
1
person whose paper
ago.
will he considered fur publicalion.
letters as
75229-459.1.
Touch (formerly
Dtiriiiji
The content of
pretation of inlormation-not standard practice or the Journal's recommendation.
Authors of cniicized material will have the opportunity to
reply in print. .\<> anonymous letters can be published. Type letter
douhle-spaced, mark it "For Publicalion." and mail it to RESPIRATORY
Letters
nal,
.
.
Pieicc
AK,
S;ilt7.ni;in
scientific basis
HA. Conterctiee of the
of respiratory therapy.
Rev Rcspir Dis
1
')74;
1
1
(1(6.
Pail
1
):
1
with gray
-1.
piratory therapist,
Respir.atorv
am one of those
my 24 years as a i^es-
Like .Mr .Anderson,
Am
Care
•
in
my hair.
I
In
1
have seen much
February
'96
Vol
41
coi-ne
No
2
:
Letters
and go and
the focus
become more and more
on technology.
Mr Anderson
ticle titles
has listed research and ar-
and seems
to
imply that these
refute the validity of Therapeutic
Part of the
list
cles by Delores Kreiger
Qumn RN
which
In
my
Touch.
includes research and
PhD, and
RN
arti-
PhD. Janet
PhD.
TC Meehan RN
on an
Snyderman MD. The piece concerned Dr
of a health professional's practice.
November
issue,
I
list-
ter at
Columbia Presbyterian Hospital
New York City. Therapeutic Touch
of the program and
The 'bottom
up
then, to
Touch can decrease
lidity
I
also listed
done and colleges and other facilities in
which it is taught. In September 199.'S.
is
learned of another hospital that
porating Therapeutic Touch.
cisco television station
in their
is
line,'
to read,
fomi
and
their
is
that
it
become
is
in-
to ask questions, and,
own
it
fits
opinions as to the va-
into their philosophy of care.
Therapeutic Touch
that costs the patient,
is
not an interaction
and
it
equipment except one's hands.
requires no
1
am
not ad-
I
vocating that Therapeutic Touch be man-
incor-
dated by respiratory care departments as part
The San Fran-
(KPIX) Channel
5,
Eyewitness News, had a segment
of the job
is
as
ever required to learn
tention in the
or, for that matter, that
anything officially to do with
November
is
available for those
it
letter
No
it.
was
one
My
in-
to relay
many hospitals, that
who wish to incor-
as part of their therapeutic inter-
I
welcome Mr Anderson's
letter
of
concern. Differing information and opinions should be available about a subject
so people can be aware and
own
make
their
decisions.
For more information on Therapeutic
Touch
contact:
The Nurse Healers and Pro-
fessional Associates Inc,
lison Park
it at all. It is
is
or use
action with patients.
PA
done
PO Box
444, Al-
15101-0444.
Stephanie Haines
they have
usually not ordered and, generally,
it
information about a holistic intervention,
already being used in
porate
of course,
of Therapeutic Touch, and to decide
whether
celerate the body's
es.
taught to nurses and
is
to individual practitioners to
that support the statements that Therapeutic
own healing processmany hospitals in which it
in
part
is
to the families of patients.
formed,
decrease diastolic blood pressure, and ac-
start-
ed the Cardiac Complementary Care Cen-
ed just six of the clinical research studies
anxiety, decrease pain,
who
Oz, a cardiothoracic surgeon,
actually support Therapeutic Touch.
letter in the
needed basis as part of the scope
about integrative medicine with Dr Nancy
Mad
River
Community
RRT
Hospital
Areata. Califomia
Mark Your Calendars!
Future
November
3-6,
AARC
1996 (Sunday - Wednesday)
San Diego,
December
New
Conventions
California
6-9,
1997
Orleans, Louisiana
November
1998
Atlanta, Georgia
Respiratory Care
•
February
'96 'Vol 41
No
7-10,
143
Notices Df compelilitms. scholarships, fellowships, examination dates, new educational programs, and the like will be
charge. Items for the Notices section must reach the Journal 60 days before the desired
Notices
February
I
for the April issue, etc). Include
Lane. Dallas
TX
75229-459.1.
all
month of publication (January
pertinent information and mail notices to
RFSPIRATORV CARli
I
here free of
listed
lor the
Notices Depl.
March
issue.
KWl
Abies
I
)
1996 Call for Abstracts
Respiratory Care
•
Open Forum
Abstract Format and Typing Instructions
The American Association for Respirator}' Caie and its science journal. RESPIRATORY CARE, invite submission of brief
abstracts related to any aspect of cardit)respiratory care. Tine
be reviewed, and selected authors
abstracts will
\
OPEN FORUM
ited to present posters at the
title in all
AARC
explain content. Follow
title
during the
in
Respiratory Care. Membership
quned for participation.
in the
of
AARC is not
re-
abstract
name. Type or electronically print the abstract \/;/gle spaced in the space provided on the abstract blank. Insert only one letter space between sentences. Text submis-
ill
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re\ iew.
tables are to be attached to the abstract form. Provide all au-
(
1
)
an
ori}»inal study. (2) the eval-
(3) a
ma> ha\ e been
abstract
.
—but
not nation-
meeting and should not have been published previous-
ly in a national journal.
The
abstract will be the only evidence
by which the reviewers can decide whether the author should
be invited to present a poster
the abstract
w
case or case series.
report
nolog} or health-care delivery. The
presented previously at a local or regional
—
encouraged but must he accompanied by
is
a hard copy. Identifiers
habilitation, perinatology/pediatrics, cardiopulmonary tech-
al
authors (in-
aspects of adult acute care, continuing care/re-
ma\
may be
all
one paragraph. Data may be submitted
in table form, (uul simple figures may be included provided
rliev fit within the space allotted. No figures, illustrations, or
uation of a method or device, or
Topics
with names of
presenter" s
Make
An
fust line of
capital letters. Title should
cluding credentials), institution(s). and location. Underiine
sion on diskette
SPECIFICATIONS— READ CAREFULLY!
The
will be photographed.
the abstract should be the
San Diego. California. No\ ember .^-6 1996.
Accepted abstracts will be published in the October 1996 issue
Annual Meeting
Accepted abstracts
will be in-
must provide
at the
all
OPEN FORUM.
Therefore.
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conclusions. Gise specific infomiation.
Do
not write such gen-
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will be discussed."
the abstract
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thor information requested at the bottom of abstract form.
clear photocopy of the abstract
may
abbreviations
A
fonn may be used. Standard
be employed without explanation.
A new
or infrequently used abbreviation should be preceded by the
spelled-out term the first time it is used. Any recurring phrase
or expression
may
the abstract for
(
1
be abbreviated,
)
enors
ures; (2) clarity of language;
specifications.
An
if
and
is first
it
in spelling,
explained.
grammar,
(3)
facts,
conformance
abstract not prepared as requested
Check
and
fig-
to these
may
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Essential Content Elements
Deadline Allowing Revision
Original study. Abstract must include
(
1
)
Background:
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Method: description of research design and conduct in sufficient detail to
pennit judgment of \alidity: (3) Results: state-
ment of research findings with quantitative data and statistical analysis: (4) Conclusions: inteipretation of the meaning
Authors may choose to submit abstracts early. Abstracts
postmarked b\ February 11. 1996 will be re\iewed and the
authors notified by letter only to be mailed by March 22,
1996. Rejected abstracts will be accompanied by a written
critique that should, in
of the results.
Method/device evaluation. Abstract must include
ground: identification of the method or de\ ice and
( 1 )
its
ity; (3)
Back-
judgment of
its
28, 1996).
Final Deadline
objectivity and valid-
Results: findings of the evaluation; (4) Experience:
of the author" s practical experience or a lack of ex-
summary
cases, enable authors to revise
intended
function; (2) Methitd: description of the evaluation in sufficient detail to permit
many
their abstracts and resubmit them by the final deadline (April
perience; (5) Conclusions: inteipretation of the e\aluation and
The mandatoi7
Final Deadline
is
April 28 (postmark).
Au-
thors will be notified of acceptance or rejection by letter only.
These
letters will
be mailed bv July
15. 1996.
experience. Cost comparisons should be included where possible
Mailing Instructions
and appropriate.
Case
report. Abstract must report a case that
mon or of exceptional
is
uncom-
educational value and must include
( I
Introduction: Relevant basic information important to understanding the case. (2) Case
Summary:
Patient data
details of interventions. (3) Discussion:
flect results
and response,
Content should
in
the case and a case-managing physi-
cian must be a co-author or must approve the report.
Respiratory Care
•
February
"96
Vol 41 No
2
(
Do
not fax
(if
!
2 clear copies of the completed abstract
)
possible),
and a stamped, self-addressed post-
card (for notice of receipt)
to:
re-
of literature review. The author(s) should have
been actixely involved
Mail
form, diskette
Respiratory Care Open Forum
1
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.
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Abstract
Form
Title
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must be
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in all
(capital)
authors' full
names and
text in
upper and lower case.
2.
Follow
title
with
all
names
authors"
including credentials
(underline presenter's
name
I.
and
institution,
kxration.
.\
Do
not justify
(ie.
leave a "ragged" right
margin).
Do
4
not
u.se type size
than 10 points.
le.ss
5.
All
tc.\t.
tlgiires
tables,
must
the rectangle
6.
into
shown.
Submit 2 clean copies.
This fonn may be
photocopied
o
and
tit
if
multiple abstracts
E
;ire
to be submitted.
Mail original &
photocopy
1
(along with postagepaid postcard) to
Respiratory Care
Open Forum
11030 Abies Lane
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TX 75229-4593
Early deadline
Febnuuy
11.
is
1996
(postmark)
Final (leadline
is
April 28. 1996
{postmark)
13.9
Name &
Credentials
Mailing Address
Voice Phone
Name &
& Fax
Credentials
Mailing Address
Voice Phone & Fax
cm
or 5 5"
RE/PIRATORy QVRE
Manuscript Preparation Guide
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Update:
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A report of subsequent developments
critically
reviewed
in a topic that
has
Journal or elsew here.
in this
original manuscripts related to
respiratory care and prepared according to these Instructions.
who
Manuscripts are blinded and reviewed by professionals
experts in their fields. .Authors are responsible for
all
are
aspects of
A
Point-of-View Paper:
tiated opinions
paper expressing personal but substan-
on a pertinent
topic. Title Page. Text. References,
may be
Tables, and Illustrations
included.
the manuscript and receive galleys to proofread before publication.
is
Each accepted manuscript
clear and
it
conforms
is
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may
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ing categories
pertinent paper not fitting one of the forego-
may be
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with the Editor before writing or submitting such a paper.
where without permission.
A paper drawing attention to a pertinent concern:
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Editorial:
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&
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blood-gas values
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ification.
tion
of
It
A
mod-
has a Title Page. Abstract. Introduction. Descrip-
Evaluation
Methods.
Evaluation Results. Discussion. Conclusions, Product Sources,
Acknowledgments. References. Tables. Appendices. Figures,
report of a clinical case that
a
new way.
or
is
is
A
physician must either be an author or furnish a
duction.
Case
Its
components
uncommon,
or
exceptionally instructive. All
authors must be associated with the case.
the manuscript.
case-managing
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and
Article:
letter
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A
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been the subject of
case report involving
Drug Capsule: A mini-review paper about
a drug or class of
and pharmacotherapy.
Kittredge's Corner:
and
editorial
PFT
A
equipment
piratory care
brief description of the operation of res-
— with information
comments and
from manufacturers
suggestions.
Corner: Like Blood Gas Corner, but involving pulmonary
Test
ing
Your Radiologic
Like Blood Cjas Corner, but involv-
radiographs,
may
involve imaging techniques other than conven-
tional chest radiograph).
Review of Book, Film, Tape, or Software:
A
balanced, critical
review of a recent release.
critical
summary of
review of the
Preparing the Manuscript
litera-
a pertinent topic that has
40 published research
articles. Title
Print
on one
Page. Outline. Introduction. Review of the Literature. Summary.
mm)
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at least
Skill:
pulmonary medicine radiography and including one or more
are Title Page. Abstract. Intro-
Figures, and Figure Captions.
ture
brief, instructive
function tests.
and Figure Captions.
Case Report: A
was managed in
A
— with Questions. .Answers, and Discussion.
description and
device, method, technique, or
Device/Method/Technique.
publication."
drugs that includes discussions of pharmacology, pharmacokinetics,
new
Mark "For
included.
Blood Gas Corner:
report of an original investigation (a study).
an old or
in this
Structure
includes a Title Page. Abstract, Introduction. Methods. Results.
i)f
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Journal or about other pertinent topics. Tables and illustrations
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page. LIse douhle-spacing throughout the entire manuscript. Use
and Captions may be included.
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Manuscript preparation Guide
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page. Repeat
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title
Letter in journal:
only (no
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new
Page. Abstract. Text. Product-Sources
page; Title
Aelony Y. Ethnic norms
8.
List.
pulmonary function
for
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Chest I991:99(4);I05I.
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Use standard English
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Paper accepted but not yet published;
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and small
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whenever
works
published
only
Cite
Manuscripts accepted but not yet published
therapies for asthma. Respir Care (year, in press).
possible.)
DeRemee RA.
10.
disease.
References.
New
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cited
Equipment,
Patients.
Hess D.
9.
Center main section headings on the page and type them in capital
and small letters (eg. Introduction. Methods. Results.
New
pulmonary
Clinical profiles of diffuse interstitial
York: Futura. 1990:76-S.S.
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as
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Corporate author book:
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Department of Drugs.
CO;
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AMA
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in
On
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the
Chapter
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1
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2.
in
in
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Pierce
editor(s):
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AK. Acute
editors.
CA. Welch MH.
Pulmonary medicine. Philadelphia: JB Lippincott. 1977.
authors.
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Rau
JL.
Harwood
RJ.
Comparison of nebuli/er delivery methods
through a neonatal endotracheal lube; a bench study. Respir Care
I992;37(II);I23.1-I240.
m
Article
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Idiopathic interstitial
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tion. Start
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A
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1986:89(3. Suppll;l39S-l43S.
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Can we
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D
Rephnts:
Yes
No
;
approve its
"We, the undersigned, have all participated in the work reported, proofread the accompanying manuscript, and
and
state. If
city
appointments,
academic
institution,
title,
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include
print
and
submission for publication." (Please
form.)
of
this
another
copy
use
please
authors,
that
4
more
Author Name:
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Has
If
yes, where,
Has
If
research been presented
this
this
in
a public forum?
'^,
Yes
U
No
when and by whom?
research received awards?
D
Yes
D
No
yes, please describe,
Do any
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of the authors
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No
If
have a
financial interest in the products
mentioned
in this
paper or competing products?
yes, please disclose:
Checklist:
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C
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n
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C
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n
n
D
Is
double-spacing used throughout entire manuscript?
all pages numbered in upper-right corners?
Are
all references, figures, and tables cited in the text?
Has the accuracy of the references been checked, and are they
Have SI values been provided?
Has all arithmetic been checked?
Have generic names of drugs been provided?
Have necessary written permissions been provided?
Have authors' names been omitted from text and figure labels?
Have copies of 'in press' references been provided?
Has the manuscript been proofread by all the authors?
Are
correctly formatted?
Respiratory Care
—
New
Products
News
& Services
releases about
these listings.
new
produels and services will be considered for pubiication
Send descriptive
Products and Services Dept.
sor has a
1
1
in this section.
There
is
no charge
release and glossy black and white photographs to Ri^.spir.xtory Cari^ Journal,
1()3U
Abies Lane. Dallas
TX
75229-459.1.
-year wairanty. For a complete
cross-reference listing, call
VTI
for
New
at (8(X))
cure'", a
new
holder for nasogastric tubes,
nasal feeding tubes, and
According
oxygen can-
company,
550-0856. please mention RH.SPIR.AI()RY
nulas.
CarE; or write to Vascular Technolo-
holder feauires a moisture-resistant foam
Ave,
cushion to reduce pressure to the patient's
gy
Inc.
Dept RC. 25
Chelmsford
MA
Industrial
01824. (508) 250-0856.
nostnls and up|X'r
to the
the
The hvpoalleigenic
lip.
holder attaches to the dry area of a patient's
cheeks and helps eliminate the
need for constant retaping by securely
holding the tube with a resealable
For details, contact
at
2037
J
&C
tlap.
M C Johnson Co Inc
Blvd. Naples
FL 33942Remem-
Nebilizer Compressor System.
6213. or
Medical Industries .America Inc
intro-
ber to mention Re.SPIRATORY Cari-
duces the AertiMax Nebulizer
Com-
when you
The AeroMax
akiminum compressor
pressor System.
a die-cast
sembly and
a 3-prong
call
(800) 553-8483.
call.
features
a strong
grounded
ABS
as-
plastic case,
electrical cord,
and
removable nebuli/cr tubing. According
to the manufacturer, the
AeroMax
also
features a unique benefit for children
the
Max
Pax.
The Max Pax contains
stickers for the
and
AeroMax compressor
an activity/instruction booklet de-
Generic Inhalation Aerosol.
signed to familiarize children with the
DEY
use ol the nebulizer compiesse)r. For
Inhalation Aerosol metered-dose inhaler,
in-
formation call (800) 759-3038. Don^t
forsiet to
mention Rr.Sl'lR.ATORY CARE.
Laboratories
now
offers Albuterol
a generic alternative to Proventil
"
and
Ventolin". According to the company,
albuterol
and
is
relief
indicated for the prevention
of bronchospasm
in patients
with reversible obstructive airway disease and acute attacks ot bronchospasm.
For infomiation about indications, contraindications,
Laboratories
and side
at
effects, call
DEY
(800) 755-5560. Don't
foraet to mention Ri:sPlR,\T()RV CARli.
MEI ABOLIC MEASI REMENT SYSTEM. Par\iiMedics introduces MMS2400 Metabolic Measurement System,
a compact integrated system for maximal
Oi consumption
sures Vo,, Vc()..
Oxy(;en Sensor. Vascular Technology
Inc
vanic
(
VTI
1
Oxygen
the sensor
is
variables.
the
releases the VTI-.58() Gal-
Sensor.
VTI
suggests that
designed as a direct
ic
and
placement for the oxygen sensors used
MiniOx
tion, the
oxygen sensor can be used
I. II,
a replacement for
factured
15:
and
III.
by several companies.
F.acii
call
as
sen-
to
ParvoMedics,
includes paramagnet-
CO:
g''^
analyzers, mix-
printer.
Bike ergometer and tread-
mill options are available.
In addi-
equipment manu-
indi-
ing-chamber, pneumotach, computer,
re-
with the
O:. infrared
and
RQ. REE. and other
According
MMS-240()
testing
assessment that mea-
rect calorinietry
Na.sogastric Tube Holder.
.lohnson C(>mpanv Inc offers
NG
For
Consentius Technologies
details,
at
(800)
MC
942-7255. Please mention Re.SPIR.'XTORY
Se-
Care when vou
Respiratory Care
•
call.
February
"96
Vol
41
No
2
.
New Products &
Services
mising performance. In addition, the
monitor displays on-line help on a high
visibility screen.
The SC-210 may be
used for intubated and noninmbated patients.
For infonnation contact the com-
pany at N93 W 14575 Whittaker Way,
Menomonee Falls WI 53051. Please
mention Respir.ATORY Care when
voucall(8()0)PRYONCO.
analysis and trending, and b\ improving the accuracy of billing information,
reports,
and
logs.
LabManager
dows-based application
Microsoft's
that
is
Win-
a
works with
Windows', Windows 95®,
NT*
and Windows
The program can
operating systems.
retrieve data
from up
4 different brands of analyzers simultaneously and can exchange data
to
w ith hospital mainframe and other comHIS
puter systems via a real-time
terface.
For
details, write to
LM
in-
Soft-
ware. Dept RC. 4140 Oceanside Blvd
#159-410, Oceanside
forget to mention
when you
Cost-Rediction
Medical-Gas
call
CA 92056.
Don't
RESPIRATORY CARE
(619) 631-1343.
Nellcor Puritan Bennett releas-
Plan.
es a program designed
to help health-
care institutions control the costs, in\
entor\ maintenance, and uses of
ical
gases. According
med-
company,
to the
the brochure, "Providing Services Tai-
lored to Address
Needs,"
will help
Your Gas Product
reduce the
total cost
Infant \L\NNEQIIIN.
Laerdal Medical
of buying and using medical gases. For
Coiporation announces the
a copy of the brtichure. contact Nellcor
Anne'
Puiitan Bennett
Gas
Products. Dept
9101 Bond. Overland Park
KS
66214.
or phone (913) 49.^-3610. Please
tion
RC.
men-
Respiratory Care when \ou
call.
ing
'.
mannequin with
conect head
rise
new Baby
an infantlike, low-cost
tilt
luid
a
CPR train-
mo\able jaw
chin
lift,
for
natural chest
during ventilation, and a realistic
mouth and
nose. Tl:e
mannequin
also in-
cludes a removable face that can be
in-
HOLTER Recorder.
new
Del Miu A\
ics releases
and a disposable airway for easy clean-
recorder that accurately captures
ing.
is
According
a\ ailable for
as quadruplets
to Laerdal,
Baby Anne
classroom or group use
— four mannequins
in a
a
recordings. According to the
facturer, the
it>n-
digital Holler patient
terchimged with Laerdal's Resusci' Baby
ECG
manu-
Model 483 DigiCorderT"^
incorporates a unique digital
memory
con\ enient cany ing bag with a separate
and advanced electronics that eliminate
storage compartment for faces, con-
data compression, which
nectors, jaws
details, call
imd disposable
Laerdal
Please mention
at
aiivsa\
s.
For
(800) 649-185
1
RESPIRATORY Care.
may
intiodtice
en'or into arrhythmia and ST-segment
analysis. In addition, the
be used with other Del
and
DigiCorder can
Mar
scanners
features set-up instaictions in 5 lan-
guages, a cairying pouch, an event but-
SiDESTREAM CO2 MONITOR. Pryon
Laboratory Management Soft-
Corporation introduces the SC-21()
\\
sidestream
CO2
the monitor
tle.xible.
is
monitor. Pryon claims
easy to use, portable and
and reaches
full
specifications in seconds.
laboratory
management software, LabABG for Windows. The
Manager^"^
company claims
the software
The moni-
signed to improve
quality control in the
and withstands excessive patient secretions or moisture w ithout compro-
•
LM Software announces a new
operating
tor features continuous self-calibration
RESPIRATORY Care
ARE.
February
"96
is
de-
ton to identify specific medical episodes,
and an aku-m
are included. For details, write to Del
Mar
Avionics. Dept RC. 1621 Alton
Ave. Irvine
storage of historical calibration data for
TORY Care.
41
No
2
of a low
trode extension cables and electrodes
blood gas lab by providing comprehensive data management, retrieval, and
Vol
to alert the patient
battery or a ct>mponent failure. Elec-
CA
92714. or
call
(714)
250-3200. Please mention RESPIRA-
153
omm
Now.
Introducing
a
new high-tech benefit
AARC mem-
for
It's
Easy To Get Onto
bers that allows you to share information with your
AARC Online:
e-mail,
Member Benefit.
tion about particular timely topics,
ing
download documents and search
and managed
care.
You can
concerns on onhne message boards and
conferences.
Members And
Professional
AARC
Get Immediate Access To
Infomiation like Hie
find
them
out. or
AARC Clinical
Practice
When You
more
YES! Send my
1
currentK ha\e a
S9.
95
modem: Yes
-
dow nload them
24 hours
available.
to
_\
them
l
No:
VISA
pay
choose a month!} charge of Si 4. ^).\ which includes 3
at
$9.95 per hour.)*
It!
you need,
online, print
them
documents and
ow)
no monthly minimum
S9.95 per hour,
Fax or mail the reply form
$14.95 per month (includes 3 hours)
S P
EXP
^£ W .5
MC
U
AMEX
D
Spaci:Works. Inc.
Fax: 301-738-9284
DISCOVER
51
Monroe
1995 Sp,\ci Works.
Inc.
ille.
Or
SKtNATLRE:
f
Street. Plaza
D.^TE:
Rock\
arc billed at a hieher rale,
s
»: ._
L
.
FAX:
k
to:
=
NAME ON CARD:
_
IS.
to
a dav. seven davs a week!
CREDIT CARD
oiiisijo ihe continental
You can choose
hour with no monthly minimum, or you can
Preferred [filling Method: (select
COMPANY:
.
the
economi-
our ow n computer. Miu also
AARC MEMBER
TEL:
are two
SpkeU ORhS Sofhvare Kit For AARC Online!
TITLE:
CITY STATi: ZIP
payment plans
SQ.Q.^ per
in "'real-time"
for the guidelines
yourself, then read
u
D
ADDRESS:
modem, and
AARC Clinical Pnuiice
You can search
NA.MI;:
•Areas
JSeed
iia\e access to newsletters, articles,
Guidelines.
3.1. a
SpaceWorks software. There
pro\ ides 24-hour access to important
information, like the
Guidelines.
cal
AARC Online is a PC
hours of connect time, (Additional hours are billed
Information
Colleagues.
$9.4.^
such as restructur-
AARC
Heodquorlers,
for informa-
also share ideas and
Communicate Online With
you need
running Microsoft Windows
respiratory care colleagues, send and receixe Internet
AARC's Newest
Critical
All
AARC Online.
to access
Spacf.Works
i.s
a
sen ice
inark of Sp.ace Works. In
One
MD ZOS.'^O
call:
I-800-5-SP.4CE-5, Ext. 2170
.
.
.
American Association
for
Please read the eligibility requirements for each of the classifiin the nght-hand column, then complete the applicable
section. All information requested below must be provided,
except where indicated as optional. See other side for more
information and fee schedule. Please sign and date application on reverse side and type or pnnt clearly. Processing of
application takes approximately 15 days.
cations
D
Respiratory Care Membership Application
FOR ACTIVE MEMBER
An
individual
pnor
to
eligible
is
moving outside
mandates such.
care.
OR
Member
he/she
its
lives in the
US,
or
its
terntories or vi/as
borders or territones, and meets
OR
(2) is
ONE of
good standing on December
membership remains
in
if
an Active Member
the following critena:
employed
in
a graduate of an accredited educational program
holds a credential issued by the
(3)
in
if
credentialed as a respiratory care professional
(1) IS legally
Place
Active
.
,
good
NBRC, An
1994
8,
will
who
individual
is
an
a slate
in
that
respiratory
AARC
Active
continue as such provided hislier
standing.
Employment
of
Associate
^
Foreign
Address
D
Physician
City
"
D
D
Last
Name
First
Name
Industrial
Zip.
State
Special
Phone No.
Student
J
(
Medical Director/Medical Sponsor
FOR ASSOCIATE OR SPECIAL MEMBER
Middle
_
hold a position related to respiratory care but do not meet the
who
Individuals
Social Security No.
quirements
of Active
Member
shall
be Associate Members They have
all
of the rights
re-
and
benefits of the Association except to hold office, vote, or serve as chair of a standing
Home Address
committee. The following subclasses of Associate Membership are available: Foreign,
Physician,
City
devoted
Special
-Zip.
State
Phone No.
and
to the
Industrial (individuals
whose primary occupation
is
directly or indirectly
manufacture, sale, or distnbution of respiratory care equipment or supplies)
Members
are those not working
a respiratory care-related
in
field.
PLEASE USE THE ADDRESS OF THE LOCATION WHERE YOU PERFORM YOUR JOB.
NOT THE CORPORATE HEADQUARTERS IF IT IS LOCATED ELSEWHERE
(.
Place
Employment
of
Primary Job Responsibility (check one only)
Technical Director
D Assistant Technical Director
D Pulmonary Function Specialist
D Instructor/Educator
D Supervisor
n Staff Therapist
Address
n staff Technician
D Rehabilitation/Home
FOR STUDENT MEMBER
City
Phone No.
Care
Individuals
n Medical Director
n Sales
n Student
D Other, specify
be classified as Student Members
accredited by, or
in
all
the requirements for
in
respiratory care
AARC-recognized
not receive Continuing Respiratory
Upon completion of your
may be pursued upon your
transcnpts.
continuing education credits
Care
respiratory care education,
reclassification to Active or
Associate Member.
Skilled Nursing Facility
School/RC Program
Educational Institution
Address
Manufacturer or supplier
City _
specify
Sex
of Birth (optional)
U.S. Citizen?
Yes
(optional)
Zip.
Phone No.
Lj
when? From
Preferred mailing address:
American Association
.)
(_
Length of Program
No
Have you ever been a member
so,
they meet
the process of seeking accreditation from, an
State
If
if
an educational program
— Student Members do
SPECIAL I^OTICE
Education (CRCE)
Hospital
n Other,
Date
in
agency.
n DME/HME
D Home Health Agency
D
D
will
(_
Associate Membership and are enrolled
Type of Business
„
D
-Zip.
State
of the
AARC?
for Respiratory
year
i;
4 years
Z Other, specify.
Expected Date of Graduation (required information)
to
Home
1
n 2 years
Care '11030 Abies Lane
Year
Month
Business
•
Dallas,
TX 75229-4593
•
(214) 243-2272
•
FAX
W^^"
'
American Association
for
Membership Fees
Demographic Questions
Payment must accompany your
We
request that you answer these questions
us design services and programs
to
in
order to help
meet your needs.
Fees are
High School
Associate Degree
n
D
Master's Degree
Number
S80.00
D
D
D
D
n
Graduate Technician
Bachelor's Degree
for
Active
S77.50
Associate (Industrial or Physician)
$77.50
Associate (Foreign)
$92.50
Special
$77.50
Student
$35.00
D
n
0-2 years
3-5 years
1 1 - 1
5 years
Established to recognize the specialty areas of respiratory
6-10 years
care.
Job Status
Full
The sections
Time
Part
national
n RRT
D LVN/LPN
D CPFT
D RPFT
D Perinatal/Pediatric
CRTT
Physician
D CRNA
D RN
Salary
Less than $10,000
$10,001-820,000
$20,001-330.000
$30,001 -$40,000
$40,001 or more
PLEASE SIGN
hereby apply for membership in the American Association for Respiratory Care
and have enclosed my dues,
approved for membership in the AARC, will
abide by its bylaws and professional code of ethics
authonze investigation of
all statements contained herein and understand that misrepresentations or
omissions of facts called for is cause for rejection or expulsion
I
if
I
I
yearly subscription to Respiratory
includes an allocation of $6.50 from
Contributions or
gilts to
Care
AARC
the
and AARC Times magazine
each of these publications.
journal
my dues
for
are not tax deductible as charitable
income tax purposes. However, they may be lax deductible as
ordinary and necessary business expenses subject to restrictions imposed as a
result of association lobbying activities. The AARC estimates that the
nondeductible portion of your dues the portion which is allocable to lobbying
contributions for
-
is
26'.'
Signature
Date
of specific
concern
AARC
meetings.
Time
^1
D
D
D
D
D
publish a newsletter four times a year that
to that specialty.
The
sections also design the specialty programming at the
Credentials
NOTE:
$
Specialty Sections
16 years or more
focuses on issues
^
for
Doctorate Degree
TOTAL
D
AARC.
Associate-Foreign status: and $35.00
of Years in Respiratory Care
D
n
n
A
application to the
12 months. (NOTE: Renewal fees are $65.00
Student status.)
Check the Highest Degree Earned
„
for
Active, Associate-Industrial or Associate-Physician, or Special
status;
RC
I
Respiratory Care Membership Application
-
Adult Acute Care Section
MECJ^TCH
m
IHh
\
M
KUIHK
MUl
IS
Kt I'llK
I
I
PKdl.K
^t.
V
M
Patient identifier
'
Age
at
Sex
3
or
I
I
I
I
Date
4
Weight
Name
1
Triage unit
sequence #
igive labeled strength
& mfr
labeler,
kgs
3
Dose, frequency & route used
2
B. Adverse event or product problem
Outcomes
2
(check
Q
all
and
or
Product problem
I
I
I
I
#1
permanent impairment/damage
hospitalization -
°^^^'
LD
or prolonged
Lot #
Date of
Dgggfy"'
known)
7
Exp. date
known)
(if
#1
«2nyesn"o
Dgg^Py"''
Event reappeared after
8
reinlroduction
1*2
Describe event or problem
5
(if
#1
this report
event
Dyes Dho
#1
6
4
3 Date of
Event abated after use
stopped or dose reduced
5
(indication)
#1
required intervention lo prevent
life-lhrealening
initial
Diagnosis for use
4
congenital anomaly
death
I
unknown, give duration)
(if
best eslimale)
tt2
disability
I
{ot
defects/malfunctions)
attributed to adverse event
thai apply)
I
[
le g
Therapy dates
trom 10
#1
Ad-Iverse event
known)
it
#1
female
male
of birth:
confidence
0910-0291 Expires: 1/3V96
0MB statement on reverse
C. Suspect medication(s)
time
of event:
In
See
FDA Use Only (RESP CARE)
Page
A. Patient information
1
0MB No
Form Approved
VOLUNTARY
reporting
For
bv health professionals of adverse
events and product problems
Dyes Dno
Dt°pf,ff
ssDyesDno
Dggfy"''
#1
NDC
9
# (for product problems onlyi
Concomitant medical products and Iheiapy dates (exclude treatment
10
of event)
Suspect medical device
D.
Brand name
2
Type
3
lUlanufacturer
of device
name & address
Operator of device
4
I
I
I
I
I
I
health professional
lay user/patient
other
5
Expiration date
7
If
6
model # _
6
Relevant tests/laboratory data, including dates
catalog #
implanted, give date
Imo dav
v
serial #
If
lot#
explanted. give date
jmo.day.'yr)
other #
9
(Do not send
Device available for evaluation?
I
n
yes
I
Q
no
FDA)
to
relurned to manufacturer on
Concomitant medical products and therapy dales (exclude treatment
7
of event)
Other relevant history, including preexisting medical conditions (eg, allergies,
race, pregnancy, smoking and alcohol use, hepaticrenal dysfunction, etc)
Reporter
E.
)
2
Mail to:
MIhWaKH
or
5600 Fishers Lane
Rockville, MD 20852-9787
FDA Form 3500
(6/93)
FAX
1
5
8.
(see confidentiality section on back)
phone
address
Health professional?
D
to:
-800-FDA-01 78
Name
yes
D
3
#
Occupation
manufacturer
you do
I
I
I
I
no
user
facility
NOT want
your identity disclosed to
X in this box.
the manufacturer, place an
If
Also reported to
4
"
distributor
'
I
j
[
|
Submission of 3 report does not constitute an admission that medical personnel or the product caused or contrit-uted to the event.
ADVICE ABOUT VOLUNTARY REPORTING
How to
Report experiences with:
•
medications (drugs or biologies)
•
medical devices (including
•
special nutritional products (dietary
supplements, medical foods, infant formulas)
•
other products regulated by
Report
is
SERIOUS adverse
in-vitro
diagnostics)
FDA
death
•
life-threatening (real risk of dying)
•
hospitalization
•
disability (significant, persistent or
(initial
or prolonged)
permanent)
•
attach additional blank
•
use a separate form
•
report either to
in
fill
all
FDA
products except
pages needed
each patient
if
for
or the manufacturer
(or both)
to
FAX
report
modem
•
1-800-FDA-7737
to report
by
•
1-800-FDA-1088
to report
by phone or
for
more information
congenital anomaly
•
required intervention to prevent permanent
Report even
use section C for
medical devices
Important numbers:
• 1-800-FDA-0178
•
impairment or
•
An event
outcome is:
•
the sections that apply to your report
just
events.
serious wlien the patient
report:
•
•
fora VAERSform
for vaccines
1-800-822-7967
damage
If your report involves a serious adverse
event with a device and occurred m a facility outside a doctor's office, that facility may be legally required
if:
it
•
you're not certain the product
caused the
event
•
to report to
you don't have
all
the person
the details
Report product problems -
quality,
performance
or safety concerns such as:
FDA
Confidentiality: The patient's
confidence by FDA and protected
•
suspected contamination
the law.
•
questionable
self-reporter,
•
defective components
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Health
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Training Institute (MTl) Independent Study Program
February 20-23 in Reno, Nevada. The NSRC and the American
Lung Association of Nevada
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ALA
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Baltimore, Maryland. The Johns Hopkins
Southshore Lake Tahoe, California. Chapter 9 of the CSRC presents the KSlh Annual Tahoe Conference. "Setting the Sails into the Winds of Change," at the Em-
March 13-14 in
bassy Suites. CRCE credit has been requested. Call
Johns Hopkins University School of Medicine's Turner Auditorium. Topics include sleep-disordered breathing, pulmonary
March LV-15
lego. (510)
in
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Adult and Pediatric Respiratory Care,"
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April 18-19 in
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California. Chapter 2 of the
Horizons
in
Respiratory Care."
Hyatt Regency Suites. Presentations include
at the
New Modes of
injury, nitric oxide. Joint
at
Com-
mission preparation, and liquid ventilation. The seminar
approved for
at
1
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is
Brown
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Mechanical Ventilation, Invasive Pulmonology. and Clinical Application of
Metabolic Monitoring.
been requested. Contact
CRCE credit
has
Tom Taylor at the following phone/fax
number: (909) 777-3214.
March
tact the
May
24
New
Hampshire Society
in
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for Respiratory
Vermont-
Care presents
its
.
Mount Washington.
tact Bill
Hay
at
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MT 59601,
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"CE
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CRCE credit has been requested. Con-
(603) 267-7406.
April 9-15, 1996 in Miami, Florida. The Ventilation Assisted Children's Center (VACC) of Miami Children's Hospital
Division of Pulmonology announces
its
free
camp
for
ventilation-assisted children and their families. Activities
conjunction with the University of Texas Health Science
swimming, games, arts, and crafts. The
application deadline for overnight campers was January 5,
San Antonio, and Wilford Hall Medical Center, an-
1996. Contact Director Moises Simpser or Coordinator Cathy
May 24 in San Antonio, Texas. The TSRC (Alamo District),
in
Center
at
nounce the
at the
1st
Annual Riverwalk Respiratory Symposium
Marriott Riverwalk. Topics include the future of res-
piratoi7 care, the impact of
managed
protocols, and sleep studies.
ed.
care,
implementing
RC
include field
Klein,
trips,
VACC,
Hospital.
Division of Pulmonology,
3200
SW
60th Ct, Suite 203.
Miami Children's
Miami FL 33155-
4076, (305) 662- VACC, fax (305) 663-8417.
CRCE credit has been request-
Contact the University of Texas Health Science Center
San Antonio. Department of Respiratory Care, 7703 Floyd
Cud Dr., San Antonio TX 78284-7784, (210) 567-3706.
at
May
10-15 in
New Orleans, Louisiana. The American Lung
Association/American Thoracic Society hosts
ternational Conference.
The
its
annual In-
conference features informa-
on the prevention, control, and management of lung disease. For more information, write to the 1996 Internationtion
May
1-June 30
— Management Training
deadline to enroll
in
Module
Managerial Accounting Part
Respiratory Care
•
2
1
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(Communication Skills and
and Module 6 (Business and
February
'96
Vol
41
No
2
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Anderson,
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A
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Comroe
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H
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