Evolución de la VM con presión positiva Historia, principios físicos

Transcription

Evolución de la VM con presión positiva Historia, principios físicos
Evolución de la VM con
presión positiva
Guillermo Bugedo
Departamento de Medicina Intensiva
Pontificia Universidad Católica de Chile
[email protected]
Sunday, April 25, 2010
evolución de la VM con presión positiva
•
•
•
•
•
historia
principios físicos básicos
SDRA y fisiopatología
daño inducido por la VM y ventilación protectora
generaciones de ventiladores
Sunday, April 25, 2010
“…you must attempt an opening in the trunk of the trachea and
pass into it a tube…, …and you must blow into this so that the
lung may expand…, …and the heart take strength afresh and
exhibit a great variety of motions”.
From “De humani coporis fabrica”, by Andreas Vesalius (1543).
Sunday, April 25, 2010
Robert Hooke
(1635-1703)
Sunday, April 25, 2010
1667: Keeping a dog alive by blowing through its lungs with bellows
Sunday, April 25, 2010
1667: Keeping a dog alive by blowing through its lungs with bellows
Hooke's law: the stress imposed on a solid is directly
proportional to the strain produced, within the elastic limit
Sunday, April 25, 2010
Sunday, April 25, 2010
(+)
Sunday, April 25, 2010
(+)
(-)
Sunday, April 25, 2010
(-)
“Spirophore”
Eugéne Woillez, 1876
Sunday, April 25, 2010
the “iron lung”
Sunday, April 25, 2010
1952: la epidemia de poliomielitis y los
ventiladores de presión positiva
Sunday, April 25, 2010
epidemic of poliomyelitis in Copenhagen
• “It is doubtful indeed if any city of the size of
Copenhagen has ever experienced an outbreak of
similar magnitude ... for many weeks we received
thirty to fifty patients daily, of whom six to twelve were
desperately ill ... drowning in their own secretions.
• As we felt that the application of modern principles of
anaesthesia to the problem of obstructed airways and
respiratory insufficiency in poliomyelitis might
improve our results anaesthetists were invited to join
our staff, the first being Dr. Bjørn Ibsen.”
Lassen HCA (1954) The Epidemic of Poliomyelitis in
Copenhagen, 1952. Proc Roy. Soc. Med 47:67
Sunday, April 25, 2010
epidemic of poliomyelitis in Copenhagen
Sunday, April 25, 2010
epidemic of poliomyelitis in Copenhagen
•
Dr Bjørn Ibsen was called
into consultation on August
25th.
•
In the preceding three weeks
there had been 31 patients
with life threatening
poliomyelitis; 28 of these had
died.
Bjørn Ibsen
Lassen HCA (1954) The Epidemic of Poliomyelitis in
Copenhagen, 1952. Proc Roy. Soc. Med 47:67
Sunday, April 25, 2010
epidemic of poliomyelitis in Copenhagen
•
On August 27th the first
patient was treated with the
method that was to become
the treatment of choice:
– tracheotomy just below the
larynx
– inflatable rubber cuff tube in
trachea
– frequent suction
– repeated bronchoscopy
– postural drainage
– manual positive pressure
ventilation using oxygen
and nitrogen.
Lassen HCA (1954) The Epidemic of Poliomyelitis in
Copenhagen, 1952. Proc Roy. Soc. Med 47:67
Sunday, April 25, 2010
manual positive pressure ventilation
Sunday, April 25, 2010
epidemic of poliomyelitis in Copenhagen
• At times there were as many as 70 patients requiring
artificial respiration.
• Students from the University provided the manpower
(handpower!). Overall 1400 students were involved
during the course of the epidemic. None of them
contracted the disease.
• By the end of the year the mortality in these severe
cases had fallen from 87% to 26%.
Lassen HC. A preliminary report on the 1952 epidemic of poliomyelitis
in Copenhagen with special reference to the treatment of acute
respiratory insufficiency. Lancet. 1953 Jan 3;1(6749):37-41.
Sunday, April 25, 2010
los ventiladores de presión
Sunday, April 25, 2010
first use of the Clevedon ventilator
Macrae et al, September 1953
Sunday, April 25, 2010
P límite
P
t
V
t
gentileza Dr J. Urzúa
Sunday, April 25, 2010
P límite
P
t
V
t
gentileza Dr J. Urzúa
Sunday, April 25, 2010
ventilador de presión
IN: t
LIM: P
Presión
(cmH2O)
Flujo
(lpm)
ventilador de
presión
Sunday, April 25, 2010
CIC: P
ventilador de presión
IN: t
LIM: P
Presión
(cmH2O)
Flujo
(lpm)
ventilador de
presión
Sunday, April 25, 2010
CIC: P
ventilador de presión
IN: t
LIM: P
Presión
(cmH2O)
Flujo
(lpm)
ventilador de
presión
Sunday, April 25, 2010
CIC: P
ventilador de presión
riesgo de hipoventilación
IN: t
LIM: P
Presión
(cmH2O)
Flujo
(lpm)
ventilador de
presión
Sunday, April 25, 2010
CIC: P
-pat restrictiva
-pat obstructiva
-tos
-desadaptación
Bird Mark 7
circa 1955
Sunday, April 25, 2010
Puritan-Bennett PR-2
circa 1963
Sunday, April 25, 2010
la medicina intensiva había nacido…
Sunday, April 25, 2010
Ashbaugh DG, Bigelow DB, Petty TL, Levine BE
Acute respiratory distress in adults
Lancet, 1967 Aug 12
Sunday, April 25, 2010
• The article outlined clinical, radiological, biochemical
and pathological features of a pattern of acute
respiratory distress in 12 patients:
• “The clinical pattern... includes severe dyspnoea,
tachypnoea, cyanosis that is refractory to oxygen
therapy, loss of lung compliance, and a diffuse
alveolar infiltrate seen on chest X-ray”.
• It was noted that none of the patients had chronic
lung disease and the precipitant of the disorder was
varied with severe trauma preceding onset in seven
patients, viral infection in four patients and
pancreatitis in one patient.
Ashbaugh DG, Bigelow DB, Petty TL, Levine BE
Acute respiratory distress in adults
Lancet, 1967 Aug 12
Sunday, April 25, 2010
• Chest X-ray appearances consisted of “patchy,
bilateral alveolar infiltrates”, the severity of which
paralleled the clinical condition.
• “At necropsy in seven patients, gross inspection
showed heavy and deep reddish-purple lungs... the
appearance resembled liver tissue”.
• Microscopic appearances were consistent with
current descriptions, including the hyaline
membrane which prompted comparison with
neonatal respiratory distress syndrome.
Ashbaugh DG, Bigelow DB, Petty TL, Levine BE
Acute respiratory distress in adults
Lancet, 1967 Aug 12
Sunday, April 25, 2010
discussion (1967…)
• “In view of the similar response of the lung to a
variety of stimuli, a common mechanism of injury is
postulated. The loss of lung compliance, refractory
cyanosis, and microscopic atelectasis point to
alveolar instability as a likely source of trouble”.
• They postulated that surfactant dysfunction was a
significant contributor to alveolar collapse and
acknowledged that PEEP may be beneficial in
preventing atelectasis.
• but, “The use of PEEP merely buys time: unless the
underlying process can be successfully treated or
reversed the prognosis is grave”.
Ashbaugh DG, Bigelow DB, Petty TL, Levine BE
Acute respiratory distress in adults
Lancet, 1967 Aug 12
Sunday, April 25, 2010
y aquí empezó a usarse el PEEP…
Sunday, April 25, 2010
válvulas de umbral (threshold resistor)
presión = F / s
presión
flujo
Sunday, April 25, 2010
válvulas de umbral (threshold resistor)
presión = F / s
presión
flujo
Sunday, April 25, 2010
válvulas de flujo
presión = R x flujo
presión
flujo
Sunday, April 25, 2010
válvulas de flujo
presión = R x flujo
presión
flujo
Sunday, April 25, 2010
Falke KJ, et al.
J Clin Invest. 1972 Sep;51(9):2315-23.
Sunday, April 25, 2010
•
•
•
•
10 patients
Pa:FiO2<300 on ZEEP
Vt 8.9 to 24.1 ml/kg
ZEEP and PEEP 5, 10, and
15 cmH20
Falke KJ, et al.
J Clin Invest. 1972 Sep;51(9):2315-23.
Sunday, April 25, 2010
estudio internacional VM...
•
•
15.757 pac’s admitidos a 361 UCI’s en marzo 1998…
5.183 (33%) →VM x 6 días ( 31%)
•
231 (4,5%) pac’s SDRA ( 52%)
• pac’s
• PEEP, media±DS
mediana (rango)
• pac’s sin PEEP
día 1
231
8±4
8 (5-10)
34 (16%)
día 2
174
9±3
10 (6-12)
14 (8%)
Esteban A, et al. JAMA 2002; 287: 345-355.
Sunday, April 25, 2010
día 3
82
9±3
9 (5-12)
8 (10%)
estudio internacional VM...
•
•
15.757 pac’s admitidos a 361 UCI’s en marzo 1998…
5.183 (33%) →VM x 6 días ( 31%)
•
522 (10,1%) pac’s COPD ( 22%)
• pac’s
• PEEP, media±DS
mediana (rango)
• pac’s sin PEEP
día 1
522
5±2
5 (4-5)
218 (47%)
día 2
283
5±2
5 (5-6)
128 (45%)
día 3
85
6±3
5 (4-7)
33 (39%)
Esteban A, et al. JAMA 2002; 287: 345-355.
Sunday, April 25, 2010
los ventiladores de volumen
Sunday, April 25, 2010
ventilador de presión vs volumen
IN: t
LIM: P
CIC: P
Presión
(cmH2O)
Flujo
(lpm)
ventilador de
presión
Sunday, April 25, 2010
ventilador de
volumen
ventilador de presión vs volumen
IN: t
LIM: P
CIC: P
IN: t
LIM: V
Presión
(cmH2O)
Flujo
(lpm)
ventilador de
presión
Sunday, April 25, 2010
ventilador de
volumen
CIC: t
ventilador de presión vs volumen
IN: t
LIM: P
CIC: P
IN: t
LIM: V
Presión
(cmH2O)
Flujo
(lpm)
ventilador de
presión
Sunday, April 25, 2010
ventilador de
volumen
CIC: t
Diseño mecánico
(Harvard pump)
La duración del ciclo depende de
la velocidad del motor. La
inspiración y la espiración duran
lo mismo. El límite inspiratorio es
el volumen de desplazamiento del
pistón. Se puede agregar válvula
de escape para evitar
sobrepresión. La espiración es
activa (aspiración a presión
negativa).
gentileza Dr J. Urzúa
Sunday, April 25, 2010
Puritan Bennett MA-1
circa 1967
Sunday, April 25, 2010
Bear-1 (“flipper”)
circa 1975
Sunday, April 25, 2010
Sunday, April 25, 2010
ventilación convencional hacia 1980…
• 1960: VM en pacientes quirúrgicos sometidos a
anestesia y relajación muscular
– Vt 10-15 ml/Kg para prevención de atelectasias
• 1970: principios de manejo en SDRA
–
–
–
–
Vt 10-15 ml/Kg
PEEP 5-10-15... cmH2O
PVA ↑↑↑ (controladas, pero no restringidas)
atención en efectos HMD, FiO2 y barotrauma...
• incidencia barotrauma (macro)
– PVA 50 cmH2O → 50%
– PVA70 cmH2O → 80%
Sunday, April 25, 2010
Haake R, et al. Chest 1987; 91: 608.
barotrauma
15/01
Sunday, April 25, 2010
30/01
edema pulmonar producido por la ventilación con
presión (+) con altas presiones de inflación
14/0
45/0
Webb and Tierney. Am Rev Respir Dis 1974; 110:556-565.
Sunday, April 25, 2010
ventiladores de 3ª generación
Sunday, April 25, 2010
asistencia por presión
Presión
(cmH2O)
Flujo
(lpm)
ventilador de
presión
Sunday, April 25, 2010
ventilador
microprocesado
asistencia por presión
Presión
(cmH2O)
Flujo
(lpm)
ventilador de
presión
Sunday, April 25, 2010
ventilador
microprocesado
asistencia por presión
Presión
(cmH2O)
Flujo
(lpm)
ventilador de
presión
Sunday, April 25, 2010
ventilador
microprocesado
asistencia por presión
IN: t
LIM: P
CIC: P
IN: t-P
LIM: P
CIC: t-F
Presión
(cmH2O)
Flujo
(lpm)
ventilador de
presión
Sunday, April 25, 2010
ventilador
microprocesado
Siemens 900
circa 1982
Sunday, April 25, 2010
Puritan-Bennett 7200
circa 1984
Sunday, April 25, 2010
tiempos modernos
Sunday, April 25, 2010
Wilhelm Conrad Röntgen (1845-1923)
premio Nobel Física 1901
Allan M. Cormack (1924-1998)
Godfrey N. Hounsfield (1919-2004)
premio Nobel Medicina 1979
Sunday, April 25, 2010
mid 80’s: baby lung
Sunday, April 25, 2010
mid 80’s: baby lung
baby lung: lung surface in ARDS is small
→ main pathophysiologic principle for protective ventilation
Gattinoni L et al. Intensive Care Med 1986; 12: 137-142.
Gattinoni L & Pesenti A. Intensive Care Med 2005; 31: 776–784.
Sunday, April 25, 2010
baby lung
•
CT-scan study in ARDS:
4000
– densities 70-80% at ZEEP
– total volume N
– gas volume ↓↓↓
•
3000
2000
small lung: less surface
available for gas
exchange…
1000
normal
gas vo
weigh
0
ARDS
Gattinoni L et al. Intensive Care Med 1986; 12: 137-142.
Gattinoni
L & Pesenti A. Intensive Care Med 2005; 31: 776–784.
Gattinoni L et al, Anesthesiology
1987.
Sunday, April 25, 2010
baby lung
•
CT-scan study in ARDS:
4000
– densities 70-80% at ZEEP
– total volume N
– gas volume ↓↓↓
•
3000
2000
small lung: less surface
available for gas
exchange…
1000
normal
gas vo
weigh
0
ARDS
→ main pathophysiologic principle
for protective ventilation
Gattinoni L et al. Intensive Care Med 1986; 12: 137-142.
Gattinoni
L & Pesenti A. Intensive Care Med 2005; 31: 776–784.
Gattinoni L et al, Anesthesiology
1987.
Sunday, April 25, 2010
• retrospective case series
• 50 patients with severe ARDS (PaO2/FiO2 94)
– limited PIP by reducing Vt, allowing spontaneous breathing
with SIMV and disregarding hypercapnia.
– mean maximum PaCO2 was 62 mmHg (highest 129 mmHg
– hospital mortality was lower than that predicted by Apache II
(16% vs. 39.6%, chi 2 = 11.64, p<0.001).
Hickling KG, et al. Intensive Care Med. 1990;16(6):372-7.
Sunday, April 25, 2010
el gran salto
ventilación convencional
• normalizar gases arteriales
• VT elevados para prevenir
atelectasias…
Sunday, April 25, 2010
el gran salto
ventilación convencional
ventilación protectora
• normalizar gases arteriales
• VT elevados para prevenir
atelectasias…
• mecanoprotección
• limitar Vt y presiones
• CO2 secundario
Sunday, April 25, 2010
el gran salto
ventilación convencional
ventilación protectora
• normalizar gases arteriales
• VT elevados para prevenir
atelectasias…
• mecanoprotección
• limitar Vt y presiones
• CO2 secundario
la hipercapnia permisiva no es una modalidad
ventilatoria per se, sino una consecuencia de la
ventilación con bajo Vt en un pulmón con poca
superficie de intercambio (baby lung)
Sunday, April 25, 2010
the fact…!!!
Psycho (1960)
Sunday, April 25, 2010
the fact…!!!
mechanical
ventilation
ALI/ARDS
Psycho (1960)
Sunday, April 25, 2010
opening-closing
TNF-α
•
control
protective
LBA
44 pat‘s ARDS:
– Pa/fiO2 ~150
– LIS (Murray) 2.5
•
control group (n=19)
– TV 11.1 ml/Kg ®Ppl 31
cmH2O
– PEEP 6.5 cmH2O
– PaCO2 37.4 mmHg
•
IL-8
IL-6
protective strategy (n=18)
– TV 7.6 ml/Kg → Ppl 25
cmH2O
– PEEP 14.8 cmH2O
– PaCO2 46.9 mmHg
Ranieri VM et al. JAMA 1999; 282: 54-61.
Sunday, April 25, 2010
Sunday, April 25, 2010
• Brochard L, et al. AJRCCM 1998; 158: 1831-8.
– 108 pac, 25 centros, SDRA<72 horas, OSF=1
– low Vt: Pplat ≤25 cmH2O
– control: Vt ≥10 ml/Kg, Ppeak <60, PaCO2 38-42
Sunday, April 25, 2010
48%
41%
• Brochard L, et al. AJRCCM 1998; 158: 1831-8.
– 108 pac, 25 centros, SDRA<72 horas, OSF=1
– low Vt: Pplat ≤25 cmH2O
– control: Vt ≥10 ml/Kg, Ppeak <60, PaCO2 38-42
48%
41%
• Stewart TE, et al. N Engl J Med. 1998;338: 355-61.
– 120 pac SDRA<24 horas.
– low Vt: Vt ≤8 ml/Kg, Ppeak ≤30 cmH2O
– control: Vt 10-15, Ppeak <50 cmH2O
Sunday, April 25, 2010
48%
46%
• Brochard L, et al. AJRCCM 1998; 158: 1831-8.
– 108 pac, 25 centros, SDRA<72 horas, OSF=1
– low Vt: Pplat ≤25 cmH2O
– control: Vt ≥10 ml/Kg, Ppeak <60, PaCO2 38-42
48%
41%
• Stewart TE, et al. N Engl J Med. 1998;338: 355-61.
– 120 pac SDRA<24 horas.
– low Vt: Vt ≤8 ml/Kg, Ppeak ≤30 cmH2O
– control: Vt 10-15, Ppeak <50 cmH2O
48%
46%
• Brower R, et al. Crit Care Med. 1999; 27: 1492-8.
– 52 pac SDRA, algoritmo similar FiO2-PEEP.
– low Vt: Vt ≤8 ml/Kg, Pplat ≤30 cmH2O
– control: Vt 10-12, Pplat ≤50 cmH2O
Sunday, April 25, 2010
50%
46%
• Brochard L, et al. AJRCCM 1998; 158: 1831-8.
– 108 pac, 25 centros, SDRA<72 horas, OSF=1
– low Vt: Pplat ≤25 cmH2O
– control: Vt ≥10 ml/Kg, Ppeak <60, PaCO2 38-42
48%
41%
• Stewart TE, et al. N Engl J Med. 1998;338: 355-61.
– 120 pac SDRA<24 horas.
– low Vt: Vt ≤8 ml/Kg, Ppeak ≤30 cmH2O
– control: Vt 10-15, Ppeak <50 cmH2O
48%
46%
• Brower R, et al. Crit Care Med. 1999; 27: 1492-8.
– 52 pac SDRA, algoritmo similar FiO2-PEEP.
– low Vt: Vt ≤8 ml/Kg, Pplat ≤30 cmH2O
– control: Vt 10-12, Pplat ≤50 cmH2O
50%
46%
• Amato M, et al. NEJM 1998; 338: 347-354.
– 53 pac SDRA, algoritmo similar FiO2-PEEP.
– low Vt: curva P-V, Vt ≤4-6, PEEP 16, hipercapnia
– control: Vt 11-12, least PEEP (8-9), normocarbia
Sunday, April 25, 2010
38%
71%
Sunday, April 25, 2010
Sunday, April 25, 2010
Vt 6 ml/kg: mort 31%
Vt 12 ml/kg: mort 39%
Sunday, April 25, 2010
ARDS network: ¿fin de la historia?
Tobin MJ. Culmination of an era in research on the ARDS.
N Engl J Med 2000; 342: 1360–1361.
Sunday, April 25, 2010
ARDS network: ¿fin de la historia?
Tobin MJ. Culmination of an era in research on the ARDS.
N Engl J Med 2000; 342: 1360–1361.
→Vt 6 ml / kg… estándar en SDRA...
Sunday, April 25, 2010
clinical trials
Author Brochard'98
Stewart'98
Ranieri'99
Brower'99
Amato’98
ARDSnet'00
Kallet'05
Villar’06
ARDSnet'04
Mercat’08
Meade’08
Sunday, April 25, 2010
n
Protective Ppl PEEP Mort
108 120 44 52 53 861 292 95 549
767
983
25.7 10.7 48.0%
22.3 8.6 48.0%
24.6 14.8 38.0%
27.0 9.3 50.0%
31.8 16.3 38.0%
25.0 9.4 31.0%
27.5 10.0 32.0%
30.6 14.1 34.0%
low PEEP 24.0 9.1 24.9%
21.1 8.4 39.0%
24.9 10.1 40.4%
Control
Ppl PEEP Mort
p
31.7 10.7 41.0%
ns
26.8 7.2 46.0%
ns
31.0 6.5 58.0%
0.19
30.0 8.2 46.0%
ns
34.4 6.9 71.0% <0.001
33.0 8.6 39.8% 0.007
33.8 7.4 51.0% 0.004
32.6 9.0 55.5% 0.041
high PEEP
27.0 14.7 27.5%
ns
27.5 15.8 35.4%
ns
30.2 15.6 36.4%
ns
clinical trials
Author Brochard'98
Stewart'98
Ranieri'99
Brower'99
Amato’98
ARDSnet'00
Kallet'05
Villar’06
ARDSnet'04
Mercat’08
Meade’08
n
Protective Ppl PEEP Mort
108 120 44 52 53 861 292 95 549
767
983
25.7 10.7 48.0%
22.3 8.6 48.0%
24.6 14.8 38.0%
27.0 9.3 50.0%
31.8 16.3 38.0%
25.0 9.4 31.0%
27.5 10.0 32.0%
30.6 14.1 34.0%
low PEEP 24.0 9.1 24.9%
21.1 8.4 39.0%
24.9 10.1 40.4%
Control
Ppl PEEP Mort
31.7 10.7 41.0%
ns
26.8 7.2 46.0%
ns
31.0 6.5 58.0%
0.19
30.0 8.2 46.0%
ns
34.4 6.9 71.0% <0.001
33.0 8.6 39.8% 0.007
33.8 7.4 51.0% 0.004
32.6 9.0 55.5% 0.041
high PEEP
27.0 14.7 27.5%
ns
27.5 15.8 35.4%
ns
30.2 15.6 36.4%
ns
P distensión = P meseta - PEEP
Sunday, April 25, 2010
p
driving pressure (Pplateau - PEEP)
Sunday, April 25, 2010
driving pressure (Pplateau - PEEP)
Sunday, April 25, 2010
driving pressure (Pplateau - PEEP)
Sunday, April 25, 2010
driving pressure (Pplateau - PEEP)
Sunday, April 25, 2010
driving pressure (Pplateau - PEEP)
Sunday, April 25, 2010
driving pressure (Pplateau - PEEP)
Sunday, April 25, 2010
driving pressure (Pplateau - PEEP)
Sunday, April 25, 2010
safe zone
at risk…
driving pressure (Pplateau - PEEP)
Sunday, April 25, 2010
clinical data: low vs high PEEP
Author low PEEP n
Ppl PEEP Mort
high PEEP
(
max recruitment)
Ppl PEEP Mort
p
ARDSnet'04 549 24.0 9.1
25%
27.0 14.7 27%
ns
Mercat’08
767 21.1 8.4
31%
27.4 15.8
27%
ns
Meade’08
983
40%
27.0 13.5 36%
ns
Sunday, April 25, 2010
24.0 9.4
safe zone
at risk…
driving pressure (Pplateau - PEEP)
Sunday, April 25, 2010
high (15-16) vs low (9-10) PEEP
(1750 patients)
LOV study
Meade MO, et al. JAMA 2008
Express study
Mercat A, et al. JAMA 2008
Sunday, April 25, 2010
Meade and Mercat study: 1750 patients
low PEEP
890
high PEEP
860
20.7%
706
severe
hypoxemia
184
10.9%
severe
hypoxemia
94
Gattinoni L, Caironi P. JAMA 2008; 299: 691-3.
Sunday, April 25, 2010
766
Meade and Mercat study: 1750 patients
low PEEP
890
high PEEP
860
20.7%
severe
hypoxemia
184
706
S: 459
NS: 247
35.0%
S: 77
NS: 107
58.2%
10.9%
severe
hypoxemia
94
S: 37
NS: 57
60.6%
Gattinoni L, Caironi P. JAMA 2008; 299: 691-3.
Sunday, April 25, 2010
766
S: 514
NS: 252
32.9%
Meade and Mercat study: 1750 patients
low PEEP
890
high PEEP
860
20.7%
severe
hypoxemia
184
706
S: 459
NS: 247
S: 77
NS: 107
35.0%
58.2%
non-pulm
death
27.8%
pulmonary
death
12.0%
10.9%
severe
hypoxemia
94
S: 37
NS: 57
S: 514
NS: 252
60.6%
32.9%
pulmonary
death
6.6%
global
mortality
39.8%
Gattinoni L, Caironi P. JAMA 2008; 299: 691-3.
Sunday, April 25, 2010
766
global
mortality
35.9%
non-pulm
death
29.3%
concept: VILI is at first mechanical
overdistention
opening-closing
entilatory requirements
release of
mediators
increase in
permeability
• fem, 44 yo, pancreatitis
• 6 days on MV before transferred
• died
Pinhu L, et al. LANCET • Vol 361 • January 25, 2003
Fan E, Needham DM, Stewart TE. JAMA 2005; 294: 2889-96.
Sunday, April 25, 2010
concept: VILI is at first mechanical
barotrauma / volutrauma
overdistention
opening-closing
atelectrauma
entilatory requirements
release of
mediators
biotrauma
increase in
permeability
• fem, 44 yo, pancreatitis
• 6 days on MV before transferred
• died
Pinhu L, et al. LANCET • Vol 361 • January 25, 2003
Fan E, Needham DM, Stewart TE. JAMA 2005; 294: 2889-96.
Sunday, April 25, 2010
concept: VILI is at first mechanical
strain ⇒ Vt / EELV
barotrauma / volutrauma
overdistention
opening-closing
atelectrauma
entilatory requirements
release of
mediators
biotrauma
increase in
permeability
• fem, 44 yo, pancreatitis
• 6 days on MV before transferred
• died
Pinhu L, et al. LANCET • Vol 361 • January 25, 2003
Fan E, Needham DM, Stewart TE. JAMA 2005; 294: 2889-96.
Sunday, April 25, 2010
1667: Keeping a dog alive by blowing through its lungs with bellows
Hooke's law: the stress imposed on a solid is directly
proportional to the strain produced, within the elastic limit
Sunday, April 25, 2010
qué tienen en común?
Sunday, April 25, 2010
qué tienen en común?
su volumen corriente es 6 ml/kg…!!!
Sunday, April 25, 2010
Tenney SM and Remmers JE. Nature 1963; 197: 54-56,
Sunday, April 25, 2010
falla respiratoria severa
en cualquiera estrategia, el punto más
importante es limitar el volumen corriente a no
más de 6 ml/kg (peso ideal)
•
•
•
•
•
frecuencias respiratorias rápidas 30-35 /min
modalidad ventilatoria no afecta
protocolos sedación y analgesia
protocolos reanimación y depleción
control infecciones
Sunday, April 25, 2010
ventiladores de 4ª generación
Sunday, April 25, 2010
classic modes of ventilation
patient
output
patient
assistance
Sunday, April 25, 2010
input
physician
Vt - RR - I:E
FiO2 - PEEP
classic modes of ventilation
patient
output
input
patient
assistance
patient adapts to ventilator
Sunday, April 25, 2010
physician
Vt - RR - I:E
FiO2 - PEEP
close loop technology
patient
output
patient
assistance
patient
demand
Sunday, April 25, 2010
input
physician
inspiratory
support
FiO2 - PEEP
hipoxemia permisiva
Grocott MP, et al. N Engl J Med 2009; 360: 140-9.
Sunday, April 25, 2010
Sunday, April 25, 2010
21% mortality rate!!!
Sunday, April 25, 2010
historia VM
VPP
iron
lung
vent
presión
vent
volumen
PEEP
ventiladores
microprocesados
IMV
ventiladores
4a generación
PS
1950 1960 1970 1980 1990 2000 2010
SDRA
Sunday, April 25, 2010
usted
está
aquí
historia VM
VPP
iron
lung
vent
presión
vent
volumen
PEEP
ventiladores
microprocesados
IMV
ventiladores
4a generación
PS
1950 1960 1970 1980 1990 2000 2010
CT-scan
SDRA
Sunday, April 25, 2010
usted
está
aquí
historia VM
VPP
iron
lung
vent
presión
vent
volumen
PEEP
ventiladores
microprocesados
IMV
ventiladores
4a generación
PS
1950 1960 1970 1980 1990 2000 2010
CT-scan
pulmón
rígido
SDRA
Sunday, April 25, 2010
usted
está
aquí
historia VM
VPP
iron
lung
vent
presión
vent
volumen
PEEP
ventiladores
microprocesados
IMV
ventiladores
4a generación
PS
1950 1960 1970 1980 1990 2000 2010
CT-scan
pulmón
rígido
SDRA
Sunday, April 25, 2010
baby
lung
usted
está
aquí
historia VM
VPP
iron
lung
vent
presión
vent
volumen
PEEP
ventiladores
microprocesados
IMV
ventiladores
4a generación
PS
1950 1960 1970 1980 1990 2000 2010
CT-scan
pulmón
rígido
SDRA
Sunday, April 25, 2010
baby
lung
daño inducido
por la VM
usted
está
aquí
historia VM
VPP
iron
lung
vent
presión
vent
volumen
PEEP
ventiladores
microprocesados
IMV
ventiladores
4a generación
PS
1950 1960 1970 1980 1990 2000 2010
CT-scan
pulmón
rígido
SDRA
Sunday, April 25, 2010
baby
lung
ARDSnet
study
daño inducido
por la VM
usted
está
aquí
historia VM
VPP
iron
lung
vent
presión
vent
volumen
PEEP
ventiladores
microprocesados
IMV
ventiladores
4a generación
PS
1950 1960 1970 1980 1990 2000 2010
CT-scan
pulmón
rígido
SDRA
Sunday, April 25, 2010
baby
lung
ARDSnet
study
daño inducido
por la VM
usted
está
aquí
estrategia
protectora
objetivos de la VM... siglo XXI
• sostener la ventilación
• reclutar alvéolos colapsados
– mejorar intercambio
– ↓ trabajo ventilatorio
• evitar el daño inducido por la ventilación mecánica
– limitar presión transpulmonar
Sunday, April 25, 2010
principles of protective ventilation
Sunday, April 25, 2010
principles of protective ventilation
• limit Vt
– ↓ transpulmonary pressure
– no magic number…
Sunday, April 25, 2010
principles of protective ventilation
• limit Vt
– ↓ transpulmonary pressure
– no magic number…
• optimize PEEP
– optimize recruitment → mecánica, ↓Vd/Vt
– no magic number…
Sunday, April 25, 2010
principles of protective ventilation
• limit Vt
– ↓ transpulmonary pressure
– no magic number…
• optimize PEEP
– optimize recruitment → mecánica, ↓Vd/Vt
– no magic number…
• analgesia based sedation
– ↓ ventilatory drive
Sunday, April 25, 2010
principles of protective ventilation
• limit Vt
– ↓ transpulmonary pressure
– no magic number…
• optimize PEEP
– optimize recruitment → mecánica, ↓Vd/Vt
– no magic number…
• analgesia based sedation
– ↓ ventilatory drive
try the lung gently
Sunday, April 25, 2010
Bundles: prevención NAV
• No realizar cambios en circuito ventilatorio a menos
que esté específicamente indicado
• Higiene de manos estricto usando alcohol
• Staff apropiadamente educado y entrenado
• Incorporación de vacaciones de sedación y
protocolos de destete
• Aseo oral con clorhexidina
A European care bundle for prevention of ventilator-associated pneumonia.
Rello J. et al. Intensive Care Med 2009.
Sunday, April 25, 2010
Sunday, April 25, 2010
Sunday, April 25, 2010