From The Headache Mountains To The Pyramid Lab: Research At

From the Headache Mountains to the Pyramid Lab:
Research at High Altitude
Rovereto 10 dicembre 2013
Annalisa Cogo
Centro Studi Biomedici Applicati allo Sport
Università di Ferrara
Mountain Environment
Barometric Pressure
↓
PiO2
↓
Air Density
↓
Temperature
↓
Humidity
↓
Wind
↑
Allergens
↓
Pollution
↓
Barometric Pressure and PIO2 at increasing altitude
Ventilation ↑
Heart rate
↑
Pulmonary
pressure
↑
The compensatory responses of the human body as well as the
development of acute mountain sickness are related to the level of
hypoxemia.
The human response to hypoxia is characterised by systemic changes in
respiratory, cardiovascular and haematopoietic physiology that
combine to restore adequate oxygenation.
High Altitude and Ventilation
Ventilation during Exercise at SL e HA
10 M age 25-66, 4°
° day at 4559m,
Max Incremental Exercise 30watt/min
3.0
120
sl
V'O2 (L/min )
Ventilation (L/min)
100
Optoelectronic
Plethysmography (OEP
2.5
System, BTS, Milan, Italy)
to measure VE, TV, RR
2.0
without mouthpiece
80
1.5
60
1.0
40
high altitude
sea level
0.5
20
100
Arterial oxygen saturation (SaO 2)
HA
140
sl
95
90
85
HA
80
75
rest
0
70
0.0
0
20
40
60
80
Workload (%WMAX,SL)
100
0
20 40 60 80 100 120 140 160
Ventilation (L/min)
20
40
60
80 100 120 140
Ventilation (L/min)
Aliverti et al Respir Physiol Neurobiol 2011
The Lung at Altitude
The lung is the interface between the environment and the metabolic function of the
body and plays a pivotal role in the acclimatization process.
However, it may also be involved in maladaptive responses.
“I am nothing more than a single, narrow,
gasping lung, floating over the mists and
summits”
” (R.Messner)
Altitude Classification
0-500 m Near Sea Level
500-2000m Low Altitude
2000-3000m Moderate Altitude
No altitude-related effects on well-being or
athletic performance
No altitude-related effects on well-being but
relevant impairment of performance
possible, particularly in highly trained
athletes > 1500 m. This can be overcome
completely by acclimatization.
Effects of altitude on well-being in nonacclimatized subjects with minor sleep
disturbances or symptoms of AMS may occur
after ≥ 9 hours of exposure.
Discomfort is transient during the first days.
Maximum aerobic performance
↓significantly but can be restored largely by
acclimatization. Significant erythropoietic
response occurs within 3–4 weeks.
(Bartsch & Saltin Scand J Med Sci Sport 2008)
3000-5500 High Altitude AMS occurs in a large number of non-acclimatized
individuals during the first days of exposure.
Susceptible individuals may develop HAPE >
3000 m a.s.l. and HACE > 4000 m a.s.l.
Staged ascent is recommended to avoid
these
illnesses. The altitude will significantly reduce
athletic performance even after full
acclimatization.
> 5500mExtreme Altitude 5500 m a.s.l. appears to be the ceiling for longterm adaptation in humans, as the highest
permanent settlements are at this altitude
Acute Mountain Sickness
Too High Too Fast
When people who live near sea level go to altitudes > 25003000m many develop symptoms of acute mountain sickness.
Mild
Severe
Headache, fatigue, lightheadedness, loss of
appetite, insomnia, and sometimes dizziness,
palpitations, nausea
Pulmonary Edema (HAPE)
Cerebral Edema (HACE)
The first reference to mountain sickness is in a classical Chinese history of the period
preceding the Han dynasty (about 30 B.C.E)
“..on passing the Great Headache Mountain, the Little Headache Mountain, The Red
Pass and the Fever Slope, men’s bodies become feverish, they lose colour and area
attacked with headache and vomiting: the cattle being in like condition”
The most celebrated early account of acute mountain sickness was by Father Jose de
Acosta who traveled from Spain to Peru as a Jesuit missionary in about 1570.
Following Acosta’s account, there were
many anedoctal reports of
disagreeable sensations in travelers to
HA. An excellent compendiums is Paul
Berts’ book where the first chapter
chronicles various mountain ascents all
over the world and corresponding
reports of mountain sickness
Angelo Mosso 1846-1910
Fisiologo all’Università di Torino
Punta Gnifetti al Monte Rosa prima e
dopo la costruzione della
Capanna Regina Margherita
(foto Vittorio Sella)
4 settembre 1893
si inaugura la Capanna Regina Margherita a 4559m sulla Punta Gnifetti del
Monte Rosa.
The Pyramid Laboratory, 5050m, Khumbu Valley, Nepal
1. AMS and the ascent rate
Prevalence of AMS at Capanna Regina Margherita (4559m) in susceptible and nonsusceptible subjects according to the rate of ascent and pre-expousre to HA
Schneider 2005
Slow Ascent
# HAPE at 4559
HAPE x 4
Rate of ascent.
330m/die
14 d. 3500-4000m
HAPE x 3
HAPE x 2
Max Altitude
6990m
6400m
350m/die
5170m
350m/die
5170m
365m/die
5800m
365m/die
5800m
14 d. 2700m-6900m
6900m
2. The Hypoxic Profile at HA
O2 at HA
Capanna Regina Margherita 4559m
10 males, age 25-66, 4°
° day at 4559m, 6°
° day >3500
pH
PaCO2
PaO2
BE
HCO3
SaO2
7.46
27.2mmHg
46.3mmHg
-4.5
19.3
84.5
Pa O2
53-37mmHg
PaCO2 31.6-23.9 mmHg
SaO2 during incremental test 30 Watt/min
#10
BASE
87
30W
85,2
60W
82,9
90W
81,1
120
80
#9
#7
#2
150
76,9
180
73
210
68
To investigate the daily hypoxic scenario by monitoring oxygen
saturation for 24 hours at different altitudes during the trek to Pyramid
Laboratory (2600-5050m)
5500
N
5000
4500
N
Altitude (m)
4000
N
3500
3000
N
N
N
N
N
N
N
N
2500
2000
1500
1000
1
2
3
4
5
6
7
Nights (N)
8
9
10
11
12
13
Instrument
SpO2 was measured using a
battery powered, recording
pulse oximeter equipped with a
finger probe with 24-hour data
memory.
At the end of each monitoring
period the data were
transferred from the portable
equipment to the hard drive of
a computer.
Pulsox-3Si,Minolta
Pomidori L. et al HAM&B 2009
100
Day
Night
lowest day
p = 0.03
90
lowest night
p = 0.01
p = 0.025
80
Sa
O2
%
70
60
50
40
2800m-3500m
3500m
3800m-4200m
4200m
5050m
Pomidori L. et al HAM&B 2009
Desaturations
Pomidori L. et al HAM&B 2009
During standardized exercise, the oxygen desaturation decreased
3500m
4200m
5050m
10.6%
13.4%
11.3%
At 4200 and 5050 m, the percentage of decrease was significantly
higher than at 3500m ( p<0.03).
Pomidori L. et al HAM&B 2009
CONCLUSION
At each altitude the mean value measured during 24-hour monitoring is
always significantly lower than the value measured during the 3 minutes
observation.
The time spent with oxygen saturation ≤90% increases with altitude.
A significantly lower saturation is found during the night at each altitude
and the difference between day and night values is always significant.
At 4200m and 5050m the % oxygen desaturation during exercise is
significantly higher than at 3500.
3. Ventilation, Ventilatory Pattern, Thoraco-Abdominal Coordination
A deeper and slower ventilation (yoga derived breathing) is more efficient in
terms of gas exchange and has been reported
• to improve resting gas exchange in heart failure patients (Bernardi L, 1998)
• to improve gas exchange and thoraco-abdominal coordination in COPD
(Pomidori L, 2009)
• to maintain a satisfactory oxygenation during hypoxic exposure (Bernardi L,
2001, 2007)
Lifeshirt system (VivoMetrics, CA, USA)
O2 saturation
ECG
Sensors on Rib cage and Abdomen VE,
ventilatory pattern and time, Thoraco
abdominal coordination
7 élite climbers (M age32-52)
1°
° day at the Everest North base Camp 5300m
They hiked along a standardized trail around the base
camp. The speed, the slope and the difference in height
were monitored by means of a GPS
Pomidori L, Cogo A, work in progress
SL
BC
RESULTS
20
18
16
Phase
angle
cb1 max PhAng
Phase Angle
Regression Plot
20
14
12
Φ °
15
*p<0,05
10
8
10
6
ns
4
5
2
2
0
Rest
Exercise
At HA:
Significant correlation between
Φ and ∆ SpO2% (rest-exercise
4
6
8
10
12
delta sat
Y = 5,955 + ,532 * X; R^2 = ,544
14
16
∆ SpO2%
∆∆
∆ SpO2% =
SpO2 rest vs SpO2 exercise
18
20
We analysed VE, ventilatory pattern (VT, BR, VE/VT), thoraco-abdominal
coordination (phase angle [PhA]), and oxygen saturation (SpO2) in Skyrunners
during a race simulation.
14 Skyrunners (12M; age 34-60) run from 2030m to 2804m wearing an
inductive pletismography system (Lifeshirt) equipped with a pulse-oximeter
and GPS (Garmin).
Subjects run 6.2km, mean speed 1.6m/s.
r 0.3
Slope %
The relationship between
the slope (S) and PhA is
represented by a
quadratic curve.
As S increases >30% an
increase in PhA is
observed, index of
thoraco-abdominal
coordination (p<0.01) .
The decrease in PhA is significantly related to a
decrease in SpO2. p < 0.01
R 0.697
For slopes >20% the increas in PhAng is
significantly related to an increase in
VE/VT (r 0.406*)
An increase in VE/VT is significantly
correlated to a decrease in SpO2
(r - 0.69*).
The lower SpO2 is associated to a
lower race speed (r 0.33*), more
evident when the slope is > 20%.
*p<0.01
Conclusion
During mountain race the slope of the ground negatively influences
the thoraco-abdominal coordination, mostly when slope is >30%.
The increase in slope is also related to a decrease in SpO2 through a
change in ventilatory pattern toward a less efficient breath.
These factors negatively influence the speed of the performance.
QUESTION? Is it possible to train the ventilatory pattern?
Indoor Pollution and Health
SHARE-EVK2CNR Project
We study a particular sample of population
living in the Khumbu Valley in Nepal.
In this valley there are no roads, no
industries
( = no traffic and industry pollution) ,
very low smoke habit (3%)
( = no counfounding factors)
but the population uses biomass fuels for
home heating and cooking and many
houses have no chimney
( = very high indoor pollution).
Environmental CO vs Exhaled CO
r 0.4
p = 0.0001
20
10
Ventilation Index vs Exhaled CO
0
0
20
40
60
CO espirato
0.3
r 0.3
p = 0.0019
0.2
ρ e [m-1]
CO ambientale
30
0.1
0.0
0
20
40
CO ex
60
Risk of environmental CO >5ppm is significantly higher in the buildings
with open fire
Cappa tradizionale / nessuno scarico
Unadjusted OR
Cappa tradizionale / nessuno scarico
Adjusted OR
1991
Lukla Airport 2800mt
2011
The bridges over the river Dud Koshi
1991
2011
Pomidori L et al. J Cardiopulm Rehabil Prev. 2009
Bernardi L et al. J Hypertens. 2001
Bernardi L et al. Eur J Appl Physiol. 2007
9000
AL
ALTITUDES
8500
KU
MM
KU
SM
O2
GG
8000
7500
TB
SD
7000
6500
SUBJECTS
SM
GM
Bernardi L et al ERJ 2006