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 PiO 2 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 physiologythat 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 Ventilation (L/min) 140 120 100 80 60 40 20 0 rest HA sl V'O2 (L/min) Optoelectronic Plethysmography (OEP 3.0 2.5 System, BTS, Milan, Italy) to measure VE, TV, RR without mouthpiece 2.0 1.5 1.0 0.5 0.0 high altitude sea level Arterial oxygen saturation (SaO 2 ) 100 95 90 85 80 75 70 sl HA 0 20 40 60 80 100 0 20 40 60 80 100 120 140 160 20 40 60 80 100 120 140 Workload (%W MAX,SL ) Ventilation (L/min) 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 No altitude-related effects on well-being or athletic performance 500-2000m Low Altitude No altitude-related effects on well-being but relevant impairment of performance possible, particularly in highly trained athletes > 1500m. This can be overcome completely by acclimatization. 2000-3000m Moderate Altitude 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 > 3000ma.s.l. and HACE>4000ma.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 > 2500-3000m 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 Rate of ascent. Max Altitude HAPE x 4 330m/die 6990m 14 d. 3500-4000m 6400m HAPE x 3 350m/die 5170m 350m/die 365m/die 365m/die 5170m 5800m 5800m HAPE x 2 14 d. 2700m-6900m 6900m
2. The Hypoxic Profile at HA
O 2 at HA Capanna Regina Margherita 4559m 10 males, age 25-66, 4 day at 4559m, 6 day >3500 ph PaCO 2 PaO 2 BE HCO3 SaO 2 7.46 27.2mmHg 46.3mmHg -4.5 19.3 84.5 Pa O2 53-37mmHg PaCO2 31.6-23.9 mmhg
SaO 2 during incremental test 30 Watt/min #10 #9 #7 #2 BASE 30W 60W 90W 120 150 180 210 87 85,2 82,9 81,1 80 76,9 73 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) Altitude (m) 5500 5000 4500 4000 3500 3000 2500 2000 1500 1000 N N N N N N N N N N N 1 2 3 4 5 6 7 8 9 10 11 12 13 Nights (N)
Instrument SpO 2 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
Sa O2 % 100 90 80 70 p = 0.03 p = 0.01 p = 0.025 Day Night lowest day lowest night 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)
O2 saturation ECG Sensors on Rib cage and Abdomen VE, ventilatory pattern and time, Thoraco abdominal coordination Lifeshirt system (VivoMetrics, CA, USA)
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
Φ 20 15 10 5 0 Phase Angle *p<0,05 ns Rest Exercise SL BC Phase angle 20 18 16 cb1 max PhAng 14 12 10 8 6 4 2 Regression Plot RESULTS 2 4 6 8 10 12 14 16 18 20 delta sat Y = 5,955 +,532 * X; R^2 =,544 SpO2% At HA: Significant correlation between Φ and SpO2%(rest-exercise SpO2% = SpO2 rest vs SpO2 exercise
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.
r0.3 Slope% The relationship between the slope (S) and PhAis represented by a quadratic curve. As S increases >30% an increase in PhAis observed, index of thoraco-abdominal coordination (p<0.01). The decrease in PhA is significantly related to a decrease in SpO2. p < 0.01
For slopes >20% the increas in PhAng is significantly related to an increase in VE/VT (r 0.406*) R0.697 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 ventilatorypattern toward a less efficient breath. Thesefactorsnegativelyinfluencethe speedof 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 30 r 0.4 p = 0.0001 CO ambientale 20 10 0 0 20 40 60 CO espirato 0.3 Ventilation Index vs Exhaled CO r 0.3 p = 0.0019 0.2 ρe [m-1] 0.1 0.0 0 20 40 60 CO ex
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 KU MM TB 8500 KU SM ALTITUDES 8000 7500 GG SD SM GM O 2 7000 6500 SUBJECTS
Bernardi L et al ERJ 2006