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Do changes in lung function predict high-altitude pulmonary edema at an early stage?
Oliver Senn1, Christian F Clarenbach, Manuel Fischler
1Pulmonary Division, University Hospital of Zurich and Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
Medicine and Science in Sports and Exercise
|September 9, 2006
Summary
Rapid high-altitude ascent alters lung function, suggesting fluid accumulation but not increased pulmonary pressure. Individual responses vary and don't predict high-altitude pulmonary edema (HAPE).
Area of Science:
- Physiology
- Altitude Medicine
- Pulmonary Function
Background:
- High altitude exposure causes lung function changes.
- Mechanisms and links to high-altitude pulmonary edema (HAPE) are debated.
Purpose of the Study:
- Investigate pulmonary function changes over time.
- Correlate lung function with hemodynamics and symptoms during rapid ascent.
Main Methods:
- Assessed spirometry, nitrogen washout, diffusing capacity (DLCO), and Doppler echocardiography.
- 26 unacclimatized subjects ascended to 4559 m.
- Measurements taken at 490 m and 4559 m.
Main Results:
- Vital capacity (FVC) decreased; FEV1/FVC and closing volume increased at high altitude.
- Elevated closing volume correlated with lower DLCO, not pulmonary artery pressure.
- No subjects developed overt HAPE.
Conclusions:
- Pulmonary function changes suggest interstitial fluid accumulation.
- No link found between lung function changes and pulmonary artery pressure.
- Individual responses to altitude vary and do not predict HAPE.
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