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Pulmonary gas exchange in acute mountain sickness
Aviation, Space, and Environmental Medicine
|October 1, 1976
Summary
Healthy volunteers at high altitude experienced acute mountain sickness (AMS), with severity linked to blood gas changes. Cerebral and pulmonary dysfunction appeared to develop simultaneously, suggesting coexisting edema.
Area of Science:
- Altitude physiology
- Respiratory medicine
- Neurology
Background:
- Acute mountain sickness (AMS) is a common condition affecting individuals ascending to high altitudes.
- Understanding the physiological mechanisms underlying AMS severity is crucial for prevention and treatment.
Purpose of the Study:
- To investigate the relationship between blood gas levels and the clinical severity of AMS in healthy volunteers.
- To explore the development of gas exchange abnormalities and their correlation with cerebral symptoms at high altitude.
Main Methods:
- Healthy volunteers were airlifted to 5,360 m.
- Blood gases were measured at 2,990 m and 5,360 m.
- Clinical AMS symptoms and severity were assessed.
Main Results:
- All subjects exhibited AMS symptoms, varying in severity.
- AMS severity correlated directly with arterial PCO2 and inversely with pH.
- PO2 decreased over 48 hours in severe AMS cases, with increased alveolar-arterial PO2 difference and venous admixture ratio.
- These gas exchange abnormalities coincided with marked cerebral symptoms.
Conclusions:
- Clinical AMS severity is linked to arterial PCO2 and pH, not initial PO2.
- Gas exchange abnormalities and cerebral symptoms at high altitude may indicate simultaneous pulmonary and cerebral edema.
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