Voluntary Hyperventilation into a Simple Mixing Chamber* Relieves High Altitude Hypoxia

Gilbert D. Saul, Wayne J. Lukina, Steven C. Brakebush, Denny E. Wilmot, and Bruce R. Tammelin
Aviat Space Environ Med 2002; 73:404-7

Abstract

Involuntary hyperventilation is a critical factor in acclimatization to a high altitude. Unacclimatized subjects do poorly when acutely exposed to high altitude. This may not be due to hypocapnia itself, but rather an associated symptom which inhibits hypoxic respiratory stimulation. In an unacclimatized individual, voluntary hyperventilation may greatly relieve hypoxia and may be an alternative to involuntary hyperventilation. However, subjects voluntarily hyperventilating may overventilate and become disabled from severe hypocapnia. A simple mixing chamber is described which makes voluntary hyperventilation easier, safer, and possibly more effective. A subject breathing into a mixing chamber was able to maintain an SaO₂ of 90% at 20,000 ft.

Keywords: voluntary hyperventilation, high altitude, hypoxia, hypocapnia, mixing chamber.

*U.S. patent No. 5,647,345

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Table of Contents for Volume 73, Number 4 of the ASME journal.