RESPIRATORY FUNCTION STUDIES DURING PROLONGED EX POSURE TO SIMULATED ALTITUDE WITHOUT HYPOXIA,
Abstract
This report deals with respiratory function stud ies (total and timed vital capacity, maximum breathing capacity, and expiratory minute volume) made during several space cabin simulator experi ments at ground level and at simulated altitudes of 18,000 feet, 27,000 feet, and 33,500 feet. The duration of the experiments was from 14 to 30 days with a PO sub 2 from normal level to 243 mm. Hg. A reduction in forced vital capacity was noted throughout the experiments at simulated al titude with a prompt reduction at the onset of exposure. Timed vital capacity showed that the percentage of the FVC expired during the first second of effort was greater at 33,500 feet than at ground level with intermediate values at 27,000 feet and 18,000 feet, respectively. An increase in maximum breathing capacity was seen at altitude; the magnitude of the changes appears to be due to the increase in simulated altitude and the decreased density of the respired gas. The expiratory minute volume does not appear to change during exposure to altitude as compared with ground control. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1963
- Accession Number
- AD0417649
Entities
People
- Billy E. Welch
- Frode Ulvedal
- Ralph Garr Cutler
- Thomas E. Morgan Jr.
Organizations
- United States Air Force School of Aerospace Medicine