NITROGEN AND HELIUM AS FACTORS AFFECTING DECOMPRESSION STRESS SEVERITY,
Abstract
Endocrine-metabolic appraisal was made by means of a battery of urinary determinations in three experiments in which human volunteers were exposed to sequential changes in pressure and composition of the gaseous environment. In each test, there was exposure to a two-gas environment, either 46% oxygen - 50% nitrogen or 46% oxygen - 50% helium, with ambient pressure at 7 p.s.i.a. The objective was to quantify stress effects of the diluent gases, helium and nitrogen. Nonspecific stress was detected in each experiment, the sum of the deviations from control levels for ten urinary variables (including norepinephrine, epinephrine, 17-hydroxycorticosteroids, various electrolytes, and certain nitrogenous metabolites) serving to differentiate the effects of the different diluent gases. When the duration of exposure to the different two-gas environments was only 4 hours and there was brief, subsequent exposure to 3.5 p.s.i.a. (breathing 100% oxygen), nitrogen appeared to be the stronger stressor; with duration increased to 12 hours, helium was judged to be the stronger stressor. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1968
- Accession Number
- AD0676133
Entities
People
- Edgar W. Williams
- Henry B. Hale
Organizations
- United States Air Force School of Aerospace Medicine