Accession Number:

ADA275261

Title:

Decompression Sickness Risk Versus Time and Altitude

Descriptive Note:

Interim rept. Nov 1992-NOV 1993

Corporate Author:

KRUG LIFE SCIENCES SAN ANTONIO TX SAN ANTONIO DIV

Personal Author(s):

Report Date:

1993-11-01

Pagination or Media Count:

6.0

Abstract:

To predict altitude decompression sickness DCS risk with any degree of accuracy, one must weigh variables such as prebreathe time, rate of ascent descent, time at altitude, altitude, mixed breathing gas dependent upon altitude, and profiles with multiple ascents and descents. The length of research chamber exposures is fixed. Therefore, risk assessment is based on DCS incidence after this fixed period at simulated altitude. From an operational standpoint, variable time at altitude complicates any predictive capability, although a computer model to handle all of these variables is in development. In the interim, a retrospective study from the Armstrong Laboratory Decompression Sickness Research Database has produced risk curves which can be used to predict DCS or venous gas emboli VGE incidence as a function of time at various altitudes. We limited the data to 1 zero-prebreathe exposures to less than 20,000 ft breathing 50 O2, 50 N2 2 zero-prebreathe exposures to less than 20,000 ft breathing 100 O2 and 3 1-h prebreathe exposures to greater than 20,000 ft breathing 100 02. Using the curves, one can select a timealtitude of exposure and estimate the DCS and VGE percentage. Decompression sickness, Venous gas emboli, Prebreathe, Latency.

Subject Categories:

  • Medicine and Medical Research
  • Inorganic Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE