Accession Number:

ADP011091

Title:

Altitude Decompression Illness - The Operational Risk at Sustained Altitudes up to 35,000 ft.

Descriptive Note:

Corporate Author:

DEFENCE EVALUATION AND RESEARCH AGENCY FARNBOROUGH (UNITED KINGDOM) CENTRE FOR HUMAN SCIENCES

Personal Author(s):

• Lee, V. M.
• Hay, A. E.

Report Date:

2001-06-01

Pagination or Media Count:

14.0

Abstract:

Altitude decompression illness DCI is generally considered to be a risk at altitudes in excess of 18,000 ft. UK military aircrew are therefore not routinely exposed to altitudes in excess of this, however, there are circumstances such as loss of cabin pressure, parachute operations, and high cabin altitudes in future aircraft, when exposure to altitudes in excess of 18,000 ft may be necessary. A series of experiments were carried out at the DERA Center for Human Sciences to investigate the risk of venous gas emboli VGE and DCI symptoms at altitudes up to 35,000 ft. Subjects were exposed, for a maximum of four hours, to 1 simulated altitudes between 20,500 ft and 25,000 ft breathing an oxygennitrogen gas mixture, 2 25,000 ft breathing 100 oxygen with and without one hour of prior denitrogenation and 3 simulated altitudes up to 35,000 ft with one hour prior denitrogenation. It was concluded that VGE formation will occur at cabin altitudes that will be encountered by aircrew of future agile aircraft although only 7 of subjects developed symptoms.

Descriptors:

• *DECOMPRESSION SICKNESS
• SIMULATION
• SYMPOSIA
• RISK
• FLIGHT CREWS
• NITROGEN
• OXYGEN
• PRESSURE
• HIGH ALTITUDE
• EXPOSURE(PHYSIOLOGY)
• RESPIRATION
• VEINS
• GAS EMBOLISM
• ALTITUDE SICKNESS
• UNITED KINGDOM

Subject Categories:

• Medicine and Medical Research
• Stress Physiology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE