Accession Number : AD0756263

Title :   Decompression Disorders after Exposure to 'Safe Pressure' or 'Safe Altitude',

Corporate Author : DEFENCE RESEARCH INFORMATION CENTRE ORPINGTON (ENGLAND)

Personal Author(s) : Elinskii,M. P.

Report Date : JAN 1973

Pagination or Media Count : 9

Abstract : From experimental studies and clinical observations cited, it is clear that decompression starting from 2.25 atm abs or less and also ascents to an altitude of less than 8000 m may lead to the appearance of gas bubbles in the blood and sometimes cause severe decompression sickness. Such cases are probably not always spotted because of the widely held view that disorders do not occur with such pressure drops. The problem raised in this paper seems to be of practical importance because if decompression sickness may arise after exposure to a depth of 12.5 m, this points to the formation of gas bubbles large enough to cause embolism. From this it follows that uninterrupted ascent from these depths is not always harmless, particularly as 'occult' gas bubbles may be formed leading to subclinical forms of decompression sickness. In the second place saturation of the organism with nitrogen and other gases at a pressure of 2.25 atm abs may not be taken as an index of safe supersaturation - both now and hitherto calculations of tables for stepwise decompression are based on the assumption that a pressure drop in the ratio of 2.25:1 does not cause disease. It is possible that the need to reduce the factor with increasing depths is primarily due to a false concept of the complete safety of ascending from a depth of 12.5 m.

Descriptors :   (*DECOMPRESSION SICKNESS, PATHOLOGY), GAS EMBOLISM, DIVING, STRESS(PHYSIOLOGY), BAROMETRIC PRESSURE, ALTITUDE, USSR

Subject Categories : Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE