EFFECTS OF REPEATED EXPOSURE INERT GAS NARCOSIS ON SUBJECTIVE AND OBJECTIVE MEASURES OF IMPAIRMENT

Authors
  1. Hamilton, K.
  2. Laliberte, M-F.
  3. Heslegrave, R.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN)
Abstract
Within the diving community there is a persevering view that impairment due to nitrogen narcosis can be reduced significantly by repeating air dives on successive days. However, laboratory studies have failed to support the notion that performance impairment is lessened with repeated air diving. Since anecdotal reports concerning adaption to narcosis are based on subjective estimates of impairment and not on objective measures of performance, the lack of objective support for adaption may be due to differential changes in subjective and objective measures with repeated exposure to narcosis. To examine this possibility, eleven divers were exposed to narcosis. To examine this possibility, eleven divers were exposed to a narcosis and control condition daily for five successive days. The narcosis condition involved breathing air in a dry recompression chamber at 54.6 m. The control was conducted at 3.0 m during the final stages of decompression. Subjective estimates of impairment were assessed using a 9-point narcosis scale. Objective performance was measured using a three choice serial reaction time task. The results indicated that subjective estimates of narcosis decreased over the 5 days without improvement on reaction time relative to the control. Subjective adaption without parallel performance improvement could lead to overconfidence and, in turn, jeopardize safety. TRUNCATED.
Report Number
DCIEM-91-60 —
Date of publication
01 Jun 1991
Number of Pages
11
DSTKIM No
94-04198
CANDIS No
143092
Format(s):
Hardcopy;Originator's fiche received by DSIS

Permanent link

Document 1 of 1

Date modified: