Enhancement of preoxygenation for decompression sickness protection: effect of exercise duration.
Aviat Space Environ Med
; 73(12): 1161-6, 2002 Dec.
Article
em En
| MEDLINE
| ID: mdl-12498543
ABSTRACT
INTRODUCTION:
Since strenuous exercise for 10 min during preoxygenation was shown to provide better protection from decompression sickness (DCS) incidence than resting preoxygenation, a logical question was would a longer period of strenuous exercise improve protection even further?HYPOTHESIS:
Increased strenuous exercise duration during preoxygenation increases DCS protection.METHODS:
There were 60 subjects, 30 men and 30 women, who were exposed to 9,144 m (4.3 psia) for 4 h while performing mild, upper body exercise. Before the exposures, each subject performed three preoxygenation profiles on different days in balanced order a 90-min resting preoxygenation control; a 240-min resting preoxygenation control; and a 90-min preoxygenation including exercise during the first 15 min. The subjects were monitored at altitude for venous gas emboli (VGE) with an echo-imaging system and observed for signs and symptoms of DCS.RESULTS:
There were no significant differences in occurrence of DCS following any of the three preoxygenation procedures. Results were also comparable to an earlier report of 42% DCS with a 60-min preoxygenation including a 10-min exercise. There was no difference between VGE incidence in the comparison of protection offered by a 90-min preoxygenation with or without 13 min of strenuous exercise. The DCS incidence following a 240-min resting preoxygenation, 40%, was higher than observed during NASA studies and nearly identical with the earlier 42% DCS after a 60-min preoxygenation including exercise during the first 10 min.CONCLUSION:
The protection offered by a 10 min exercise in a 60-min preoxygenation was not increased with extension of the preoxygenation exercise period to 15 min in a 90-min preoxygenation, indicating an upper time limit to the beneficial effects of strenuous exercise.Palavras-chave
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxigenoterapia
/
Exercício Físico
/
Doença da Descompressão
Tipo de estudo:
Clinical_trials
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Aviat Space Environ Med
Ano de publicação:
2002
Tipo de documento:
Article