Document Detail


Oxygen consumption at altitude as a risk factor for altitude decompression sickness.
MedLine Citation:
PMID:  21043293     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
INTRODUCTION: The existence of a general influence of exercise on the incidence of decompression sickness (DCS) has been known for more than a half-century. However, quantification of the effect has not been done for several reasons, including isolation of exercise as the only variable. The DCS database at Brooks City-Base, TX, contains detailed physiologic information on over 3000 altitude exposures. The purpose of this study was to measure Vo2 during the activities performed during those exposures to retrospectively determine if Vo2, a quantifiable index of exercise intensity, was related to the level of reported DCS.
METHODS: Ground-level activity was designed to duplicate the standardized activity during the altitude exposures. Breath-by-breath Vo2 was determined for each activity using a COSMED metabolic measurement system. Comparison of the Vo2 during four levels of activity performed under otherwise comparable conditions allowed a determination of correlation between Vo2 and DCS risk observed during the altitude exposures.
RESULTS AND DISCUSSION: Four previous altitude exposure profiles at 8992 m to 9144 m (29,500 to 30,000 ft; 231 to 226 mmHg) for 4 h following a 1-h prebreathe resulted in 38-86% DCS. This study provided the Vo2 of activities during those studies. The correlation between DCS incidence and the highest 1-min Vo2 of activity was 0.89.
CONCLUSION: The highest 1-min Vo2 showed a high correlation with level of DCS risk. Future exposures involving lower levels of activity could provide data that would allow improvement in modeling of DCS risk.
Authors:
James T Webb; Larry P Krock; Michael L Gernhardt
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Aviation, space, and environmental medicine     Volume:  81     ISSN:  0095-6562     ISO Abbreviation:  Aviat Space Environ Med     Publication Date:  2010 Nov 
Date Detail:
Created Date:  2010-11-03     Completed Date:  2010-11-30     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7501714     Medline TA:  Aviat Space Environ Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  987-92     Citation Subset:  IM; S    
Affiliation:
NASA Johnson Space Center, Houston, TX, USA. jtwebb@swbell.net
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MeSH Terms
Descriptor/Qualifier:
Adult
Aerospace Medicine
Altitude Sickness / prevention & control
Decompression Sickness / etiology*,  physiopathology*
Exercise / physiology*
Humans
Male
Oxygen Consumption / physiology*
Oxygen Inhalation Therapy / adverse effects*
Young Adult

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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