Document Detail

PH2O and simulated hypobaric hypoxia.
MedLine Citation:
PMID:  22195399     Owner:  NLM     Status:  MEDLINE    
Some manufacturers of reduced oxygen (O2) breathing devices claim a comparable hypobaric hypoxia (HH) training experience by providing F1O2 < 0.209 at or near sea level pressure to match the ambient oxygen partial pressure (iso-PO2) of the target altitude. I conclude after a review of literature from investigators and manufacturers that these devices may not properly account for the 47 mmHg of water vapor partial pressure that reduces the inspired partial pressure of oxygen (P1O2), which is substantial at higher altitude relative to sea level. Consequently, some devices claiming an equivalent HH experience under normobaric conditions would significantly overestimate the HH condition, especially when simulating altitudes above 10,000 ft (3048 m). At best, the claim should be that the devices provide an approximate HH experience since they only duplicate the ambient PO2 at sea level as at altitude. An approach to reduce the overestimation and standardize the operation is to at least provide machines that create the same P1O2 conditions at sea level as at the target altitude, a simple software upgrade.
Johnny Conkin
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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:  82     ISSN:  0095-6562     ISO Abbreviation:  Aviat Space Environ Med     Publication Date:  2011 Dec 
Date Detail:
Created Date:  2011-12-26     Completed Date:  2012-01-17     Revised Date:  2012-09-05    
Medline Journal Info:
Nlm Unique ID:  7501714     Medline TA:  Aviat Space Environ Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1157-8     Citation Subset:  IM; S    
Universities Space Research Association, Houston, TX 77058-2769, USA.
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MeSH Terms
Atmosphere Exposure Chambers*
Atmospheric Pressure
Computer Simulation
Materials Testing
Partial Pressure
Reg. No./Substance:
Comment In:
Aviat Space Environ Med. 2012 Sep;83(9):912-3   [PMID:  22946358 ]

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

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