Document Detail

Low level CO2 effects on pulmonary function in humans.
MedLine Citation:
PMID:  9561286     Owner:  NLM     Status:  MEDLINE    
The purpose of the study was to determine whether chamber exposure to low levels of CO2 results in functional alterations in gas mixing and closing volume in humans. Four healthy volunteer subjects were exposed to 0.7% CO2 and to 1.2% CO2. Spirometry, lung volumes, single breath nitrogen washout, diffusing capacity for carbon monoxide (DLCO) by two methods, and cardiac output were measured in triplicate. Values were obtained over two non-consecutive days during the training period (control) and on days 2 or 3, 4, 6, 10, 13, and 23 of exposure to each CO2 level. Measurements were made during the same time of day. There was one day of testing after exposure, while still in the chamber but off carbon dioxide. The order of testing, up until measurements of DLCO and cardiac output, were randomized to avoid presentation effects. The consistent findings were a reduction in diffusing capacity for carbon monoxide and a fall in cardiac output, occurring to a similar degree with both exposures. For the group as a whole, there was no indication of major effects on spirometry, lung volumes, gas mixing or dead space. We conclude that small changes may occur in the function of distal gas exchanging units; however, these effects were not associated with any adverse health effects. The likelihood of pathophysiologic changes in lung function or structure with 0.7 or 1.2% CO2 exposure for this period of time, is therefore, low.
J Sexton; K Mueller; A Elliott; D Gerzer; K P Strohl
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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:  69     ISSN:  0095-6562     ISO Abbreviation:  Aviat Space Environ Med     Publication Date:  1998 Apr 
Date Detail:
Created Date:  1998-06-04     Completed Date:  1998-06-04     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7501714     Medline TA:  Aviat Space Environ Med     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  387-90     Citation Subset:  IM; S    
Case Western Reserve University, Cleveland, OH, USA.
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MeSH Terms
Breath Tests
Carbon Dioxide / poisoning*
Cardiac Output
Chronic Disease
Ecological Systems, Closed
Lung Volume Measurements*
Poisoning / physiopathology
Pulmonary Gas Exchange*
Random Allocation
Space Flight
Time Factors
Reg. No./Substance:
124-38-9/Carbon Dioxide
J B West / U CA, San Diego

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

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