Document Detail


The effect of body position on inspiratory airflow in divers.
MedLine Citation:
PMID:  18251439     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The purpose of this study was to examine the possibility that body position influences inspiratory airflow of submerged subjects. Our previous studies have suggested that for a given (negative) inspired gas pressure, exercising divers experience more dyspnea in the prone than in the upright position. METHODS: Six subjects performed maximal inspiratory efforts recorded as esophageal pressure (balloon catheter); simultaneously inspiratory flow and lung volumes were recorded. To standardize static lung load, the subjects' chest pressure centroids (representing the average water pressure on the chest) were held at a constant depth (0.33m) throughout the experiments. RESULTS: Recordings of peak inspiratory flow (PIF) showed a decrease of 25.56 +/- 4.14% (mean +/- SD, P = 0.01) from the submerged upright position mean flow of 6.19 +/- 1.48 (l/s) to the submerged prone mean flow of 4.37 +/- 0.69 (l/s). Nadiral esophageal pressure exhibited no significant differences: 5.40 +/- 4.32% (mean +/- SD, P = 0.512), from the upright mean pressure of (-) 51.70 +/- 24.09 (cm H2O) to the prone mean pressure of (-) 48.53 +/- 25.86 (cm H2O). CONCLUSIONS: The significant decrease in PIF when changing from the upright to the prone position, suggests a difference in the patency of the extra-thoracic airways. The higher water pressure exerted on the neck in the prone position may explain this difference. The similarity of pleural pressures in the two positions indicates that the differences in PIF were not due to differences in inspiratory effort.
Authors:
M L Krauza; C E G Lundgren
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Publication Detail:
Type:  Journal Article; Randomized Controlled Trial    
Journal Detail:
Title:  Undersea & hyperbaric medicine : journal of the Undersea and Hyperbaric Medical Society, Inc     Volume:  34     ISSN:  1066-2936     ISO Abbreviation:  Undersea Hyperb Med     Publication Date:    2007 Nov-Dec
Date Detail:
Created Date:  2008-02-06     Completed Date:  2008-02-11     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9312954     Medline TA:  Undersea Hyperb Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  425-30     Citation Subset:  IM; S    
Affiliation:
Center for Research and Education in Special Environments (CRESE) and Department of Physiology University at Buffalo, State University of New York, Buffalo, NY 14214, USA.
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MeSH Terms
Descriptor/Qualifier:
Adult
Cross-Over Studies
Diving / physiology*
Female
Humans
Inhalation / physiology*
Male
Posture / physiology*
Pressure
Prone Position / physiology

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


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