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Pulmonary tissue volume, cardiac output, and diffusing capacity in sustained microgravityIn microgravity (microG) humans have marked changes in body fluids, with a combination of an overall fluid loss and a redistribution of fluids in the cranial direction. We investigated whether interstitial pulmonary edema develops as a result of a headward fluid shift or whether pulmonary tissue fluid volume is reduced as a result of the overall loss of body fluid. We measured pulmonary tissue volume (Vti), capillary blood flow, and diffusing capacity in four subjects before, during, and after 10 days of exposure to microG during spaceflight. Measurements were made by rebreathing a gas mixture containing small amounts of acetylene, carbon monoxide, and argon. Measurements made early in flight in two subjects showed no change in Vti despite large increases in stroke volume (40%) and diffusing capacity (13%) consistent with increased pulmonary capillary blood volume. Late in-flight measurements in four subjects showed a 25% reduction in Vti compared with preflight controls (P < 0.001). There was a concomittant reduction in stroke volume, to the extent that it was no longer significantly different from preflight control. Diffusing capacity remained elevated (11%; P < 0.05) late in flight. These findings suggest that, despite increased pulmonary perfusion and pulmonary capillary blood volume, interstitial pulmonary edema does not result from exposure to microG.
Document ID
20040172910
Document Type
Reprint (Version printed in journal)
Authors
Verbanck, S. (Vrije Universiteit Brussel 1090 Brussels, Belgium)
Larsson, H.
Linnarsson, D.
Prisk, G. K.
West, J. B.
Paiva, M.
Date Acquired
August 22, 2013
Publication Date
September 1, 1997
Publication Information
Publication: Journal of applied physiology (Bethesda, Md. : 1985)
Volume: 83
Issue: 3
ISSN: 8750-7587
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
Clinical Trial
Non-NASA Center
short duration
STS-40 Shuttle Project
STS-55 Shuttle Project
NASA Discipline Cardiopulmonary
Flight Experiment
manned