Journal of Applied Physiology, Vol 38, Issue 4 643-646, Copyright © 1975 by American Physiological Society
Blood flow during 2-Torr exposures at different decompression rates
J. P. Cooke and R. M. Olson
Central and peripheral blood flow of denitrogenated dogs, measured in the
femoral artery and aorta, declined rapidly and ceased within mean times of
28, 35, 70, or 90 s after 1-, 10-, 30-, or 60-s decompressions from 258
Torr to 2 Torr, respectively. Neither arterial nor venous hypoxemia was
seen after 1-s decompressions since the hypoxic blood did not reach the
aorta. In contrast, arterial and venous O2 saturation levels dropped as low
as 12 or 6% following 10- to 60-s decompressions since circulation
continued. A severe and transient decerebratelike rigidity and subsequent
temporary flaccid paralysis of the hind legs was seen during recovery from
decompressions slower than 1 s, whereas only a mild temporary flaccid
paralysis was frequently present after 1-s decompression. The more severe
responses following 10- to 60-s decompressions are associated with the
greater hypoxemia after slow decompressions, indicating tissue hypoxia is
more severe when decompression rate is slow.
