Superoxide dismutase and hemodynamic changes following aortic crossclamp release.
Release of an aortic crossclamp usually results in hypotension which is mainly due to hypovolemia from sequestration of fluid in the tissues and the release of vasoactive substances (ie, bradykinin, free radicals) that increase capillary permeability. The purpose of this study was to evaluate superoxide dismutase (SOD), a free-radical scavenger, as a pharmacologic technique to prevent hemodynamic changes following aortic crossclamping and release. Fourteen mongrel dogs were studied and divided into two groups. The aorta was clamped for 60 minutes. Group A received NaHCO3, 3.5 mEq/kg, and SOD, 15,000 U/kg; while group B received only NaHCO3, 3.5 mEq/kg, prior to aortic crossclamp release. There was a statistically significant difference in cardiac output, systolic blood pressure, systemic and pulmonary vascular resistances, and arterial oxygen tension between the two groups following aortic crossclamp release. Cardiac output increased from 2.2 +/- .05 to 2.5 +/- .03 L/min (P < .05) after declamping, and returned toward preclamping baseline values after five minutes in group A. In group B, cardiac output decreased from 2.3 +/- .05 to 2.1 +/- .01 (P < .005) after declamping and remained unchanged five minutes later. No statistically significant changes in PaO2 occurred in group A, while there was a significant decrease in PaO2 in group B after crossclamp release. In group B, PaO2 decreased from 95 +/- 7 to 70 +/- 1 mmHg (P < .005) after crossclamp release. Bradykinin levels were almost identical in both groups studied. It is concluded that SOD significantly decreases the cardiovascular changes following aortic crossclamp release.
Casthely
P A
PA
Department of Anesthesiology, State University of New York Health Science Center, Brooklyn, NY, USA.
Dluzneski
J
J
Jones
R
R
Goodman
K
K
Redko
V
V
Cottrell
J E
JE
Yoganathan
T
T
D000818:Animals; D001011:Aorta / Q000601:surgery*; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004285:Dogs; D006339:Heart Rate / Q000187:drug effects; D013482:Superoxide Dismutase / Q000494:pharmacology*; D014655:Vascular Resistance / Q000187:drug effects
D013482:Superoxide Dismutase