The effect of anemia on intrapulmonary shunt during atelectasis in
rabbits.
Deem, Steven, Michael J. Bishop, Michael K. Alberts.
Department of Anesthesiology, Seattle Veterans Affairs Medical
Center, University of Washington, Seattle, Washington 98195-6540
APStracts 2:0351A, 1995.
To elucidate the effects of anemia on intrapulmonary shunt, we studied
a model of left lung atelectasis in anesthetized rabbits. In nine
rabbits, isovolemic anemia was produced by sequential hemodilution.
Seven control rabbits were followed over time, without hemodilution.
Intrapulmonary shunt was measured using blood gas analysis (Qs/Qt),
and by quantitation of the percentage of blood flow to the collapsed
lung (Qll/Qt) using fluorescent microspheres. In control rabbits,
Qs/Qt and Qll/Qt decreased over time, while PaO2 increased. In
hemodiluted rabbits, there was a trend towards increased Qs/Qt and
Qll/Qt. There were significant differences in the behavior of Qs/Qt,
Qll/Qt, and PaO2 between control and hemodiluted rabbits. Hemodynamic
parameters, including cardiac output and pulmonary artery pressure,
were not different between groups. In a third group of rabbits with
pharmacologically induced acidosis but no hemodilution, Qs/Qt and
Qll/Qt decreased over time, and PaO2 increased. We conclude that
acute isovolemic anemia has a deleterious effect on pulmonary gas
exchange, possibly through attenuation of hypoxic pulmonary
vasoconstriction.
Received 26 September 1994; accepted in final form 1 August 1995.
APS Manuscript Number A996-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 14 August 1995.