Theoretical and experimental intravascular gas embolism absorption
dynamics.
Branger, Annette B., and David M. Eckmann.
1Department of Biomedical Engineering, Northwestern University,
Evanston, IL 60208; 2Department of Anesthesia and The Institute for
Medicine and Engineering, University of Pennsylvania, Philadelphia,
PA 19104
APStracts 6:0263A, 1999.
Multifocal cerebrovascular gas embolism occurs frequently during
cardio-pulmonary bypass and is thought to cause postoperative
neurologic dysfunction in large numbers of patients. We developed a
mathematical model to predict the absorption time of intravascular
gas embolism (IGE), accounting for the bubble geometry observed in
vivo. We modeled bubbles as cylinders with hemispherical end caps and
solved the resulting governing gas transport equations numerically.
We validated the model using data obtained from videomicroscopy
measurements of bubbles in the intact cremaster microcirculation of
anesthetized male Wistar rats. The theoretical model using in vivo
geometry closely predicted actual absorption times for experimental
IGEs and was more accurate than a model based on spherical shape. We
computed absorption times for cerebrovascular gas embolism assuming a
range of bubble geometries, initial volumes, and parameters relevant
to brain blood flow. Results of the simulations demonstrated
absorption time maxima and minima based on initial geometry, with
several configurations taking as much as 50% longer to be absorbed
than would a comparable spherical bubble.
Received 16 February 1999; accepted in final form 8 June 1999.
APS Manuscript Number A117-9.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1999 The American Physiological Society.
Published in APStracts on 22 June 1999