Effect of isovolemic hemodilution on cerebral blood flow following experimental head injury.

Abstract

T HE pathophysiology of head injury results from a complex set of interrelated and interdependent factors such as concussion, changes in intracranial pressure and cerebral blood flow, cerebral edema, and cerebrospinal production and absorption. This report is primarily concerned with alterations in cerebral blood flow during acute compression of the brain and in the hours thereafter. While other studies have been carried out on blood flow during various types of head injury and increased intracranial pressure, few have investigated the beneficial effects of increasing blood flow during poor flow conditions. This investigation utilizes our model of extradural compression previously described. 1~ The model furnishes a relatively controlled means of altering brain compression, brain distortion, and intracranial pressure. It also lends itself to greater reliability in studies of mortality and morbidity in a series of animals. This study was carried out in three parts: 1. Changes in cerebral blood flow and arteriovenous oxygen difference induced by extradural compression. 2. Alterations in cerebral blood flow with isovolemie hemodilution. 3. Effects of hemodilution and hemodilution plus hyperbaric oxygenation on mortality and morbidity following cerebral injury.