Changes in the tissue blood flow in the rabbit brain after burn, acute radiation, and combined injuries

Abstract

The tissue blood flow of the brain was determined in experiments on rabbits with the aid of xenon-133 after severe burns affecting 20% of the body surface, whole-body x-ray irradiation in a dose of 900 rad, and combined exposure to both factors. The cerebral blood flow was found to be reduced by a lesser degree in burns than the minute volume of the heart (on the average by 20–30% and 50%, respectively). In combined trauma the decrease in the cerebral blood flow was the same as with isolated burns or radiation injury. The authors suggest that a greater decrease in the cerebral blood flow is incompatible with life. The results are evidence of the existence of compensatory mechanisms aimed at maintaining the cerebral blood flow despite a fall in the minute volume of the heart.