Experimental Production of Cerebral Hypothermia by Ventricular Perfusion Techniques

Abstract

C EREBRAL hypothermia has become an important tool. The various methods for obtaining lowered temperatures of the brain, however, have defects tha t in some fashion limit their applicability. The pharmacologic method designed to simulate hibernation is useful only when moderate reductions in temperature are required. 3 Cooling of the total body (ice, refrigerated blankets, etc.) has the disadvantage tha t cardiac arrhythmias occur a t temperatures of about 25~ 1 Since isolated cooling of the brain can circumvent this difficulty, refrigeration of blood circulated locally and oxygenated artificially has been perfected. This has been adapted clinically with good results? I t might be anticipated tha t hemorrhage, secondary to heparinization, might occur. Mas te ry of this pump-oxygenator technique is vital, and of course the equipment and procedures can be cumbersome. Recent work by Negrin, 4 0 m m a y a and Baldwin, 5 and Tokuoka et al. 6 has shown the feasibility of localized cerebral ventricular perfusion using a hypothermic solution. Their work till now has been reported briefly and the physiologic changes have not been well documented. The techniques appeared uncomplicated and the usefulness seemed significant. This report, therefore, is a description in detail of the devices developed in our laboratory, the problems encountered and the results obtained when cerebral ventricular perfusion has been used in experimental animals.