Anesthetic Technic Using Profound Hypothermia for Correction of Congenital Heart Defects in Infants and Small Children

Cardiopulmonary Bypass, Hypothermic Circulatory Arrest and Barbiturate Cerebral Protection for the Treatment of Giant Vertebrobasilar Aneurysms in Children

“…Experimental evidence suggests that hypothermia slows the depletion of high-energy phos phate stores, confers a protective effect on the brain after adenosine triphosphate exhaustion [33], reduces intracra nial pressure and facilitates recovery of electrophysiological function after cerebral ischemia [34], However, hypo thermia increases blood viscosity [35] resulting in the need for hemodilution therapy [36] to reduce the negative effects of hyperviscosity upon ischemic cerebral tissue. Hypothermia also produces a leftward shift of the oxyhe moglobin disassociation curve and concomitant reduced oxygen availability [37,38]. These negative aspects must be carefully weighed against the positive benefits on a case-by-case basis.…”

“…A combination of hypothermia at 18-20°C with cir culatory arrest times of 60-90 min provides good results for pediatric cardiovascular procedures [37]. In addition, the safety of circulatory arrest with hypothermia may be enhanced, in terms of cerebral protective effects, by the concomitant use of barbiturates [14,39], Barbiturates reduce metabolic requirements of neural tissue, and their judicious use in conjunction with hypothermia may ex tend the tolerance of the brain for the substrate reduction that occurs during ischemia [40],…”