EFFECTS OF ETHER ANESTHESIA AND SURFACE-INDUCED HYPOTHERMIA ON REGIONAL BLOOD-FLOW

Regional blood flow and distribution of cardiac output (CO) were evaluated by the radioactive microsphere technique in seven rhesus monkeys prior to anesthesia, following the induction of deep ether anesthesia and throughout the cooling course during surface-induced hypothermia to temperatures of 20° C. As given, deep ether anesthesia alone significantly decreased OC 10 per cent to 15 per cent and output fraction (Qt) was decreased to the carcass, increased to the slanchnic circulation (although not statistically significant), and unchanged to other organs, while total vascular (TVR) and organ resistances were reduced. With the addition of cooling, CO progressively decreased. Individual organ Qt's, however, did not change from anesthetized parallel to the reduction of CO as cooling progressed. TVR and organ vascular resistances increased to levels in excess of 150 per cent of anesthetized precooling values, apparently as the result of viscosity rather than vascular changes. © 1979.