The Influence of Duration of Circulatory Arrest at 20°C on Cerebral Changes

Abstract

Sl'~DIA!n' III illfallts IIlld pz/;lets sulijected to periods of circulatory arrest at ;!()GC there u.'as close corrclatiol1 bet1£'eell duratioll of arrest alld de/a)' in return of c/ectroel1ceplza/ographic actit'ity. Post mortem studies demonstrated histological lTidelIce of brain damage in patients after circulatory arrest at 20°C. Similar histolor;ical changes lt'ere demonstrated in piglets, including some wlzo had complete I,'.E.(;. and clillical rcc07'ery fro/ll circl/latory arrest. In a pre\'ious stud~' of the effects of circulator~' arrest at :WcC in the infant pig (Fisk et al. ] 974), we found lesions in the cerebral cortex of pigs subjected to circulatory arrest for a period of one hour at 20°C and then allowed to survivc for 1 0 da~'s before being killed. These lesions were not found in pigs subjected to continuous perfusion at 20°C or at ;)72C. \\'e suggested tha~ the delay in return of electrocncephalogram (E.E.G.) activity after such circulatory arrest may be a useful index of the degree of ischaemic cerebral insult. BreclmtT et al. (HI;)~I) showed an eXjlonential relationship between the period of circulatory arrest at :~OcC in patients undergoing open-heart surgny and the time taken for return of continuous E.E.G. activity. They suggested that this provided a guide to the severity of the ischaemic insult of the brain. In this pillwr we report on E.E.G. activity and postmortem histological examination of the brain in infants SUbjected to circulatory arrest for open-heart surgery, and on the results of a study of infant pigs subjectcd to various periods of circulatory arrest at 20°C. \\'c have attempted to "correlate the period of arrE'st and the associated delay in return of E.E.C. activity with the presence of detectable histological changes in the cerebral cortex in surviving piglets.

An Experience on Normothermic Beating Heart Pulmonary Thromboendarterectomy

“…This suggests that, some metabolic activity still go on irrespective of the temperature of cell, so the time limit of circulatory arrest should be accurate. Usually at a temperature of 18˚C, a safe circulatory arrest time period of 30 minutes is possible without any structural or functional derangement of brain functions [13] [14]. [24].…”

Cerebral blood flow and metabolism during infant cardiac surgery

“…Although all organ systems are at risk for the development of ischaemic and reperfusion injury as manifested by lactate and pyruvate production during DHCPB with DHCA, the brain appears to be the most sensitive and the least tolerant to these effects. DHCA has been associated with a number of poorly understood effects on the brain in the immediate post-CPB period including: 1) reduced cerebral blood flow; 2) disordered brain metabolic activity and 3) delayed functional recovery (Greeley et al 1989aFisk et al 1976). Experimentally, Watanabe ef al.…”

“…Other experimental investigations using CK-BB (Rossi et al 1987) cerebral blood flow (CBF) (Miyamoto et al 1986), cerebral metabolic rate for oxygen (CMR02) (Perna ef al. 1973), electroencephalography (Fisk et a!. 1976) and brain histology (Treasure ef al.…”

“…At this point basal metabolism ceases, cellular integrity can no longer be maintained and cerebral injury may ensue. Reports of the association of increasing duration of DHCA and worsening neurohistopathological or metabolic recovery suggest that DHCA participates directly as a cause of injury (Fisk et al 1976;Mault et al 1993.3). The lack of substrate delivery (oxygen, glucose) adversely affects the cellular level of high energy compounds.…”

Psychomotor Development of Infants and Children after Profound Hypothermia during Surgery for Congenital Heart Disease

“…Post-operative complications, including immediate neurological impairment, appear to be no more frequent than for patients of the same age after major cardiovascular surgery with cardiopulmonary bypass (Steward et al 1974). However, there is some concern that there may be long-term neurological sequelae after surgery under profound hypothermia; such have been reported in histopathological studies (Egerton et al 1963, Brunberg et al 1974, Fisk et a/. 1976, although a more optimistic clinical outcome has been indicated (Stevenson et al 1974, Messmer et al 1976, Subramanian et al 1976.…”