CEREBRAL BLOOD FLOW AND EXCHANGE OF OXYGEN, GLUCOSE KETONE BODIES, LACTATE, PYRUVATE AND AMINO ACIDS IN ANESTHETIZED CHILDREN

Abstract

Cerebral blood flow (CBF) and cerebral AV [arteriovenous] differences of O2, glucose, 3-hydroxybutyrate, acetoacetate, lactate, pyruvate and amino acids were measured in anesthetized children before elective surgery to study possible age-dependent variations. CBF was measured in 70 children, aged 11 days to 15 yr. Cerebral AV differences were studied in approximately 50% of the subjects. Mean values were: CBF 0.65 ml .times. g-1 .times. min-1, cerebral exchange in nmol .times. g-1 .times. min-1: O2 1348, glucose 248, acetoacetate 12,3-hydroxybutyrate 34 (uptake), lactate-48, pyruvate-8 (release). No net exchange of amino acids was found except for histidine (uptake). Neither CBF nor the cerebral exchange of O2 and circulating substrates showed any correlation to age within the group. Compared with adults anesthetized by the same technique (barbiturate induction, N2O/O2 relaxant) the children had a slightly higher mean CBF, while the cerebral uptake of O2 and glucose were equal to values in adults. The cerebral uptake of ketone bodies was higher in children than reported values in adults investigated in the awake state after comparable periods of fasting.