Cerebral blood flow and cerebral metabolism in children following cardiac surgery with deep hypothermia and circulatory arrest. Clinical course and follow-up of psychomotor development.

Between November 1975 and June 1977, 49 children underwent repair of complicated cardiac defects with the aid of deep hypothermia. Circulatory arrest was used in 28 cases. Nine children died (18%) due to early postoperative heart failure. A decisive cause of death in terms of important cardiovascular defects, which were either unknown or not correctable at the time of repair, was found in 6 patients. Children with complicated forms of congenital heart disease requiring an extensive repair were overrepresented among those who died. Hence, there was an excess in the duration of bypass among nonsurvivors (p less than 0.01) whereas the patient's age at operation, the use of circulatory arrest and the duration of aortic occlusion had no bearing on operative mortality. Cerebral blood flow (CBF) and cerebral metabolism were studied in 9 survivors. A negative correlation (r = -0.67) was found between the duration of circulatory arrest and CBF measured directly after surgery. CBF was reduced to values below 0.2 ml . g-1 . min-1 in 3 children with long periods of circulatory arrest. The cerebral uptake of oxygen and glucose was normal both before and after surgery. Two separate interviews with the parents were performed, the first one 3-22 months and the second one about 3 years after surgery. No serious neurological symptoms or psychomotor disturbances were reported. However, in 3 children operated with circulatory arrest, difficulties in performing more delicate motor activities were noted by the parents. The findings indicate that circulatory arrest should be used with caution and total arrest periods exceeding 60 min avoided.