Neurological events in cardiac surgery.

Fifty consecutive coronary artery bypass grafting (Group I) and 50 single valve replacement (Group II) procedures were compared with 50 coronary artery bypass grafting with valve replacement (Group III) procedures and 50 multi-valve procedures (Group IV) to determine the frequency of neurological complications after cardiopulmonary bypass (CPB). The possible risks and aetiological implications were studied. The overall surgical mortality rate was 7.5%, being 0%, 4%, 6% and 20%, respectively for the different groups. The neurological event was not the primary cause of death in any of the patients. After CPB, neurological manifestations occurred in 4% of the patients in Gr. I, in 6% in Gr. II, in 4% in Gr. III, and in 8% in Gr. IV. Three patients had peripheral nerve paresis. The age of the patients and the duration of the CPB operation were not factors in the risk of neurological complications. Previous neurological events seemed to increase the frequency of postoperative neurological disorders, whereas combined procedures were no more dangerous in this respect.