SHORT-TERM AND LONG-TERM NEUROPSYCHOLOGICAL CONSEQUENCES OF CARDIAC-SURGERY WITH EXTRACORPOREAL-CIRCULATION

Objective: Cognitive dysfunction after extracorporeal circulation is a major continuing problem in modern cardiac surgery. We designed this prospective study to update the incidence of postoperative neuropsycho logical changes after routine cardiopulmonary bypass (CPB) and to iden tify perioperative variables associated with these complications. Meth ods: We assessed the patients with a comprehensive neuropsychological test battery 1 day before, 7 days after (n = 109) and 6 months after ( n = 91) cardiopulmonary bypass. We used patients undergoing major vasc ular or thoracic surgery as a surgical control group (n = 20). Results : Repeated measures multivariate analysis of variance (using surgical group as a between-subjects factor) on the group data revealed signifi cant changes early after surgery compared with the preoperative perfor mance (P = 0.001). The early changes are characterized by a significan t decrease of visual attention and verbal memory performance (univaria te F-tests, always P < 0.05). Cardiac patients showing cognitive impai rment after cardiac surgery had lower preoperative ejection fractions (P = 0.014) and a more complicated medical history (P = 0.046). At 6-m onth follow-up, the patients performed significantly better than befor e surgery (P < 0.001). CPB patients showing persistent cognitive impai rment at follow-up were significantly older at the time of surgery (P = 0.005). Individual comparisons revealed that 45% of the patients und ergoing CPB showed evidence of cognitive impairment soon after surgery . In 12% of the patients, the cognitive sequelae persisted at follow-u p. Both group data and individual incidence rates revealed neither sig nificant pre-post differences between the surgical groups nor a time-b y-group interaction effect. Variables directly associated with CPB wer e not significantly associated with the occurrence of cognitive impair ment after surgery. Conclusions: We conclude that an important proport ion of the cognitive impairment after cardiac surgery is likely to be due to nonspecific effects of surgery. (C) 1997 Elsevier Science B.V.