Cerebral complications after cardiac surgery assessed by S-100 and NSE levels in blood

Objective: Assessment of the value of blood analysis of the astroglia protein, S-100, and neuron-specific enolase for the detection of nervous system dysfunction after cardiac surgery. Design: Prospective study. Neurologists blinded from laboratory results. Setting: University hospital. Participants: 38 patients undergoing cardiac surgery. Interventions: 21 patients were operated for coronary artery disease; seven patients with replacement of the aortic valva of whom 2 also had coronary bypass. Four patients had mitral valve replacement of whom 2 also had coronary bypass. One patient had both aortic and mitral valve replacement and coronary bypass. Two patients were operated on because of aortic arch aneurysm. Measurements and Main Results: Neurologic examinations were performed before and after surgery. General behavior of the patients was repeatedly assessed. Flood samples for analysis were collected before operation and on the second day after surgery. In 8/38 patients (21%), a neurologic complication, one of which was lethal, occurred. In 27 patients (71%), the neurologic outcome was uncomplicated, and in 3 (8%), it could not be classified. Elevated S-100 and neuron-specific enolase levels were found in 7/8 patients who endured a neurologic complication and in 4/27 free of complication. (Fisher's exact test p < 0.001). Positive and negative predictive values were 64% and 96%, respectively. S-100 (range 0.5 to 1.3 mu g/L) and neuron-specific enolase levels (range 8.6 to 16.7 mu g/L) were lower for the 7 patients with nonlethal complications than for the patient who died (9.5 mu g/L and 31.3 mu g/L, respectively). Conclusions: S-100 and neuron specific enolase levels after cardiac surgery are associated with neurologic complications. The results have implications on patient related treatment and prognosis as well as for the development of safer perfusion techniques. (C) 1995 by W.B. Saunders Company