Are serum S100β proteins and neuron-specific enolase predictors of cerebral damage in cardiovascular surgery?

Abstract

Objective: To examine whether serum concentrations of S100β protein and neuron-specific enolase (NSE) are predictors of cerebral damage in cardiovascular surgery. Design: Prospective clinical study. Setting: University hospital. Participants: Eighteen patients with conventional cardiopulmonary bypass (CPB), 7 with selective cerebral perfusion (SCP), and 3 volunteers (blood samples). Interventions: None. Measurements and Main Results: S100β and NSE were measured in the blood obtained at 7 time points during and after operation. The concentrations of these markers in the blood from the surgical field and the cell-saver device, and the influence of graded hemolysis (in vitro) on the concentrations of these proteins were also examined. The mean values of S100β in the CPB group (2.08 ± 2.00 ng/mL) and the SCP group (1.46 ±0.77 ng/mL) were highest after aortic declamping and after termination of SCP, respectively. The mean values of NSE in the CPB group (29.1 ± 14.0 ng/mL) and the SCP group (31.2 ± 13.6 ng/mL) were highest after termination of CPB and at the end of the operation, respectively. Three patients suffered from cerebral complications, but the elevation of these markers during operation was indistinguishable from those in the other patients. Peak concentrations of S100β protein in the CPB group and NSE in the SCP group were correlated with the duration of aortic cross-clamping and CPB, respectively. S100β protein and NSE concentrations in the blood from the surgical field were significantly larger than those in arterial blood, whereas the concentrations in the blood in the cell-saving device were not elevated. The concentration of S100β protein was not influenced by the extent of hemolysis, whereas NSE concentration was markedly elevated by hemolysis. Conclusion: A large part of the increases in S100β protein and NSE during CPB and SCP is not attributed to neuronal damage, but to contamination with the blood from the surgical field. To determine whether these markers are useful to predict neurologic complications, it will be necessary to exclude contamination from the surgical field as observed in the present study. Copyright 2003, Elsevier Science (USA). All rights reserved.