S100 beta after coronary artery surgery: Release pattern, source of contamination, and relation to neuropsychological outcome

Background. ST100 beta has been suggested as a marker of brain damage after cardiac operation. The aim of this study was to characterize the early ST1 00 beta release in detail and relate it to neuropsychological outcome. Methods. Three groups of patients were investigated. All patients underwent coronary artery bypass surgery (CABG) with extracorporeal circulation. In group A, 110 patients had sampling of S100 beta for the first 10 postoperat ive hours and also underwent neuropsychological testing. In group B, 14 pat ients were examined for the effect of autotransfusion on sloop levels. Eigh t patients in group C had their intraoperative bleeding processed with a ce ll-saving device. Results. Group A had a heterogeneous release pattern with several rapid ele vations in ST100 beta concentration. In group B, high concentrations of S10 0 beta were found in the autotransfusion blood (range 0.2 to 210 mu g/L) wi th a concurrent elevation of serum Sloop levels after transfusion of shed b lood. In group C, high levels of S100 beta were found in the blood from the surgical field (12.0 +/- 6.0 mu g/L) and decreased (1.1 +/- 0.64 mu g/L) a fter wash. Group C had significantly lower S100 beta values at the end of c ardiopulmonary bypass compared to group A (0.53 +/- 0.35 mu g/L versus 2.50 +/- 1.5 mu g/L). S100 beta values were corrected for extracerebral contami nation with a kinetic model. With this correction, an association was found between adverse neuropsychological outcome and Sloop release in group A (r = 0.39, p < 0.02). Conclusions. A significant amount of S100 beta is found both in the blood f rom the surgical field and in the shed mediastinal blood postoperatively. I nfusion of this blood will result in infusion of sloop into the blood and i nterfere in the interpretation of early systemic S100 beta values. (C) 1999 by The Society of Thoracic Surgeons.