The effect of zero-balanced ultrafiltration during cardiopulmonary bypass on S100b release and cognitive function.

Zero-balanced ultrafiltration (ZBUF) might reduce the systemic inflammatory response (SIRS) during cardio-pulmonary bypass (CPB) by removing inflammatory mediators. The objective of this study was to determine the effect of ZBUF on postoperative serum S100b levels, a marker of neuronal injury. In addition, the possible effects of ZBUF on postoperative neurocognitive function were assessed.Sixty patients undergoing elective coronary bypass grafting were randomly assigned either to a control group or to a protocol group in which ZBUF was performed.Serum S100b levels were measured five minutes after intubation, at the end of bypass and eight and 20 hours after arrival at the intensive care unit (ICU). Cognitive function was assessed with neuropsychological tests on the day before the operation and the sixth day after surgery. The S100b level at 20 hours after arrival at the ICU was 0.27 g/L (SD 0.16) in the control and 0.25 g/L (SD 0.12) in the group with ZBUF. There were no statistical differences at any ti...