Background: Microemboli generated during cardiopulmonary bypass (CPB) are implicated in the cerebral injury seen after coronary artery bypass grafting. Centrifugal pumps generate fewer microemboli than roller pumps. Increased S100beta levels have been reported after coronary artery bypass grafting, with levels greater than 1 ng/mL resulting in poorer neuropsychologic outcome. This study investigated the potential neurologic benefits of centrifugal pumps, by using S100beta as a marker for cerebral injury.
Methods: Thirty-two patients who had coronary artery bypass grafting were randomly assigned to two groups. Serial blood samples (preoperative, end of bypass, 30 minutes, and 2 and 24 hours after cardiopulmonary bypass) were taken and the serum analyzed for S100beta using a new immunoluminometric assay.
Results: Both groups were matched for age, number of grafts, and cardiopulmonary bypass and cross-clamp times. Postoperative serum S100beta levels were significantly higher in both groups than preoperative levels. Peak S100beta levels did not correlate with cardiopulmonary bypass time; however, 24-hour S100beta levels correlated with intubation time r = 0.40, p = 0.04). Th ere was no significant difference in S100beta levels between the groups at any of the time points.
Conclusions: S100beta levels increased after coronary artery bypass grafting. Centrifugal pumps do not significantly decrease S100beta release. Persistently increased S100beta levels are associated with longer intubation times.