Methods: Thirty patients with elective coronary artery bypass grafting were randomized into two groups (Group A pulsatile, and Group B non-pulsatile). In all cases a roller pump with a pulsatile and non-pulsatile mode was used for CPB. Serial blood samples (preoperative, beginning of CPB, before aortic cross clamp release, during skin closure and 6 and 12 hours postoperatively) were collected. The serum was analyzed for S100B using immunoluminometric assay.

Results: Both groups were matched for age, number of grafts, and duration of CPB and aortic cross clamping, the time of ventilation and ICU stay. Postoperative levels of S100B were significantly higher in both groups compared to the preoperative levels (p < 0.001). Although S100B levels were higher at the time of declamping the aorta and during skin closure in the non-pulsatile group (1.7 vs 1 and 2.2 vs 1.74 mg/L; p > 0.05), there was no significant difference in S100B levels between the groups at any time.

Conclusions: Serum levels of S100B increase significantly during CPB. However, pulsatile perfusion does not reduce serum S100B release significantly during CBP compared with non-pulsatile perfusion. These results indicate that pulsatile blood flow does not have a neuroprotective effect.