Propofol offers no advantage over isoflurane anesthesia for cerebral protection during cardiopulmonary bypass: a preliminary study of S-100beta protein levels.

Purpose: Despite advances in anesthesia, cardiopulmonary bypass (CPB) and surgical techniques, cerebral injury remains a major source of morbidity after cardiac surgery. We compared the effects of two different anesthetic techniques, isoflurane vs propofol on neurological outcome by serum S-100beta protein and neuropsychological tests after coronary artery bypass grafting (CABG).
Methods: Twenty patients undergoing CABG, randomly allocated into two groups, were enrolled in this prospective, controlled, preliminary study. Isoflurane was used in group I and propofol in group P. Neurological examination and a neuropsychologic test battery consisting of the mini mental state examination (MMSET) and the visual aural digit span test (VADST) were obtained preoperatively and on the third and sixth postoperative days. Blood samples for analysis of S-100beta protein were collected before anesthesia (T1), after heparinization (T2), 15 min into CPB (T3), after CPB (T4) and at the 24(th) hr postoperatively (T5).
Results: Postoperative neurological examinations of the patients were normal. VADST performance declined significantly on the third day (P < 0.05) in both groups, and there were no significant differences on VADST and MMSET scores between the two groups. In group P, S-100beta protein levels increased significantly at T3 and T4 compared to preoperative and isoflurane levels (P < 0.05).
Conclusions: Despite reports about the neuroprotective effects of propofol, S-100beta protein levels were significantly elevated in group P. Although there was no deterioration in neuropsychological outcome, propofol appeared to offer no advantage over isoflurane for cerebral protection during CPB in this preliminary study of 20 patients.