['In a variety of experimental models, propofol has been shown to protect the brain. It was hypothesized that a clinically achievable high dose of propofol would induce cerebral protective effects in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). The authors investigated the effects of different target plasma concentrations of propofol on cerebral injury by measuring serum S-100β protein and neuron-specific enolase (NSE) levels in patients undergoing single-valve replacement with CPB.', 'A prospective, randomized study.', 'A university hospital.', 'Forty-two patients undergoing single-valve replacement with CPB.', 'Patients were randomly divided into 3 groups (n = 14 each). Each group received a target-controlled infusion of propofol with plasma concentrations of 1.8 μg/mL (low dose, Group-L), 2.4 μg/mL (medium dose, Group-M), or 3.2 μg/mL (high dose, Group-H). The propofol target concentrations were unchanged throughout the surgery.', 'In all 3 groups of patients, at all time points after CPB, the plasma S-100β protein and NSE levels, which served as biochemical markers of brain damage, were significantly higher than the preoperative levels (p<0.05). Group-H showed significant decreases in S-100β protein and NSE compared with Group-L (p< 0.05).'] Does high-dose propofol reduce S-100β protein and neuron-specific enolase levels in patients undergoing cardiac surgery?