Objectives: Cardiac surgery involving cardiopulmonary bypass is associated with neurologic deterioration. Several interventions, including anesthetic techniques, have been designed to limit ischemic brain damage and have been evaluated in animals. Markers of neurologic injury may facilitate the assessment of these interventions in humans.Design: A blinded randomized prospective study comparing 2 anesthetic techniques (one sufentanilbased, the other ketamine and midazolam-based) in patients undergoing cardiac surgery. Quantitative electroencephalography was used to detect postoperative neurologic injury. Setting: Major teaching hospital.Participants: Forty-two patients aged 18 to 70 years undergoing cardiac surgery.Interventions: Patients were anesthetized with either a sufentanil-based or a ketamine and midazolambased technique for cardiac surgery with cardiopulmonary bypass. Quantitative electroencephalography was performed preoperatively as well as 5 to 6 days postoperatively. Measurements and Main Results:Quantitative electroencephalography outcome did not differ (p > 0.05) between the 2 groups. It showed significant deterioration between preoperative and postoperative assessments with a decrease in faster and an increase in slower frequencies. In addition, the alpha attenuation index decreased. This may reflect a decrease in alertness. Both the intergroup comparisons and the assessment of individual changes failed to reveal significant differences between the anesthetic techniques. The adjuvant use of isoflurane correlated with less deterioration of quantitative electroencephalographic variables. Conclusions:The use of either sufentanil-based or ketamine and midazolam-based anesthetic techniques for cardiac surgery with cardiopulmonary bypass had no effects on a marker of postoperative neurologic injury (ie, quantitative electroencephalography).THE MANIFESTATIONS of cerebral injury after cardiac surgery, to some extent ascribable to the effects of cardiopulmonary bypass (CPB), include postoperative delirium, stroke, and cognitive changes.