Abstract
Electroencephalography can detect both cerebral ischemia/ hypoxia and seizures and can measure hypnotic effects. The author reported two patients with left main coronary artery disease and myocardial infarction scheduled for urgent coronary artery bypass grafting surgery; they developed abrupt decreases in response entropy (RE) and state entropy (SE) values to isoelectric silence during target-controlled propofol-sufentanil anesthesia. After that, low RE and SE values persisted throughout the intraoperative period. Both patients showed delayed awakening after surgery and brain CT revealed nonhemorrhagic tempro-parietal cerebral infarctions. Intraoperative entropy-based monitoring could predict poor neurological outcome after cardiac surgery during targetcontrolled propofol and sufentanil anesthesia.