[Electroencephalographic characteristics during maintenance and emergence from propofol-ketamine-fentanyl anesthesia]

Spectral edge frequency 90 (SEF 90) and relative power in four frequency bands (beta, alpha, theta, delta) of the processed electroencephalogram were recorded in 20 patients undergoing elective gynecological surgery under total intravenous anesthesia (propofol-ketamine-fentanyl) (group PKF, n = 10) or nitrous oxide-oxygen-isoflurane (group GOI, n = 10) anesthesia. During anesthesia, mean SEF 90 and relative beta power increased more significantly in group PKF than in group GOI. At emergence from anesthesia, SEF 90 was 21.8 Hz in group PKF and 20.5 Hz in group GOI. These results suggest that it is difficult to evaluate the depth of anesthesia using pEEG under PKF anesthesia.