%A Robert Fitzgerald %A Claus Lamm %A Wolfgang Oczenski %A Thomas Stimpfl %A Walter Vycudilik %A Herbert Bauer %J Anesthesia and Analgesia %T Direct Current Auditory Evoked Potentials During Wakefulness, Anesthesia, and Emergence from Anesthesia %X Direct current auditory evoked potentials (DC-AEPs) are a sensitive indicator of depth of anesthesia in ani-mals. However, they have never been investigated in humans. To assess the potential usefulness of DC-AEPs as an indicator of anesthesia in humans, we performed an explorative study in which DC-AEPs were recorded during propofol and methohexital anesthesia in hu-mans. DC-AEPs were recorded via 22 scalp electrodes in 19 volunteers randomly assigned to receive either propofol or methohexital. DC-AEPs were evoked by binaurally presented 2-s, 60-dB, 800-Hz tones; meas-urements were taken during awake baseline, anesthesia, and emergence. Statistical analysis included analy-sis of variance and discriminant analysis of data acquired during these three conditions. About 500 ms after stimulus presentation, DC-AEPs could be ob-served. These potentials were present only during base-line and emergence?not during anesthesia. Statistically significant differences were found between baseline and anesthesia and between anesthesia and emergence. In conclusion, similar effects, as reported in animal studies of anesthetics on the DC-AEPs, could be observed in anesthetized humans. These results dem-onstrate that DC-AEPs are potentially useful in the assessment of cortical function during anesthesia and might qualify the method for monitoring anesthesia in humans. %K anesthesia, DC-potentials, monitoring of anesthesia, EEG, consciousness %P 154-160 %V 92 %D 2001 %L cogprints1633