Event-related potential measures of information processing during general anesthesia

摘要: To investigate the incidence and manner of auditory information processing during a state presumed unconsciousness event-related brain potentials (ERPs) were studied in 41 patients undergoing cardiac surgery with propofol/alfentanil anesthesia. The ERPs recorded oddball tasks administered before within several periods operation. Mean nasopharyngeal temperature anesthetic concentrations determined for each intraoperative ERP recording epoch. During anesthesia waves could still be observed up to 500 ms after stimulus onset indicating that was not suppressed completely by agents. Relative preoperative recordings, P1-N1-P2 complex delayed more positive going Comparable changes morphology have been Stage II-IV sleep, suggesting parallels mechanisms underlying early both states reduced arousal level, possibly related selective reduction non-specific activity. N1 P2 peak amplitudes found larger deviant tones compared standard tones. These amplitude differences most likely reflect automatic detection deviance, although it cannot excluded entirely they due refractoriness. Anesthetic minor significance control. It is suggested serve as reference measures, providing earliest evidence processing. This characteristic important validation signals techniques are proposed improve conventional monitoring respect detecting unintended awareness.