Arousal reactions during anesthesia in man.

Power-spectrum analysis of the electroencephalogram and inhaled-exhaled concentrations of halothane (when used), nitrous oxide, and carbon dioxide of 36 patients during surgical operations under general anesthesia were monitored. Electroencephalographic arousal reactions were detected in 24 patients and these were accompanied by irregular respirations in nine patients. Cardiac arrhythmias occurred following an arousal reaction in eight patients. The authors conclude that this electroencephalographic arousal phenomenon occurs frequently and deserves further investigation to define its clinical implications and how it might be avoided.