Psychological functioning after halothane or enflurane anesthesia.

Halothane and enflurane anesthesia were administered without surgery to young volunteer subjects who were compared with unanesthetized control subjects. All subjects were tested for intellectual function, visual-motor coordination, and personality characteristics, and they were asked to complete a symptom checklist on three occasions: before anesthesia, 2 days after anesthesia, and 2 weeks after anesthesia. Except for slight temporary effects in a few individuals, anesthesia altered neither intellectual or visual-motor measures nor personality characteristics. Although both anesthetics induced a number of symptoms persisting for 2 days after anesthesia, malaise was clearly greater following halothane than enflurane. Halothane was specifically associated with difficulty in remembering things, difficulty in concentrating, faintness or dizziness, and having to do things slowly to do them right. These symptoms were absent at the 2-week test.