A clinical neuropsychological study of the postoperative course after three types of anaesthesia

In a double-blind study, 57 patients were anaesthetized with either Althesin, thiopentone, or fentanyl combined with diazepam for cystoscopies. One and a half and four hours after the administration of anaesthesia, the patients were investigated with an objective neuropsychological method, continuous Reaction Time, and with a subjective rating scale. Beecher's Mood Scale. One week later the patients answered a questionnaire about side-effects experienced during the days following anaesthesia. At the 1 1/2 h investigation, the patients were cerebrally affected, both subjectively and objectively. The CNS-dysfunction was different for the three anaesthetics. After administration of thiopentone, the patients experienced the highest degree of subjective effects but had the smallest reaction time prolongation. Fentanyl-diazepam gave the least subjective effects, but the highest degree of cerebral affection in the reaction time measurements. The effects of Althesin were intermediate. Four hours after anaesthesia, the reaction time prolongations had disappeared, except for Althesin, and only patients who had thiopentone registered subjective effects. The number of side-effects was greatest and most prolonged following thiopentone. About 25% of the patients reported that side-effects had persisted more than 1 day after anaesthesia.