Postoperative anterograde amnesia.

The problems of defining and estimating preand postoperative amnesia are discussed. The extent of postoperative (anterograde) amnesia in patients receiving pre-operative medication (consisting of atropine, pethidine and pentobarbitone) followed by general anaesthesia (consisting of thiopentone, halothane and nitrous oxide) was ascertained. Two control groups were employed; one received spinal anaesthesia following preoperative medication, and the other received no medication and did not undergo surgery. Various age groups were compared and various memory tests were employed. Results indicate that postoperative amnesia is primarily related to the general anaesthetic and not to the pre-operative medication.