Ability of patients to retain and recall new information in the post-anaesthetic recovery period: a prospective clinical study in day surgery.

Abstract

Patients are frequently told new information in the early postoperative period and may retain little of it. Two hundred patients undergoing general anaesthesia for day surgery procedures were randomly allocated into two equal groups, 'Early' and 'Late'. Both groups were asked to undertake a simple memory test either in the early or late postoperative phase of their recovery. A list of five objects was verbally presented and recall of these five objects was tested after 30 min. A control group of 100 patients performed the same test. Patients in the control group received no sedative medications. Statistically significant differences (p < 0.001) in recall ability were demonstrable between each of the three groups. Twenty-three percent of patients in the 'Early' group had total amnesia of any test information given. Only 1% of the 'Late' group were unable to remember any information; a mean interval of 40 min separated the two groups. We recommend that verbal information given postoperatively be delayed until a recovery interval of at least 40 in, and should be supported with written material.