Clinical study of so-called unconscious perception during general anaesthesia

Abstract

Ninety-one patients undergoing biliary tract surgery were randomly assigned to one of three treatment groups in which different sounds were administered, by means of earphones, in a double-blind design. The effects of the administration of positive suggestions, noise or operating theatre sounds on the postoperative course were studied. Results showed that exposure to positive suggestions during general anaesthesia, as compared with noise or operating theatre sounds, protected patients older than 55 yr against prolonged postoperative stay in hospital.