What Patients Hear Under Anesthesia

The banter of the operating room may have to be toned down, if new research on unconscious awareness in patients under total anesthesia is borne out. Surgeons have taken their patients' oblivion as license for talking as though the patient were not there&md;even making remarks that patients would find frightening if they heard. But two research groups report that what anesthetized patients hear can affect them.

"What the patient hears&md;say a remark like, &ls;He's a goner' &md;could conceivably have an adverse effect on his recovery," says Henry Bennett, one of the researchers. In one study, anesthetized patients heard a taped voice tell them during surgery they should signify having heard the message by touching their ears in a postoperative interview. Later, in the interview, the patients tugged at their ears, although none could recall having heard the message, nor were they particularly aware of touching their ears.

Dr. Bennett, a psychologist now at the Univ. of California Medical school at Davis, reports that when patients were given the suggestion during surgery that one hand was becoming warmer and the other cooler, the hands' temperature did so. This suggests, says Bennett, inadvertent negative remarks&md;such as, "Holy Moses, this is a terrible bone graft" &md;could interfere with recovery.

Under anesthesia, "Patients may be more vulnerable to upsetting remarks they might hear," Bennett says. "Their normal coping techniques aren't available, since they are drugged." Other research involving patients undergoing back surgery suggests possible beneficial applications. Because a common postoperative complication of back surgery is difficulty is urinating, most patients require a catheter. During surgery, the researchers suggested to the anesthetized patients that they would be able to relax their pelvic muscles afterward, and so need no catheter. None of the patients who received the suggestion subsequently needed a catheter.