Conscious sedation with intravenous drugs: a study of amnesia.

A comparison of amnesia that is produced by two intravenous sedation techniques commonly used to reduce anxiety in ambulatory oral surgery patients showed that both techniques induce high levels of safe, predictable amnesia. More than 200 patients undergoing surgical extraction of third molars were asked to verbally identify visual and cutaneous-tactile stimuli intraoperatively. The patients responded via written questionnaires at the postoperative interview sessions. No retrograde amnesia was observed. Complete amnesia was attained for the local anesthetic injections. Amnesia for visual stimuli was significantly lower than for cutaneous-tactile stimuli. No significant differences in amnesia were observed between the two drug combinations studied.