In the present prospective, randomized controlled trial, 110 unpremedicated patients undergoing orthopedic surgery under regional anesthesia were randomly divided into 5 groups, with 22 patients in each. During the operation, group 1 listened to a pre-recorded explanation and music, group 2 listened to a subliminal sound, group 3 received propofol by patient-controlled sedation (PCS), group 4 received
intravenous midazolam, and group 5 was the control group. Patients in the midazolam group were significantly more sedated than the control group at 1 hr. into the operation. The group that listened to an explanation and music were significantly less satisfied than the propofol group at the end of the operation and 30 min. postoperatively. An incremental cost-effectiveness ratio showed that if explanation and music are used instead of propofol it would save 299.53 baht per patient, but the patient satisfaction score will be 17.26 points lower than if the more expensive drug is used.

Keywords: Regional anesthesia, Adjunct technique, Subliminal sound, Music, Patient-controlled sedation