The control of postoperative pain by EMG biofeedback in patients undergoing hysterectomy

Electromyographic (EMG) measurements from the forehead and rectus abdominis areas were undertaken in a group of patients presenting for elective hysterectomy. The efficacy of EMG auditory feedback as a means of inducing relaxation so as to modify the dose of postoperative analgesia was examined and compared with the dose in subjects having EMG measurements without audiofeedback. Comparison was also made with a group of subjects who did not have EMG measurements. Subjects in those groups who were given relaxation instruction received less postoperative analgesia than subjects not receiving this treatment. A reduction in EMG activity was demonstrated with auditory feedback, but this did not relate directly to reduced analgesic administration after surgery.