Comparison of the efficacy of epidural morphine given by intermittent injection or continuous infusion for the management of postoperative pain.

BACKGROUND AND OBJECTIVES: To compare the effectiveness and side effects of epidural morphine sulfate (MSO4), delivered by continual infusion or intermittent bolus. METHODS: Thirty patients undergoing upper abdominal surgery were randomized into two equal groups to receive MSO4 through a thoracic epidural catheter by one of two methods. Group 1 patients received an initial bolus of morphine (0.07 mg/kg) at the end of surgery, followed by injections of 2-5 mg morphine into the epidural catheter on demand. Patients in group 2 received an initial bolus of morphine (0.03 mg/kg) during surgical peritoneal closure and were immediately started on an infusion of 0.01% morphine at 5 mL/hour (0.5 mg/hour). The infusion dose was titrated from 0.2 to 1.0 mg/hour, dependent on side effects. Outcome measurements included pulmonary function studies, arterial blood gases, morphine plasma levels, pain relief scores, global evaluations, and side effects. RESULTS: No difference existed between groups in forced vital capacity, forced expiratory volume in 1 second, or in arterial blood gas measurements. Side effects were similar in both groups. Respiratory depression was not seen in either group. Group 2 reported significantly better analgesia than group 1 on postoperative days 1 and 2 (P < .01). Peak plasma morphine levels for group 1 were significantly higher than the steady state plasma morphine levels for group 2 (P < .05). CONCLUSIONS: Continuous epidural infusion provides better analgesia without increased side effects for postoperative pain when compared with an intermittent (or demand) bolus technique.

Early experience with high thoracic epidural anesthesia in outpatient submuscular breast augmentation.

High thoracic epidural anesthesia was administered by anesthetists in 20 patients undergoing submuscular breast augmentation. An average of 12 ml of 2% lidocaine was instilled after sedation with midazolam, 2-6 mg. The augmentation procedure averaged 90 minutes. In 3 patients, the block developed more rapidly on one side than the other, but soon became symmetrical in all; additional subcutaneous infiltration of lidocaine was necessary in 1 patient because of infraclavicular pain; ephedrine, 10 mg was needed in 2 patients to treat hypotension (greater than 20% decrease in blood pressure). Three patients felt infraclavicular pressure; 1 had a brief sensation of breathlessness; 3 had nasal stuffiness from Horner's syndrome associated with the block; none developed headache, back pain, or paresthesias; and 3 had postoperative nausea. The average time from the end of the procedure to patient discharge was 96 minutes. In this limited series, high thoracic epidural anesthesia for submuscular breast augmentation was extremely satisfactory.