Comparison of lumbar and thoracic epidural narcotics for postoperative analgesia in patients undergoing abdominal aortic aneurysm repair

Objective: To determine whether there is an advantage of thoracic over lumbar epidural narcotics for postoperative analgesia in patients undergoing abdominal aortic aneurysm repair. Design: A prospective randomized study. Setting: Subjects were inpatients at an academic medical center. Participants: Fifty-two patients scheduled for elective abdominal aortic aneurysm repair. Interventions: Subjects were randomly assigned to receive lumbar or thoracic epidural narcotics. Group 1 ( n = 26) had lumbar, and group 2 ( n = 26) had thoracic epidural catheters placed preoperatively. All patients were monitored with pulmonary artery catheters and arterial catheters, and had general endotracheal anesthesia, in addition to epidural anesthesia with 2% lidocaine. All patients received 5 mg of epidural morphine after intubation. Pain scores were monitored hourly for 36 hours using a visual analog scale, and additional narcotics were given, depending on the level of pain. Complications caused by epidural narcotics were recorded. Results: There was no difference between groups as to the daily dose of narcotics or the time between narcotic doses. Hourly pain scores showed significant differences during hours 6, 7, 8, 20, 34, and 36, with pain scores being lower in group 1. There was no difference in the rate of complications between the groups. Conclusion: There is no advantage of thoracic over lumbar epidural analgesia using morphine in patients undergoing abdominal aortic aneurysm repair.