A Prospective Randomized Double-Blind Study to Determine the Effect of Thoracic Epidural Neostigmine on Postoperative Ileus After Abdominal Aortic Surgery

Abstract

Postoperative ileus is a major gastrointestinal complication of abdominal aortic surgery leading to increased rates of morbidity and mortality, longer lengths of hospital stay, and higher costs. In this study, we evaluated the effect of epidurally administered neostigmine on postoperative ileus after abdominal aortic surgery. We enrolled 45 patients who were scheduled for elective abdominal aortic surgery at our institution. All patients received identical general and epidural anesthesia. Before the induction of general anesthesia, an epidural catheter was placed at the T7-T8 intervertebral space, and 20 mL bupivacaine (0.5%) was injected over 15 min. Patients were randomized into two groups. Patients received a 5 mL bolus of neostigmine (1 microg/kg) diluted with normal saline (Group 1) or a 5 mL bolus of normal saline (Group 2) via an epidural catheter at the end of surgery and 8 h postoperatively. Times of bowel sounds were recorded postoperatively in the intensive care unit. Times of daily passage of flatus and defecation also were recorded. Times to the first bowel sounds and the first flatus were significantly shorter in Group 1 than they were in Group 2 (11.6 +/- 11.2 h vs 22.6 +/- 12.8 h and 21.8 +/- 15.6 h vs 36.6 +/- 19.1 h, respectively, P < 0.05). The times to first defecation were similar in both groups (P > 0.05). Nausea was more frequent in patients in Group 2 than in Group 1 (P < 0.05). The incidence of postoperative complications was similar between the groups (P > 0.05). Thoracic epidural neostigmine enables faster restoration of bowel sounds and shortens duration of postoperative ileus after abdominal aortic surgery.