Effects of Epidural Naloxone on Intestinal Hypomotility Caused by Epidural Morphine after Gastrectomy

Lee, Jai Min; Choi, Jong Ho

Abstract

BACKGROUND: Epidural morphine is usually associated with decreased bowel motility and increased transit time. Low doses of intravenous naloxone have been known to reduce morphine-induced side effects including intestinal hypomotility without reversing analgesia, but the effect of epidural naloxone has not been defined in any human study. Therefore, we evaluated bowel motility and analgesia when naloxone was administered via the epidural route.
METHODS
Forty patients having epiduro-general analgesia for subtotal gastrectomy were randomly assigned to one of two study groups. As a means of postoperative pain control, all received 1.5 mg of epidural morphine bolusly 1 hour before the end of surgery, and a continuous epidural infusion was started using a two-day infusor containing 2.5 mg of morphine in 0.125% bupivacaine 100 ml with either no naloxone (control group, n=20) or 5 microgram/kg/day of naloxone (experimental group, n=20). We measured the time to the first postoperative passage of flatus and feces to evaluate the restoration of bowel function, and visual analog scales (VAS) for pain, during rest and movement. Scores were taken at 2 and 4 hours after the operation, 7 AM, 1 PM, and 7 PM of the 1st postoperative day and 7 AM and 1 PM of the 2nd postoperative day.
RESULTS
The experimental group revealed less time to the first postoperative passage of flatus and feces. No significant difference was found in resting and movement VAS between two groups.
CONCLUSION
This study suggests that epidural naloxone reduces epidural morphine-induced intestinal hypomotility without reversing analgesic effects.