Preincisional and postoperative epidural morphine, ropivacaine, ketamine, and naloxone treatment for postoperative pain management in upper abdominal surgery

OBJECTIVE(S): Previous studies have shown that preincisional epidural morphine, bupivacaine, and ketamine combined with epidural anesthesia (EA) and general anesthesia (GA) provided pre-emptive analgesia for upper abdominal surgery. Recent studies reported that ultralow-dose naloxone enhanced the antinociceptive effect of morphine in rats. This study investigated the benefits of preincisional and postoperative epidural morphine + ropivacaine + ketamine + naloxone (M + R + K + N) treatment for achieving postoperative pain relief in upper abdominal surgery. METHODS: Eighty American Society of Anesthesiology I-II patients scheduled for major upper abdominal surgery were allocated to four groups in a randomized, single-blinded study. All patients received combined GA and EA with a continuous epidural infusion of 2% lidocaine (6-8 mL/h) 30 minutes after pain regimen. After GA induction, in Group I, an epidural pain control regimen (total 10 mL) was administered using 1% lidocaine (8 mL) + morphine (2 mg) + ropivacaine (20 mg; M + R); in Group II, 1% lidocaine 8 (mL) + morphine (2 mg) + ropivacaine (20 mg) + ketamine (20 mg; M + R + K); in Group III, 1% lidocaine (8 mL) + morphine (2 mg) + ropivacaine (20 mg) + naloxone (2 μg; M + R + N); and in Group IV, 1% lidocaine (8 mL) + morphine (2 mg) + ropivacaine (20 mg) + ketamine (20 mg) + naloxone (2 μg; M + R + K + N), respectively. All patients received patient-controlled epidural analgesia (PCEA) with different pain regimens to control subsequent postoperative pain for 3 days following surgery. During the 3-day period following surgery, PCEA consumption (mL), numerical rating scale (NRS) score while cough/moving, and analgesic-related adverse effects were recorded. RESULTS: Total PCEA consumption for the 3-day observation period was 161.5±17.8 mL, 103.2±21.7 mL, 152.4±25.6 mL, and 74.1±16.9 mL for Groups I, II, III, and IV, respectively. (p < 0.05). The cough/moving NRS scores were significantly lower in Group IV patients than Groups I and III patients at 4 hours, 12 hours, and on Days 1 and 2 following surgery except for Group II (p < 0.05). CONCLUSION: Preincisional and postoperative epidural M + R + K + N treatment provides an ideal postoperative pain management than preincisional and postoperative epidural M + R, M + R + K, and M + R + N treatments in upper abdominal surgery.