Intermittent wound perfusion for postoperative pain relief following upper abdominal surgery: a surgeon's perspective.

BACKGROUND

Although there are many methods for postoperative pain management, implementation may be limited in some settings due to practical or financial constraints. Simple, inexpensive and easily implemented analgesic methods may improve access to effective pain relief.

METHODS

Fifty patients undergoing truncal vagotomy and gastrojejunostomy for pyloric stenosis secondary to chronic duodenal ulceration were studied in this prospective randomized trial. Subjects were assigned to receive either wound perfusion with 8 mL of 0.25% bupivacaine every 5 hours through a catheter placed subcutaneously or intravenous pethidine 0.2 mg/kg on demand for postoperative pain relief. Postoperative pain scores at rest were measured by visual analog scale and the opioid requirement at 0-12 hours, at 12-24 hours and at 24-36 hours were compared. Changes in respiratory parameters were also compared between the two groups.

RESULTS

Pain scores at 0-12 hours were significantly lower in the wound perfusion group compared with the intravenous pethidine group (5.7 +/- 1.3 vs. 4.3 +/- 1.2, mean +/- SD; P < 0.001). The number of doses of analgesic required in the wound perfusion group was significantly lower compared with the controls during the 36 hours of study (3.5 +/- 1.3 vs. 1.4 +/- 1.0, P < 0.001). There were no differences in respiratory parameters, vital capacity, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and peak expiratory flow rate between the two groups. The FEV1:FVC ratio, however, was significantly higher in the intravenous pethidine group. There were no wound complications due to catheter placement or systemic toxicity due to the anesthetic.

CONCLUSION

Intermittent wound perfusion with 0.25% bupivacaine is a safe and efficient method to reduce pain scores and opioid requirement in the early postoperative period. Wound perfusion, however, had no beneficial effect on the postoperative respiratory function.