Continuous wound infusion of local anesthetic for the control of pain after elective abdominal colorectal surgery

PURPOSE: Local anesthetic wound infusion has been investigated in recent years as a potential alternative to standard analgesic regimens after major surgery. This study investigates the efficacy of a continuous wound infusion of ropivacaine in conjunction with best practice postoperative analgesia after midline laparotomy for abdominal colorectal surgery. METHODS: We performed a randomized, participant and outcome assessor-blinded, placebo-controlled trial on patients presenting for major abdominal colorectal surgery at our institution between December 2003 and February 2006. Patients were allocated to receive ropivacaine 0.54 percent or normal saline via a dual catheter Painbuster Soaker (TM) (I-Flow Corporation, OH, USA) continuous infusion device into their midline laparotomy wound for 72 hours postoperatively. RESULTS: A total of 310 patients were included in this study. The continuous wound infusion of ropivacaine after abdominal colorectal surgery conveys minimal benefit compared with saline wound infusion. No statistically significant difference could be shown for: pain at rest, morphine usage, length of stay, mobility, nausea, or return of bowel function. There was a small, statistically significant difference in mean pain on movement on Day 1 for the ropivacaine group (adjusted mean difference -0.6 (range, -1.08 to -0.13)). Although this trend continued on Days 2 and 3, the differences between groups were no longer statistically significant. CONCLUSIONS: Management of pain after major abdominal colorectal surgery is best achieved through adopting a multimodal approach to analgesia. Delivery of ropivacaine to midline laparotomy wounds via a Painbuster Soaker (TM) device is safe, but we have not demonstrated any significant clinical advantage over current best practice.