Evaluation of continuous infusion of 0.5% bupivacaine by elastomeric pump for postoperative pain management after open inguinal hernia repair

Abstract

Postoperative pain management and narcotic usage after inguinal hernia repair is an important concern for anesthesiologists and surgeons. Regional anesthesia incisional infiltration techniques may reduce the need for systemic medications. Double-blind study of 52 patients undergoing open hernia repair with the Prolene Hernia System prospectively randomized to receive either 0.5% bupivacaine or saline continuously for 48 hours at 2 mL/hour through use of an elastomeric continuous infusion pump (ONQ Pain Relief System). Outcomes measured over the 120 hours postoperatively were: narcotic use, Visual Analogue Scale pain scores, site inflammation (visual inspection), and side effects. Comparisons between the groups were made by applying the Mann-Whitney rank sum test and analysis of variance with treatment as a fixed effect in the model. In the bupivacaine group, 24% (versus 4% in the placebo group) required no narcotics (p < 0.05). Daily and total narcotic usages for all 5 study days were significantly less (p < 0.05) in the bupivacaine group. There were no reports of complications at the catheter-insertion site or surgical-wound site. Demonstrable benefits include reduction of narcotic usage and pain with no apparent increase in the risk of infection or complication. Continuous infusion of 0.5% bupivacaine at 2 mL/h through the ONQ pump is a safe and effective adjunct in postoperative pain management for open inguinal hernia repair. This represents a viable and possibly superior option for prolonged pain management, minimizing use of narcotics in patients undergoing this procedure.