Randomized trial of a pain control infusion pump following inguinal hernia repair

Continuous ambulatory analgesia following various surgical procedures is gaining popularity. The purpose of the present paper is to evaluate this form of analgesia following open anterior inguinal hernia repair by way of a pain control infusion pump (PCIP).

Forty-eight consecutive patients scheduled for inguinal hernia repair were enrolled in a double-blind, randomized, placebo-controlled trial. Following the repair, a catheter was placed in the wound connected to an external PCIP, delivering either ropivacaine or normal saline at a fixed rate of 4 mL/ h. Regular 4-hourly postoperative pain observations according to a Visual Analogue Score (VAS) and any rescue opioid requirements were recorded, at different levels of mobility.

Data analysis included 23 (ropivacaine) and 24 (saline) patients in each group, with one exclusion. There were no adverse effects of the PCIP in either group. Patients in the ropivacaine group ('active pump') had lower mean pain scores and less rescue analgesia compared to the saline group ('placebo pump'). This clinical effect was found to be more striking at increased levels of mobility. Importantly, no patients in the ropivacaine group required any rescue analgesia after the first 4-h block postoperatively.

The PCIP provided safe and adequate analgesia following inguinal hernia repair. It provided effective analgesia especially when patients were mobilizing. This has implications for earlier discharge from hospital and associated cost-savings.