Background Post-operative pain after an above-knee amputation is often severe, and in the elderly patients the adverse effects of post-operative opioids are evident. We hypothesized that continuous perineural local anesthetic infusion (CPI) combined to a wound infusion will reduce acute pain and opioid consumption compared to placebo after above knee amputation.

Methods Ninety-three patients going through an above knee amputation were recruited for this randomized, controlled trial. Two catheters were placed, one to the sciatic nerve sheath and one under the fasciae during the amputation. After two 10 mL boluses of ropivacaine 0.75% a post-operative infusion of ropivacaine 0.2% or placebo (NaCl 0.9%) at 2 mL/h was administered for 72 hours to both catheters. The primary outcome was average stump pain during the first 5 days.

Results The mean intensity of stump pain during the first five post-operative days was 1.4 (0.8) in the CPI group and 1.9 (0.9) in the placebo group on VRS, mean (SD), P = .006. The opioid consumption on first five post-operative days did not differ between the groups.

Conclusion A combination of continuous perineural and wound local anesthetic infusion seems to diminish the intensity of stump pain after above knee amputation.