Continuous Femoral Nerve Analgesia after Unilateral Total Knee Arthroplasty: Stimulating versus Non-Stimulating Catheters

摘要

Continuous femoral analgesia provides extended pain relief and improved functional recovery for total knee arthroplasty (TKA). Successful continuous peripheral nerve analgesia depends on the catheter proximity to the target nerve. If the catheter is not close to the nerve, high infusion rates may be required to provide analgesia or analgesia may be sub-optimal. Stimulating catheters may allow more accurate placement of catheters in close proximity to the nerve. This randomized prospective study examined the use stimulating catheters versus non-stimulating catheters in 41 patients undergoing TKA. All patients had intravenous patient controlled anesthesia (IVPCA) for supplementary pain relief. The principal aim of the trial was to examine whether the use of a stimulating catheter allowed the use of lesser amounts of local anesthetics than a non-stimulating catheter. Additional parameters examined included post-operative pain scores, opioid use, side effects and acute functional orthopedic outcomes. Analgesia was good in both groups, but there were no statistically significant differences in the amount of ropivacaine administered; the median amount of ropivacaine given to patients in the stimulating catheter group was 8.2 ml/h vs. 8.8 ml/h for patients with non-stimulating catheters, P = 0.26 (median difference -0.6; 95% confidence interval, -2.3 to 0.6). No significant differences between the treatment groups were noted for the amount of fentanyl dispensed by the IVPCA, numeric pain rating scale scores, acute functional orthopedic outcomes, side effects or amounts of oral opioids consumed.>Implications: For total knee arthroplasty, there seems to be no significant advantage for the use of stimulating catheters over traditional non-stimulating catheters in continuous femoral nerve blocks.