Perisciatic infusion of ropivacaine and analgesia after hallux valgus repair.

Background: Moderate to severe pain after hallux valgus repair can be successfully treated with a continuous popliteal sciatic nerve block in ambulatory patients. Different anesthesiologists use various infusion rates for this purpose. The aim of this study was to compare the analgesic efficacy of two infusion rates of ropivacaine 2 mg/ml: 5 and 8 ml/h.

Methods: Forty ambulatory patients who underwent chevron osteotomy for hallux valgus were randomized to receive perisciatic infusion of ropivacaine 2 mg/ml at a rate of either 5 ml/h (5 ml group) or 8 ml/h (8 ml group). All patients received standard general anesthesia for surgery after the sciatic popliteal and the single-shot saphenus nerve blocks were performed. Verbal rating scale (VRS) scores for pain, sleep disturbances, opioid consumption and side effects were monitored for 3 post-operative days.

Results: No significant difference was found in the primary end point worst pain on the first post-operative day with VRS scores of 2.5 (0-8) vs. 5.5 (0-10) for the 5 and 8 ml/h groups, respectively (P=0.53). Post-operative pain was satisfactory in both groups, with an average VRS score ≤4 for 60-62 h.

Conclusions: We found no significant difference in the analgesic effect between two perisciatic infusion rates of ropivacaine 2 mg/ml (5 vs. 8 ml/h) in ambulatory patients who underwent chevron osteotomy.