Orthopedics · Medical Literature
Effect of Ultrasound-Guided Sciatic and Saphenous Nerve Blocks on Analgesia During General Anaesthesia for Ankle Fracture Surgery: A Randomised Controlled Trial.
Abstract
Background and Objectives: Ultrasound-guided sciatic and saphenous nerve blocks are widely used as analgesic alternatives for multimodal analgesia. However, how to objectively quantify the opioid- and anaesthetic-sparing effects of an additional peripheral nerve block in patients undergoing ankle fracture surgery under general anaesthesia remains unclear. This study aimed to evaluate their efficacy in managing postoperative pain and opioid-sparing effects following ankle fracture surgery. Materials and Methods: Patients scheduled for ankle fracture surgery were randomly assigned to the nerve block (n = 30) or control group (n = 30). The primary outcome was the postoperative numeric rating scale (NRS) score. The secondary outcomes included the total doses of remifentanil and propofol, Quality of Recovery-40 Korean (QoR-40K) scores, and self-reported patient satisfaction. Results: The NRS score immediately after surgery was significantly lower in the nerve block group compared with that in the control group (2.6 ± 2.5 vs. 6.2 ± 2.6; p < 0.001). The total remifentanil dose required during surgery was also significantly lower in the nerve block group than in the control group (1148.1 ± 391.8 vs. 1487.4 ± 798.8; p = 0.041). However, the patient satisfaction scale (3 [IQR, 2-4] vs. 3 [IQR, 2-4]; p = 0.206) and QoR-40K score 24 h after surgery (169 [IQR, 155-184] vs. 175 [IQR, 154-165]; p = 0.324) did not differ significantly between the two groups. Conclusions: Ultrasound-guided sciatic and saphenous nerve blocks significantly reduced immediate postoperative pain and intraoperative remifentanil consumption under qNOX (quantitative nociception index)-guided general anaesthesia during ankle fracture surgery.
Clinical relevance
Ankle fracture surgery is associated with significant postoperative pain, and optimizing multimodal analgesia to reduce intraoperative and postoperative opioid consumption remains a clinical priority. This randomized controlled trial addresses the gap in objective, quantitative evidence for the opioid- and anaesthetic-sparing effects of ultrasound-guided peripheral nerve blocks (sciatic and saphenous) when added to qNOX-guided general anaesthesia. The findings are directly relevant to orthopedic and anesthesiology teams seeking evidence-based regional analgesia strategies for lower extremity fracture surgery.
Key findings
1. Immediate postoperative NRS pain scores were significantly lower in the nerve block group vs. control (2.6 ± 2.5 vs. 6.2 ± 2.6; p < 0.001), representing a clinically meaningful reduction of 3.6 NRS points. 2. Total intraoperative remifentanil consumption was significantly reduced in the nerve block group compared to control (1148.1 ± 391.8 mcg vs. 1487.4 ± 798.8 mcg; p = 0.041), demonstrating a statistically significant opioid-sparing effect. 3. Patient satisfaction scores did not differ significantly between the nerve block and control groups (median 3 [IQR 2–4] vs. 3 [IQR 2–4]; p = 0.206). 4. Quality of Recovery-40 Korean (QoR-40K) scores at 24 hours postoperatively were not significantly different between groups (median 169 [IQR 155–184] vs. 175 [IQR 154–165]; p = 0.324). 5. The study was adequately powered with 30 patients per arm (n = 60 total), and nerve block efficacy was objectively quantified using the qNOX quantitative nociception index under general anaesthesia, adding methodological rigor beyond standard clinical endpoints. 6. No NNT or NNH values were reported in the abstract; effect sizes are limited to mean/median differences as described above.
Practice implications
Anesthesiologists performing ankle fracture surgery under general anaesthesia should consider adding ultrasound-guided sciatic and saphenous nerve blocks as part of a multimodal analgesic protocol, given the significant reduction in immediate postoperative pain (NRS reduction ~3.6 points) and intraoperative remifentanil requirements (~23% reduction). Patient selection should focus on those undergoing ankle fracture surgery where the combined sciatic and saphenous nerve territory provides comprehensive ankle coverage; qNOX monitoring may be a useful adjunct to objectively titrate opioid dosing in this context. However, clinicians should counsel patients that regional blocks in this setting did not demonstrate significant improvements in 24-hour quality of recovery or overall patient satisfaction scores, suggesting the benefit is primarily confined to the immediate perioperative window and that broader recovery optimization requires additional multimodal strategies.