Effect of Ultrasound-Guided Sciatic and Saphenous Nerve Blocks on Analgesia During General Anaesthesia for Ankle Fracture Surgery: A Randomised Controlled Trial

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.