Effect of liposomal bupivacaine for sciatic nerve block on opioid use in patients undergoing maxillofacial reconstruction with free fibular flap: a randomized, controlled trial

We investigated the efficacy and safety of preoperative popliteal sciatic nerve block (PSNB) using liposomal bupivacaine (LB) to reduce perioperative opioid consumption and improve recovery quality in patients undergoing maxillofacial reconstruction with a free fibular flap. A total of 74 patients were randomly allocated into two groups. The PSNB group received ultrasound guided PSNB using 133 mg of LB after anesthesia induction. In the control group, patients underwent nerve block preparation procedures without puncture or drug injection. The primary endpoint was cumulative opioid consumption during the perioperative period (from anesthesia induction to 48 h post-surgery). The secondary endpoints were the total incidence of moderate to severe pain during the 48 h postoperative period; the incidence of moderate to severe pain during different time periods after surgery; the incidence of PONV within 48 h after surgery; subjective sleep quality within 2 days after surgery; the length of post-surgical hospital stay; all-cause in-hospital mortality; and the incidence of other complications during hospitalization. There was no significant difference in cumulative opioid consumption between the control group (3020.0 [2163.0, 3569.5] µg of remifentanil equivalents) and the PSNB group (2856.0 [2204.0, 3771.0] µg; p = 0.863). The incidence of moderate to severe pain at the donor site within 48 h after surgery was significantly lower in the PSNB group (3 [8.1%] of 37 patients) than in the control group (18 [48.6%] of 37 patients; p < 0.001). The consumption of rescue opioids was significantly reduced in the PSNB group (0 [0, 50]) compared with that in the control group (50 [0, 100]; p = 0.007). The subjective sleep quality numeric rating scale score was significantly lower in the PSNB group than in the control group (day of surgery: 6.0 [5.0, 8.0] vs. 8.0 [6.0, 9.0], p = 0.029; postoperative day 1: 5.0 [4.0, 5.0] vs. 7.0 [5.5, 7.5], p < 0.001; postoperative day 2: 5.0 [4.0, 5.5] vs. 6.0 [5.0, 7.5], p = 0.001). The incidence of postoperative nausea and vomiting was significantly lower in the PSNB group (0 [0.0%]) compared with that in the control group (5 [13.5%]; p = 0.021). There was no significant difference in the incidence of adverse events between the two groups. Preoperative administration of PSNB by LB did not spare opioids during the intraoperative period, but significantly relieved postoperative pain at the donor site, reduced rescue opioid consumption, and improved postoperative sleep quality, without additional adverse events. Clinicaltrials.gov. Identifier ChiCTR2400080944, 19 February 2024.