To compare intraoperative and postoperative clinical properties of levobupivacaine and ropivacaine for sciatic nerve block, 50 ASA physical status I and II patients undergoing hallux valgus repair received a femoral nerve block with 15 mL of 2% mepivacaine. They were then randomly allocated in a double-blinded fashion to receive a sciatic nerve block with either 0.5% levobupivacaine (n = 25) or 0.5% ropivacaine (n = 25). An independent blinded observer evaluated the onset time of surgical anesthesia as well as the quality of the surgical block and postoperative analgesia. The median (range) onset time of surgical block at the sciatic nerve distribution was 30 min (5-60 min) with levobupivacaine and 15 min (5-60 min) with ropivacaine (P = 0.63). Four patients (two patients in each group) received a supplementary ankle block by the surgeon just before the beginning of surgery. All four patients also received IV fentanyl supplementation, but in three of them, propofol infusion was required to complete surgery (two in the Levobupivacaine group [8%] and one in the Ropivacaine group [4%]; P = 0.99). In six patients of the Levobupivacaine group (24%) and five patients of the Ropivacaine group (20%), IV fentanyl supplementation was required to complete surgery (P = 0.99). No differences in the time to recovery of sensory and motor function were observed between the two groups, whereas median (range) duration of postoperative analgesia was 16 h (8-24 h) with levobupivacaine and 16 h (8-24 h) with ropivacaine (P = 0.83). We conclude that 0.5% levobupivacaine and 0.5% ropivacaine provide comparable surgical anesthesia and postoperative analgesia.
Implications: No studies have compared the clinical properties of levobupivacaine with those of ropivacaine when providing sciatic nerve block for hallux valgus repair. Results from this prospective, randomized, double-blinded study demonstrate that 20 mL of either 0.5% levobupivacaine or 0.5% ropivacaine provide comparable surgical block with prolonged postoperative analgesia.