Comparison of 0.5% Ropivacaine and 0.5% Levobupivacaine for Sciatic Nerve Block Using Labat Approach in Foot and Ankle Surgery.

Objective: Compared to ropivacaine, levobupivacaine is more lipophilic and a more potent vasoconstrictor. The study was conducted to compare the effect of 0.5% ropivacaine and 0.5% levobupivacaine in sciatic nerve block using conventional Labat approach in foot and ankle surgery.

Methods: A prospective double-blind, randomised study was carried out in 100 patients of either sex, aged between 20 to 60 years, and American Society of Anesthesiologist (ASA) grades I and II. Patients were randomly allocated into groups R and L of 50 each with 0.5% ropivacaine and 0.5% levobupivacaine, respectively, for sciatic nerve block using the Labat approach. We assessed the onset and duration of sensory and motor block, duration of analgesia, consumption of analgesic, and any untoward effect over 24 hours.

Results: Both the groups were comparable with regard to demographic variables and onset of sensory and motor block (p>0.05). Group L compared to group R had significantly longer median (95% confidence interval) duration of sensory block (647.50 min [624.99-674.41] vs. 535 min [524.77-559.83], respectively; p<0.0001) as well as motor block (1065.0 min [1054.5-1068.90] and 945 min [947.13-1013.30], respectively; p<0.0001). Postoperative analgesia also lasted significantly longer in group L compared to group R (1320 min [1273.4-1321.8] vs. 840 min [759.23-812.77]; p<0.0001]). Patients in group L had significantly better visual analogue scale (VAS) score and lesser consumption of analgesics (p<0.0001). None of the groups developed any adverse effect over the observation period.

Conclusion: Levobupivacaine provides prolonged postoperative analgesia in sciatic nerve block with reduction in postoperative analgesic consumption.