Comparison of Efficacy and Safety of 0.5% Bupivacaine and 0.5% Ropivacaine for Combined Femoral Nerve Block and Sciatic Nerve Block (Anterior Approach): A randomized controlled trial

Introduction: Regional blocks are increasingly the preferred for a wide range of lower limb surgical procedures over spinal and epidural anesthesia. Various local anesthetic agents in different concentrations have been used for combined femoral and sciatic nerve block. But the existing evidence is inconclusive on the ideal anesthetic agent and its concentration. The available evidence on relative merits of different anesthetic agents in Indian Population is even limited. Objectives: To compare the safety, efficacy and hemodynamic parameters of 0.5% Bupivacaine and 0.5% Ropivacaine during combined femoral and sciatic nerve block. Materials and Method: The study was a randomized double-blind controlled trial of 36 subjects, randomly assigned to 0.5% Bupivacaine and 0.5% Ropivacaine groups. Subjects between 18 to 60 years belonging to ASA grade I and II, posted for various below knee lower limb procedure were included. Time is taken for onset of sensory and motor block, duration of sensory and motor block was compared across the study groups using independent sample t-test. The occurrence of complications and hemodynamic parameters also were compared. Results: In the current study, no statistically significant difference was observed in the time taken for onset of sensory block in either femoral nerve (13.39 and 13.69 minutes in Bupivacaine and Ropivacaine groups respectively, p value 0.39) or sciatic nerve (17.19 and 17.14 minutes, p value 0.89) The motor blockade took 21.28 and 21.64 minutes respectively in both the study groups (P value 0.53). In the current study, the duration of sensory block was slightly longer in Bupivacaine group, as compared to Ropivacaine group (933.67Vs 924.22, p value 0.19), but this difference was statistically not significant. The duration of motor block was significantly longer in Bupivacaine group (243.78 Vs 189.11, p value 0.001), as compared to Ropivacaine group. None of the study subjects in both the groups have reported any complications. There were no significant differences in hemodynamic parameters across the groups. Conclusions 1. Both sensory and Motor block onset time were similar with 0.5% Bupivacaine and Ropivacaine in combined femoral and sciatic nerve block. The duration of sensory block also was comparable across the two groups 2. Bupivacaine had comparatively longer duration of motor block, as compared to Ropivacaine group 3. There were no clinically or statistically significant differences in hemodynamic parameters.