The Effects of Two Different Doses of Clonidine as Adjuvant to Ropivacaine in Supraclavicular Brachial Plexus Block- A Randomized Controlled Study

Background: Several clinical studies have shown that clonidine prolongs sensory motor blockade when used with bupivacaine but ideal doses of clonidine on ropivacaine is not well defined and to evaluate the effect of two doses of clonidine on ropivacaine, for supraclavicular brachial plexus blockade. Methods: In a prospective randomized double blind study supraclavicular brachial plexus blockade were performed in 80 patients using 35 ml ropivacaine (0.5%). Group A (n=40) had 2 μg/kg clonidine and in Group B (n=40) 1 μg/kg clonidine added to ropivacaine. Sensory and motor blockade was assessed every 5 min till 30 min and at 15 min interval thereafter. Results: Mean sensory onset time in group A was 10.42 ± 5.5 min and in group B was 15.83 ± 6.51 min, which was statistically significant. Patients of group A had a mean motor onset time 14.35 ± 7.8 min and patients of group B had a mean motor onset time 18.53 ± 7.61 min, the difference being statistically significant. Mean duration of sensory block in group A was 484.13 ± 63.1 min and in group B was 390.83 ± 72.63 min, which was statistically significant. Patients in-group A had a mean duration of motor block 550 +60.1 min and patients in group B had a mean duration of motor block 430.43+68.5 min, which was statistically significant. Conclusion: The addition of clonidine in dose of 2 μg/kg to ropivacaine for brachial plexus blockade, increases the onset and duration of motor and sensory block significantly.