Effects of clonidine and Dexmedetomidine on ropivacaine in ultrasound guided supraclavicular brachial plexus block

Abstract

Background: Several clinical studies have shown that clonidine prolongs sensory motor blockade when used as adjuvant to ropivacaine but it has its own limitations.Aim: To evaluate the effect of clonidine and dexmedetomidine on ropivacaine, for supraclavicular brachial plexus blockade.Methods: In a prospective randomised double blind study ultrasound guided supraclavicular brachial plexus blockade was performed in 100 patients using clonidine and dexmedetomidine with ropivacaine. Group C had 1 μg/kg clonidine(1ml) and in Group D 1 μg/kg dexmedetomidine(1ml) added to 30 ml of ropivacaine(0.5%). 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 D was 2.44 ± 1.7 min and in group C was 4.85 ± 1.55 min, which was statistically significant. Patients of group D had a mean motor onset time 4.35 ± 1.8 min and patients of group C had a mean motor onset time 8.55 ± 1.64 min, the difference being statistically significant. Mean duration of sensory block in group D
was 584.15 ± 63.4 min and in group C was 490.85 ± 72.65 min, which was statistically significant. Patients in group D had a mean duration of motor block 450 +60.3 min and patients in group C had a mean duration of motor block 330.45+68.7 min, which was statistically significant.Conclusion: The addition of dexmedetomidine to ropivacaine increases the duration of motor and sensory block in brachial plexus blockade