COMPARISON OF CLONIDINE AND DEXMEDETOMIDINE AS AN ADJUVANT TO 0.5% BUPIVACAINE IN SUPRACLAVICULAR BRACHIAL PLEXUS BLOCK: A RANDOMISED PROSPECTIVE DOUBLE-BLIND STUDY

Abstract

Background and Objectives: Alpha-2 agonists are used as adjuvant with local anaesthetic agents to prolong the duration of spinal, epidural and peripheral nerve blocks as well as to prolong the duration of post operative analgesia. We performed a study to compare clonidine(1ug/kg) and dexmedetomidine (1ug/kg) as an adjuvant to 0.5% bupivacaine in supraclavicular brachial plexus block. Methods: Eighty ASA I and II patients scheduled for elective upper limb orthopaedic surgeries under supraclavicular brachial plexus block were divided into two  groups(n=25 each) in a randomized, double-blinded fashion. Group C received clonidine 1 ?g/kg and Group D received dexmedetomidine 1 ?g/kg added to bupivacaine 0.5% (30 cc). Onset and recovery time of sensory and motor block, as well as duration of analgesia were studied in both the groups. Results: Duration of sensory block and motor block was 220.12 ±50.3 and 280.1± 20.12 min respectively in group C, while it was 410.34± 60.12 and 460.4 ± 50.56 min respectively in group D and hence both were significantly prolonged in group D.  No statistically significant difference was seen in onset of sensory and motor block between the two groups. The duration of analgesia i.e. time to requirement of rescue analgesia was 270.4± 56.7 mins and 452.7 ±64.23 mins in group C and D respectively and  this difference was statistically significant (P=0.001). Conclusion: Addition of dexmedetomidine to bupivacaine 0.5% in supraclavicular brachial plexus block prolonged the duration of sensory and motor block as well as the duration of analgesia when compared with clonidine.

Keywords: Clonidine, dexmedetomidine, supraclavicular block