Comparison of dexmedetomidine and clonidine as an adjuvant to levobupivacaine in supraclavicular brachial plexus block

Abstract

Adjuncts to local anaesthetics for brachial plexus block enhances the quality and duration of analgesia. The purpose of this study was to compare two alpha-2 agonists clonidine and dexmedetomidine, when added as adjuvant to ropivacaine, in respect to onset, duration of sensory and motor block along with duration of analgesia. After informed consent, Sixty ASA I and II patients scheduled for elective upper limb surgeries under supraclavicular brachial plexus block in R L Jalappa Hospital were divided into two equal groups in a randomized, double-blinded fashion. To ropivacaine 29 ml (0.5%), Group C received clonidine 1 ml (50 μg) and Group D received dexmedetomidine 1ml (50μg). Onset and duration of sensory and motor block, duration of analgesia were studied in both the groups. Both groups were comparable with regard to age, sex distribution, pulse rate and mean arterial blood pressure. There was no statistically significant difference. Onset of sensory and motor blockade was faster in Group D, which is statistically significant. The Duration of sensory block and motor block, analgesia was also greatest in group D, which is statistically significant. There was no statistically significant difference between two groups in number of rescue analgesia requirement during first 24 hrs. There were no adverse events noted in either group. All patients were haemodynamically stable without requiring anaesthetist's intervention. Dexmedetomidine when added to ropivacaine in supraclavicular brachial plexus block had faster onset, greater duration of sensory and motor block and also, the duration of analgesia, than clonidine. Dexmedetomidine is better adjuvant than clonidine when added as adjuvant to ropivacaine in supraclavicular brachial plexus block.