Dexmedetomidine and Clonidine as an Adjuvant to Bupivacaine in Ultrasound Guided Supraclavicular Brachial Plexus Block- A Randomised Clinical Trial

Introduction: Alpha‑2 agonists are used as adjuvants with Local Anaesthetic (LA) agents to prolong the duration of regional nerve blocks. Aim: To compare clonidine and dexmedetomidine as an adjuvant to bupivacaine in supraclavicular brachial plexus block with respect to onset and duration of sensory and motor block and duration of analgesia. Materials and Methods: In this randomised clinical trial, 70 American Society of Anesthesiologists (ASA) class I and class II patients, scheduled for elective upper limb surgeries under ultrasound guided supraclavicular brachial plexus block, were divided into two equal groups. Group-I received clonidine 1 μg/ kg and group-II received dexmedetomidine 1 μg/kg added to bupivacaine 0.5% (20 mL). Onset and recovery time of sensory and motor block, duration of analgesia were studied in both the groups. Data analysis was done using Analysis of variance (ANOVA) and Student t-test for analysis of continuous data and Chi-square test used to know the difference of significance in categorical data. Results: A total of 70 subjects between age group of 18-60 years were included in the study. The onset of sensory blockade was faster in group-I (3.54±0.74 min) than group-II (3.86±0.88 min) but statistically not significant. The onset of motor blockade was faster in group-I (5.4±1.12 min) than group-II (6.34±1.14 min) and difference was statistically significant. Duration of sensory blockade was longer in group-I (616.23±62.05 min) than group-II (574.71±61.14 min) and motor blockade in group-I (635.86±57.82 min) was longer than group-II (562.80±66.89 min) and the differences were statistically significant. The duration of analgesia was longer in group-I (797.29±108.06 min) than group-II (695.00±91.14 min) and the difference was statistically significant. Conclusion: Dexmedetomidine shortens the onset, prolongs the duration of sensory and motor block and also provides longer postoperative analgesia as compared with clonidine when used as an adjuvant to bupivacaine in ultrasound guided supraclavicular brachial plexus block