A comparative study of analgesic efficacy of intravenous dexmedetomidine and perineural dexmedetomidine as an adjuvant to ropivacaine in supraclavicular block

Introduction: Dexmedetomidine is a frequently used adjunct to local anesthetics in various blocks because of its proven benefits. With this study we aim to compare the efficacy of dexmedetomidine via different routes (intravenous versus perineural) as an adjuvant to ropivacaine in supraclavicular brachial plexus block in patients undergoing upper limb surgery. Material and method: The study was conducted on 70 adult patients undergoing upperlimb surgery, randomized into 2 groups. Group ID (n=35) received USG guided supraclavicular block with 30 ml volume (28 ml of 0.50% ropivacaine plus 2ml of normal saline) and 1 μg/kg of dexmedetomidine in 50 ml of normal saline infusion intravenously. Group PD (n=35) recieved USG guided supraclavicular block 30 ml volume (28 ml of 0.50% ropivacaine plus 1 μg/kg of dexmedetomidine in 2ml of normal saline) and 50 ml of normal saline infusion. The onset and duration of sensory and motor block, duration of analgesia, hemodynamic parameters and side effects were recorded. Results: The demographic profile was comparable in both the groups. The group PD had faster onset of sensory (p=0.002) and motor blockade (p=0.001), longer duration of sensory (p=0.0009) and motor (p=0.005) blockade and longer duration of analgesia (p=0.010) as compared to group ID. Conclusion Dexmedetomidine when used perineurally as an adjuvant in USG guided supraclavicular brachial plexus block shortens the onset of motor and sensory block, prolongs the duration of motor and sensory blocks and increases the duration of analgesia when compared with intravenous dexmedetomidine.