Efficacy of Intravenous versus Perineural Dexmedetomidine as an Adjunct to Levobupivacaine in Supraclavicular Brachial Plexus Block: A Randomized Comparative Study

Background and Aim: Dexmedetomidine, an α2-adrenergic agonist, is increasingly used as an adjuvant in regional anaesthesia to improve block quality and prolong postoperative analgesia. However, the optimal route of administration—intravenous versus perineural—remains under debate. This study aimed to compare the efficacy of intravenous versus perineural dexmedetomidine when used as an adjunct to levobupivacaine in ultrasound-guided supraclavicular brachial plexus blocks. Material and Methods: A prospective randomized study was conducted on 100 adult patients undergoing elective upper limb surgeries. Patients were divided into two groups (n=50 each). Group DP received perineural dexmedetomidine (1 µg/kg) with levobupivacaine, and Group DIV received intravenous dexmedetomidine (1 µg/kg) with levobupivacaine alone perineurally. Primary outcomes included onset time and duration of sensory and motor block. Secondary outcomes were sedation, hemodynamic stability, and duration of analgesia. Results: Onset of both sensory and motor block was significantly faster in Group DIV compared to Group DP (p < 0.001). However, the duration of sensory and motor block, as well as postoperative analgesia, was significantly longer in the DP group (p < 0.001). No significant adverse effects were observed in either group. Conclusion: Intravenous dexmedetomidine leads to a quicker onset of block, while perineural administration offers prolonged analgesia and block duration. Both routes are safe and effective, and the choice may be tailored based on surgical requirements and desired clinical outcomes.