Comparative Study of the Efficacy of Dexmedetomidine and Fentanyl as Adjuvants to Ropivacaine in Ultrasound-Guided Supraclavicular Brachial Plexus Block

Objective: Supraclavicular brachial plexus block is preferable to general anaesthesia in upper limb surgeries. Various adjuvants have been added to improve the quality of the block and prolong postoperative analgesia. The aim of the present study was to compare the onset and duration of sensory and motor blockade with the quality of perioperative analgesia and postoperative complications provided by dexmedetomidine and fentanyl as adjuvants to ropivacaine under ultrasound (USG) guidance in supraclavicular block. Methods: A total of 80 patients with American Society of Anesthesiologists grade I/II scheduled for elective upper limb surgeries were randomly allocated into two groups. Group A received 30 mL of 0.5% ropivacaine with 1 mu g kg(-1) dexmedetomidine, and group B received 30 mL of 0.5% ropivacaine with 1 mu g kg(-1) fentanyl for supraclavicular brachial block using USG guidance. The onset and duration of sensory and motor block, time for requirement of rescue analgesia and adverse events during the perioperative period were noted. Results: The onset of sensory blockade was 13.95 +/- 1.34 min in the dexmedetomidine group and 14.18 +/- 1.41 min in the fentanyl group. There was a highly significant statistical difference in terms of the duration of the sensory blockade, i.e. 801.75 +/- 46.07 min with dexmedetomidine compared to 590.25 +/- 40.41 min with fentanyl (p<0.0001). The duration of motor blockade was highly statistically significant with 649.56 +/- 42.73 min in group A compared to 456.75 +/- 32.93 min in group B. Conclusion: Dexmedetomidine prolongs the duration of sensory and motor block and postoperative analgesia as compared to fentanyl when used as an adjuvant to ropivacaine in supraclavicular brachial plexus block and is not associated with any major adverse events.