Effects of dexmedetomidine as an adjuvant to ropivacaine in ultrasound-guided supraclavicular brachial plexus Block: A prospective, randomized, double-blind study

BACKGROUND AND AIMS: Various adjuvants have been added to local anesthetics in single shot blocks so as to prolong the duration of postoperative analgesia. The present study was conceived to evaluate the effect of dexmedetomidine as an adjuvant to ropivacaine for institution of supraclavicular brachial plexus block. MATERIAL AND METHODS: Ninety adult patients (ASA physical status I, II) scheduled for elective upper limb surgeries under ultrasound-guided subclavian perivascular brachial plexus block were allocated randomly into two groups; the study was designed in double-blind fashion. All patients received 20 ml 0.75% ropivacaine, in addition, patients in group A (n = 43) received 2 ml 0.9% normal saline and those in group B (n = 44) received dexmedetomidine (1 μg/kg body weight); total volume was made up to 22 ml with sterile 0.9% saline in both groups. The onset and duration of sensory and motor blocks, time to first request of analgesia, total dose of postoperative analgesic administration, and level of sedation were also studied in both the groups. All the data were analyzed by using unpaired t-test. P < 0.05 was considered significant. RESULTS: Sensory and motor block durations (613.34 ± 165.404 min and 572.7 ± 145.709 min) were longer in group B than those in group A (543.7 ± 112.089 min and 503.26 ± 123.628 min; P < 0.01). Duration of analgesia was shorter in group A (593.19 ± 114.44 min) compared to group B (704.8 ± 178.414 min; P < 0.001). CONCLUSION: Addition of dexmedetomidine to 0.75% ropivacaine in supraclavicular brachial plexus block significantly prolongs the duration of analgesia.