Background: We compared the effects of adding dexmedetomidine and magnesium to local anesthetics in ultrasound(US) guided supraclavicular brachial plexus block(SBPB). Onset and duration of sensory and motor block along with the duration of analgesia were the primary endpoints.
Patients and Methods: Thirty patients posted for upper limb surgeries were enrolled for a comparative randomized prospective clinical study. Patients were divided into two groups, dexmedetomidine group (D) and magnesium group (M). In group D (n= 15) patients were administered 24ml volume of local anesthetics(LAs) (lidocaine 2% + bupivacaine 0.5% 1:1 mixture) +100mcg dexmedetomidine in 1ml volume. Patients in group M (n= 15) were administered 24ml volume of LAs (lidocaine 2% +bupivacaine 0.5% 1:1 mixture) + magnesium Sulphate 100 mg in 1 ml volume. Onset, duration of sensory and motor blocks and the duration of analgesia were assessed.
Results: Demographic data and surgical characteristics were comparable in both groups. The onset times for sensory and motor blocks were statistically significantly shorter in group D than group M while the duration of sensory and motor block were statistically significantly longer in group D than those of group M. The duration of analgesia in group D was statistically significant different than in group M.
Conclusion: Dexmedetomidine is more effective than magnesium as an adjuvant to LAs in US guided Brachial plexus block. Dexmedetomidine provide more rapid onset for sensory and motor block and prolong their duration. Also, dexmedetomidine provide duration of analgesia longer than magnesium.