Dexmedetomidine and Magnesium Sulfate as Adjuvant to 0.5% Ropivacaine in Supraclavicular Brachial Plexus Block: A Comparative Evaluation

BACKGROUND: Dexmedetomidine and magnesium sulfate (MgSO(4)) as an adjuvant to local anesthetics and ultrasound guidance improves the quality of peripheral nerve block. AIM: We aim to compare the efficacy of dexmedetomidine and MgSO(4) as an adjuvant to ropivacaine in supraclavicular brachial plexus block. METHODOLOGY: Sixty patients undergoing upper extremity orthopedic surgery were randomly allocated into three groups of 20 each. Group A received 29 mL of 0.5% ropivacaine plus 1 mL of normal saline, Group B received 29 mL of 0.5% ropivacaine plus 1 mL dexmedetomidine (100 μg), and Group C received 29 mL of 0.5% ropivacaine plus 1 mL MgSO(4) (250 mg). Onset and duration of sensory and motor block, duration of analgesia, quality of anesthesia, total 24 h analgesic consumption, sedation, and complications were recorded. STATISTICAL ANALYSIS: Software SPSS-16 was used for statistical analysis. RESULTS: The onset of sensory block and motor block was fastest for Group B, followed by Group C and slowest in Group A. The duration of sensory block and motor block was maximum for Group B, followed by Group C and minimum for Group A. The duration of analgesia was maximum for Group B, followed by Group C and minimum for Group A. Analgesic consumption was minimum for Group B. Quality of anesthesia was better in Group B than other groups. The visual analog scale was higher in Group A than other groups. Group B reported higher sedation score. CONCLUSION: Dexmedetomidine provides earlier onset of sensory and motor block as well as prolonged duration of sensory and motor blocks and duration of analgesia is longer and postoperative rescue analgesia is less as compared to patients receiving MgSO(4). The incidence of hypotension and bradycardia and sedation score was higher with dexmedetomidine.