EFFECT OF MAGNESIUM WITH ROPIVACAINE IN SUPRACLAVICULAR BRACHIAL PLEXUS BLOCK FOR POST-OPERATIVE ANALGESIA: A RANDOMIZED CONTROLLED STUDY

Abstract

Background: Supraclavicular brachial plexus block (SCBPB) is widely used for upper limb surgeries, providing reliable anesthesia and prolonged postoperative analgesia. Ropivacaine, a long-acting amide local anesthetic, offers favorable sensory-motor differentiation with reduced cardiotoxicity. Magnesium sulfate, an N-methyl-D-aspartate (NMDA) receptor antagonist, has been increasingly evaluated as an adjuvant to enhance the quality and duration of regional blocks. Objective: To evaluate the effect of magnesium sulfate as an adjuvant to ropivacaine in ultrasound-guided supraclavicular brachial plexus block on onset, duration of block, and postoperative analgesia. Methods: In this prospective, randomized, double-blinded controlled study, 60 adult patients (ASA I–II) undergoing elective upper limb surgeries were randomly allocated into two groups. Group R (n=30) received 20 mL of 0.5% ropivacaine. Group RM (n=30) received 20 mL of 0.5% ropivacaine with 150 mg magnesium sulfate. Sensory and motor block onset times, duration of blocks, time to first rescue analgesia, Visual Analog Scale (VAS) scores, and hemodynamic parameters were recorded and analyzed. Results: The addition of magnesium significantly prolonged the duration of sensory block (812 ± 64 min vs 620 ± 58 min; p<0.001), motor block (748 ± 70 min vs 580 ± 62 min; p<0.001), and duration of analgesia (910 ± 85 min vs 650 ± 72 min; p<0.001). Time to first rescue analgesia was significantly delayed in Group RM (p<0.001). Onset of sensory and motor block was faster in Group RM (p<0.05). Hemodynamic parameters remained stable and comparable between groups. No significant adverse effects were observed. Conclusion: Magnesium sulfate (150 mg) added to ropivacaine in supraclavicular brachial plexus block significantly extends postoperative pain relief and the duration of the block without raising complications. Magnesium is a safe and effective addition for improving regional anesthesia results in upper limb surgeries.