A comparative study of brachial plexus block using bupivacaine with midazolam and bupivacaine alone in upper limb surgeries

Background: Adjuncts to local anaesthetics for brachial plexus block may enhance the quality and duration of analgesia. Midazolam, a water-soluble benzodiazepine, is known to produce antinociception and enhance the effect of local anaesthetics when given epidurally or intrathecally. Aim: Study was to assess the effect of Midazolam added to brachial plexus block by supraclavicular approach. Materials and methods: A prospective, randomized, single blinded study was conducted on 100 ASA Grade I or II adult patients undergoing upper limb surgeries under supraclavicular brachial plexus block. Patients were randomly divided into two groups. Patients in Group B (n = 50) Bupivacaine and Group BM (n = 50) Bupivacaine with Midazolam. The onset time and duration of sensory and motor blockade were recorded. Hemodynamic variables (i.e., heart rate, blood pressure and oxygen saturation), sedation scores and rescue analgesic requirements were recorded for 24 hour postoperatively. Results: The onset of sensory and motor block was significantly faster in Group BM compared to Group B (p < 0.05). The duration of sensory and motor block was significantly longer in Group BM compared to Group B (p < 0.05). Rescue analgesic requirements were significantly less in Group BM compared to Group B (p < 0.05). Hemodynamics and sedation scores did not differ between the two groups in the post-operative period. Conclusion: Midazolam (0.05 mg/kg) in combination with 30 mL of Bupivacaine (0.375%) hastened onset of sensory and motor block, and improved postoperative analgesia when used in brachial plexus block, without producing any adverse events.