Comparative study of supraclavicular brachial plexus block with or without dexamethasone

Background: Local anesthetics with various adjuvants are used to increase the duration of postoperative analgesia in supraclavicular brachial plexus block. Perineural injection of steroid is known to influence postoperative analgesia.Materials and Methods: A total of fifty patients of the American Society of Anaesthesiologist Grade I–II undergoing various upper limb surgeries under supraclavicular brachial plexus block were randomly divided into two groups. In Group C, patients received 32 ml of mixture of 1.5% lignocaine–adrenaline 10 ml, 0.5% bupivacaine 20 ml and normal saline 2 ml, whereas in Group D, patients received the same amount of local anesthetics with dexamethasone 2 ml (8 mg). Sensory and motor block were recorded at the regular intervals. Postoperative analgesia was assessed using visual analog scale (VAS) score. Statistical analysis was performed using Student's unpaired t-test.Results: The mean onset time of sensory and motor block was 3.24 ± 1.09 min and 6.2 ± 1.44 min in Group D and 4.24 ± 1.42 min and 7.52 ± 1.50 min in Group C, respectively. There was markedly prolonged duration of analgesia in Group D (12–16 h) compared to Group C (4–5 h). The mean VAS score was 4.16 ± 1.39 at the end of 6 h in Group C, whereas it was 0 (zero) in Group D at the same time. The difference was statistically significant (P < 0.05).Conclusion: Addition of dexamethasone as an adjuvant to local anesthetics in brachial plexus block provides in significantly early-onset and markedly prolonged duration of analgesia without hemodynamic disturbances.