Dexmedetomidine Versus Dexamethasone as an Adjuvant in Supraclavicular Brachial Plexus Block: A Comparative Study

Abstract

Background: Supraclavicular brachial plexus block is widely used for upper limb surgeries because it provides excellent intraoperative anesthesia and prolonged postoperative analgesia. Various adjuvants have been added to local anesthetics to improve block characteristics and prolong analgesic duration. Dexmedetomidine and dexamethasone are among the most commonly used adjuvants in peripheral nerve blocks.
Aim: To compare dexmedetomidine and dexamethasone as adjuvants to bupivacaine in supraclavicular brachial plexus block with respect to onset and duration of sensory and motor blockade, duration of postoperative analgesia, and adverse effects.
Materials and Methods: A prospective randomized comparative study was conducted in the Department of Anaesthesiology at SCB Medical College, Cuttack and SJMCH, Puri over a period of 11 months. A total of 110 patients undergoing elective upper limb surgeries under supraclavicular brachial plexus block were included. Patients were randomly allocated into two groups: Group DEX receiving dexmedetomidine 1 μg/kg with bupivacaine and Group DEXA receiving dexamethasone 8 mg with bupivacaine. Sensory block onset, motor block onset, duration of analgesia, hemodynamic parameters, and complications were evaluated. Statistical analysis was performed using IBM SPSS version 26.0. Independent t-test, Chi-square test, repeated measures ANOVA, and Kaplan–Meier survival analysis were applied. A p-value <0.05 was considered statistically significant.
Results: The onset of sensory block was significantly shorter in Group DEX compared to Group DEXA (8.42 ± 1.64 min vs 10.86 ± 1.88 min; p<0.001). Duration of postoperative analgesia was significantly prolonged in Group DEXA (846.5 ± 92.6 min) compared to Group DEX (768.2 ± 84.3 min; p<0.001). Bradycardia was more common in Group DEX (p=0.048).
Conclusion: Dexmedetomidine provides faster onset of blockade, whereas dexamethasone significantly prolongs postoperative analgesia and duration of blockade when used as adjuvants in supraclavicular brachial plexus block.