Comparative study of dexmedetomidine and clonidine as adjuvants to levobupivacaine in ultrasound-guided supraclavicular brachial plexus block in upper limb surgeries in a tertiary care center in Kerala

Background: Peripheral nerve blockade provides effective analgesia with fewer side effects than general anesthesia. Adjuvants, such as clonidine and dexmedetomidine, enhance block quality and duration, with dexmedetomidine offering superior α2 receptor selectivity. Aims and Objectives: This study aimed to compare the efficacies of clonidine and dexmedetomidine when added to levobupivacaine as an adjuvant in supraclavicular brachial plexus blocks. Materials and Methods: This prospective study included 50 patients who underwent elective upper limb procedures at Dr. SMCSI Medical College Hospital between 2021 and 2022. A total of 50 patients were randomized into two groups: Group A received 25 mL of 0.5% levobupivacaine with clonidine (0.5 mcg/kg), and Group B received 25 mL of 0.5% levobupivacaine with dexmedetomidine (0.5 mcg/kg). The onset and duration of the sensory and motor blocks were assessed. The hemodynamic parameters were monitored at regular intervals. Post-operative pain was evaluated using the Visual Analog Scale (VAS), and rescue analgesia was administered when the VAS score was ≥5. Results: Group B demonstrated significantly faster onset of sensory (8.88±0.833 vs. 11.04±1.098 min, P<0.001) and motor block (11.36±0.952 vs. 13.48±1.122 min, P<0.001), as well as longer durations of sensory (9.68±0.627 vs. 8.10±0.677 h, P<0.001) and motor block (8.84±0.534 vs. 7.26±0.561 h, P<0.001) compared to Group A. Time to rescue analgesia was also longer in Group B (11.28±1.09 vs. 9.08±0.731 h, P<0.001). Pulse rate, systolic and diastolic blood pressure, and oxygen saturation were not significantly different between the groups (P>0.05). Conclusion: Dexmedetomidine prolongs the duration of sensory and motor block and enhances the quality of block compared with clonidine when used as an adjuvant to levobupivacaine in peripheral nerve blocks.