Background and aims: The primary aim of this study was to evaluate the effect of addition of dexmedetomidine on the duration of analgesia in patients undergoing upper limb surgeries under supraclavicular brachial plexus block.
Material and methods: Sixty patients of American Society of Anesthesiologists physical status I/II/III undergoing elective upper limb surgeries under supraclavicular brachial plexus block using nerve stimulator were randomized into two groups. Group A (n = 30) received 30 mL 0.5% ropivacaine and 1 mL normal saline, and Group B (n = 30) received 30 mL 0.5% ropivacaine and 1 μg/kg of dexmedetomidine. The primary outcome was the duration of analgesia. Secondary outcomes included time to onset and duration of sensory/motor blockade.
Statistical analysis: Results on continuous measurements are presented as mean ± standard deviation and compared using Student's unpaired t-test. Results on categorical measurements are presented in number (%) and compared using Chi-square test.
Results: Onset of sensory and motor block in Group A (13.0 ± 4.1 and 23.5 ± 5.6 min) was slower than those in Group B (9.5 ± 5.8 and 15.6 ± 6.3 min; P = 0.009 for sensory and P < 0.001 for the motor block). Duration of sensory and motor block in Group A (400.8 ± 86.6 and 346.9 ± 76.9 min) was shorter than those in Group B (630.6 ± 208.2 and 545.9 ± 224.0 min; (P < 0.001). The duration of analgesia in Group A (411.0 ± 91.2 min) was shorter than that in Group B (805.7 ± 205.9 min; P < 0.001). The incidence of bradycardia and hypotension was higher in Group B than in Group A (P < 0.001).
Conclusion: Perineural dexmedetomidine with ropivacaine provides prolonged postoperative analgesia, hastens the onset of sensory and motor block and prolongs the duration of the supraclavicular brachial plexus block.
Keywords: Brachial plexus block; dexmedetomidine; regional anesthesia; ropivacaine.