Articaine and Dexmedetomidine – supplemented Articaine for arteriovenous fistula creation under ultrasound- guided supraclavicular block

Background: Articaine has emerged as local anesthetic, that produce sensory and motor blockade shorter than bupivacaine and lower in neurotoxicity than lidocaine. Studies have shown that adding dexmedetomidine to local anesthetic produce prolongation of sensory and motor bock duration. Early regain of motor power with adequate analgesia is needed in hemodialysis fistula creation, for early start of physiotherapy. We designed this study to test efficacy of adding dexmedetomidine to Articaine on the duration of sensory and motor block. Methods: After university review board approval, informed written consent to participate in the study was obtained. Patients with chronic renal failure undergoing radiocephalic hemodialysis fistula creation were eligible for enrollment in this double blind, randomized trial. Patients receive either 40 ml of 2% Articaine hydrochloride or 40 ml of Articaine 2% mixed with dexmedetomidine (1 µg/kg). sensory block duration in minutes is assessed by pinprick test and motor block duration in minutes is tested by Bromage scale, both are recorded as a primary outcome. Secondary outcome included onset of sensory and motor block, time for rescue analgesia, hemodynamic changes, over sedation and possible side effect all were recorded. Results: fifty patients were enrolled in the study (25 in Articaine group A and 25 in Articaine dexmedetomidine group AD). Longer sensory block duration was in group AD (230 to 260 min) than in group A (172 to 185min) with p <0.001. Also, motor block duration was significantly longer in group AD 220±110min than in group A 165±45. The duration of effective analgesia was significantly longer in group AD (363 ± 134 min) versus (244 ± 84) min in group A. The onset of block was short and similar between groups. In group AD one patient didn’t ask for analgesia in 24 h postoperative and another patient showed excessive somnolence. There was no other difference in both groups. Conclusion : The addition of dexmedetomidine to Articaine during ultrasound guided supraclavicular block increase duration of sensory and motor block and prolong time of first analgesia required. Although we didn’t detect significant reduction in onset time of block. Further study is needed with larger sample size.