Efficacy of intravenous regional anesthesia with dexmedetomidine: local addition versus systemic infusion

Abstract

Background Intravenous regional anesthesia (IVRA) is a type of regional anesthesia that is administered using a pneumatic tourniquet isolating the limb from the systemic circulation. IVRA has been limited by tourniquet pain and the inability to provide postoperative analgesia. Thus, to improve the quality of IVRA and avoid these problems, additives are added to local anesthetics. We designed this study to evaluate the efficacy of IVRA by using dexmedetomidine locally versus an intravenous systemic infusion. Materials and methods Overall, 60 ASA I-II patients of either sex, 18-65 years old, scheduled for hand or distal forearm surgeries were studied. Patients were divided randomly into three groups (20 patients each): group L received 3 mg/kg lignocaine completed to 40 ml normal saline (NS), group LD1 received 0.5 μg/kg dexmedetomidine added to 3 mg/kg lignocaine completed to 40 ml NS, and group LD2 received 3 mg/kg lignocaine completed to 40 ml NS plus an intravenous infusion of 1 μg/kg dexmedetomidine over 10 min 15 min before IVRA, followed by maintenance of dexmedetomidine infusion at the rate of 0.02-0.06 μg/kg/min. Onset and recovery times of sensory and motor blocks, tourniquet pain, rescue analgesia, and visual analogue scale postoperatively were monitored. Results Onset and recovery times of sensory and motor blocks were shorter in group LD1 compared with the other two groups. Time of tourniquet pain was found to be prolonged in groups LD1 and LD2 compared with group L. The use of rescue fentanyl and tramadol in the first 24 h was increased in group L versus both the other two groups. Conclusion Local addition of dexmedetomidine to IVRA produced shorter onset and slower recovery of sensory and motor blocks compared with systemic infusion of dexmedetomidine. The durations of postoperative analgesia and rescue analgesia were comparable between both groups using dexmedetomidine either locally or systemically.