Comparative Evaluation of Adjuncts , Clonidine versus Dexmedetomidine to Lignocaine In Intravenous Regional Anesthesia ( IVRA ) For Upper Limb Orthopedic Surgeries

Background: Intravenous Regional Anesthesia (IVRA) provides reliable and rapid anesthesia of the extremities distal to the tourniquet, but tourniquet pain and absence of post-operative analgesia are major disadvantages. Hence the present study, to compare the α2 agonists, clonidine and Dexmedetomidine as adjuncts to IVRA with respect to block characteristics, tourniquet pain and post-operative analgesia was conducted as these (α2 agonists) are known to potentiate peripheral nerve blocks. Patients and Methods: In this prospective randomized, double-blind study, 60 patients of ASA-I and ASA-II, undergoing upper limb orthopedic surgeries were randomly allocated into two groups, each of 30 patients. Group-I received Clonidine1μg/kg and Group-II received Dexmedetomidine 1μg/kg dissolved in 40ml of 0.5% of preservative-free lignocaine. Statistical analysis of data i.e. demographic, hemodynamic and block characteristics was done by using various analytical tests and pvalue of< 0.005 was considered statistically significant. Results: Intra-operative Visual-Analogue Scale (VAS) at 5min, 10 min, 15min, 20min and 40min and postoperative VAS at 2hrs and 4hrs and 12hrs were significantly higher in group-I (clonidine group). Sensorimotor block onset was significantly faster and recovery delayed with group-II (Dexmedetomidine group) as compared to group-I (clonidine group). Duration of analgesia was significantly longer with group-II (Dexmedetomidine group). Demographic data, hemodynamic parameters, fentanyl consumption and sedation were comparable among the two groups. Conclusion: Dexmedetomidine significantly facilitates onset, prolongs recovery of sensory and motor block as well as duration of post-operative analgesia as compared to clonidine. Patient satisfaction was better in Dexmedetomidine group; however, patients of both groups have comparable intra-operative fentanyl requirement and both decrease tourniquet pain satisfactorily.