Comparison between dexmedetomidine and magnesium sulfate as adjuvants for intravenous regional anesthesia

Background Many adjuvants have been used to improve the quality of intravenous regional anesthesia ( IVRA). The aim of this study was to compare the use of dexmedetomidine with that of magnesium sulfate as an adjuvant for IVRA as regards onset and duration of sensory and motor blocks, quality of anesthesia, intraoperative– postoperative hemodynamic variables, and intraoperative and postoperative pain. Patients and Methods This study was a prospective, randomized, double-blinded trial. Sixty patients scheduled for upper hand or forearm surgery were randomly divided into two groups, comprising 30 patients each. Group D received dexmedetomidine at 0.5 μg/kg diluted with saline to 20 ml in addition to 20 ml of 1% lidocaine to reach a total volume of 40 ml, whereas group M received 5 ml of 20% magnesium sulfate and 15 ml saline added to 20 ml of 1% lidocaine to reach a total volume of 40 ml. Sensory and motor block onset, recovery times, anesthesia quality, and hemodynamic variables were recorded and compared between the two groups. Results No statistically significant difference was observed between dexmedetomidine and magnesium sulfate as regards sensory block onset time and motor block onset time (P = 0.102 and 0.206, respectively) as well as intraoperative analgesic requirements ( P = 0.76). However, dexmedetomidine showed more favorable hemodynamic variables and less tourniquet pain. Conclusion We concluded that dexmedetomidine seems to be superior to magnesium sulfate as an adjuvant to lidocaine in IVRA regarding tourniquet pain and intraoperative and postoperative hemodynamic stability.