Atracurium mixed with magnesium sulfate versus atracurium alone as adjuvant to lidocaine in intravenous regional anesthesia

Background
Intravenous regional anesthesia (IVRA) is considered one of the regional techniques used for surgical anesthesia in the upper extremity without the need for general anesthesia. Local anesthetics are used commonly in this method; also, adjuvant drugs are used to increase the quality of the block.
Aims and objectives
This study evaluated the effect of adding either atracurium alone or atracurium plus magnesium added to lidocaine for IVRA on intraoperative and postoperative analgesia, onset and recovery times of sensory and motor blockades, and tourniquet pain.
Patients and methods
Seventy-five patients scheduled for hand or forearm surgery were allocated randomly into three groups. Group A received 3 mg/kg of lidocaine 2%. Group B received 3 mg/kg of lidocaine 2%+2 mg atracurium. Group C received 3 mg/kg of lidocaine 2%+2 mg atracurium mixed with 10 mg/kg magnesium sulfate. All preparations were diluted with saline to a total volume of 40 ml. Postoperative analgesia during the first 24 h, the onset and the recovery times of sensory and motor block, first analgesic request, the tourniquet pain, side effects of the study drugs, and the quality of anesthesia were assessed.
Results
The time to first analgesia requirement was significantly longer in B group than A group and the longest time was recorded in group C. The onset times of sensory and motor blockades were shorter in group B and group C than in group A. Complete sensory and motor blockade occurred in group B and group C earlier than group A. Onset of recovery of sensory and motor blockades postoperatively were longer in group B and group C than in group A.
Conclusion
Adding magnesium sulfate and atracurium combination to lidocaine in IVRA prolonged the time to the first postoperative analgesia requirement and shortened the sensory and motor block onset times.