The Effects of Magnesium Sulfate with Lidocaine for Infraclavicular Brachial Plexus Block for Upper Extremity Surgeries

Background An addition of analgesic to anesthetic agents is likely to increase the effects of anesthesia and reduce associated adverse outcomes. Several adjuvants are studied in this regard. The aim of this study is to investigate the effects of adding a magnesium adjunct to lidocaine for the induction of infraclavicular block. Methods Patients referred to Shohada Ashayer Hospital, Khorramabad, for wrist and hand surgery were enrolled in this study. The intervention/case group included patients who received 18mL lidocaine (2%)+2mL magnesium sulfate (50%), 10mL normal saline; control group: 18mL lidocaine (2%)+12mL of normal saline. After the induction of ultrasound-guided infraclavicular block, parameters such as duration of reach with respect to complete sensory and motor block, hemodynamic parameters (hypotension and bradycardia), and postoperative pain, using visual analogue scale criteria, were measured. The obtained data were analyzed using a Bayesian path analysis model. Results A total of 30 patients were included in each group. In the case group, sensory and motor block was achieved for 12.1364.96 and 13 +/- 3.589minutes more than those in the control group. The duration of sedation and immobilization was 2.57 +/- 0.764minute and 4.66 +/- 0.909minutes lengthier in the case group. Regarding the hemodynamic parameters, blood pressure was 0.217 +/- 5.031 and 1.59 +/- 5.14 units lower in the case group, immediately following the block and the surgery. Similarly, heart rate was 0.776 +/- 4.548 and 0.39 +/- 3.987 units higher in the case group, after 30minutes and 2hours of the procedure. A decrease in the pain was seen at 8, 10, and 12hours after the surgery, as compared with the control group. An addition of magnesium to lidocaine for infraclavicular block resulted in a significantly longer sedation and immobilization period and decreased postoperative pain at 12hours. Conclusion Heart rate and blood pressure did not decrease significantly in the case group. It can be concluded that addition of magnesium sulfate to lidocaine can produce better anesthetic and analgesic outcomes with low-to-no adverse effects.