Investigating the effect of magnesium sulfate administration on postoperative shivering in general surgeries

Objective: Shivering after surgery is one of the common side effects after general anesthesia. Magnesium sulfate is a noncompetitive antagonist receptor and a physiological antagonist of voltage-gated calcium channels that can have analgesic effects. This study aims to investigate the role of magnesium sulfate in reducing postoperative shivering. Materials and methods: This double-blind clinical trial study was conducted on 70 patients undergoing abdominal surgery in (American Society of Anesthesiologists) ASA 1, 2 anesthesia class admitted to Bo Ali Hospital in Tehran in 2018-2019. They were randomly divided into two groups. In the placebo control group, 200 mL of normal saline solution and in the case group, magnesium sulfate 20% with a dose of 50 mg/kg (200 mL) was infused to the patient within 15 minutes after induction of anesthesia. During the surgery and after the surgery, the patient was monitored for tremors for 2 hours. After analyzing the data, it was analyzed by SPSS26 software. Results: The average age of the patients in the intervention group was 42.80 ± 18.00 and in the control group was 48.14 ± 14.88 years. 45.7% of control group patients were female and 54.3% were male. Also, 51.4% of patients in the intervention group were women and 48.6% were men. In the intervention group, the average duration of surgery was 76.28 ± 14.67 minutes and in the control group, this time was 74.14 ± 10.67 minutes. The amount of shivering during recovery in the intervention and control groups was (25.7% and 5.7%) and the shivering 2 hours after the operation in the intervention and control groups was (22.9% and 2.9%). It was found that this amount in the intervention group was significantly lower than in the control group ( P < 0.05). Conclusion: It was found that the administration of intravenous magnesium sulfate before surgery reduces postoperative shivering during recovery and 2 hours after surgery. Duration of operation, age and gender have no significant relationship with the development of this complication.