Effects of magnesium sulfate on intraoperative body temperature changes in patients undergoing laparoscopic gynaecological surgery under propofol-based total intravenous anaesthesia: a retrospective analysis

The objective of this study was to investigate the effects of intravenous magnesium sulfate (MgSO4) administration on core body temperature (BT) changes in patients undergoing laparoscopic gynaecological surgery under propofol-based total intravenous anaesthesia (TIVA). Data from 120 female patients, aged 20-65, who underwent laparoscopic gynaecological surgery between March 2021 and February 2024, were analysed retrospectively. Patients were divided into Mg (n=49) and non-Mg (n=71) groups. The Mg group received MgSO4 (50 mg/kg in 100-mL isotonic saline over 15 minutes) during induction, followed by a continuous infusion (15 mg/kg/h). Core BT was recorded using tympanic thermometer and oesophageal probes: pre-anaesthesia (BT0), 5 minutes post-induction (BT5), every 15 minutes (BT15 ~ BT105), and at emergence (BT120). All patients were warmed using both a circulating-water mattress and a forced-air warming blanket. BT0 was comparable between groups. BT decreased over time in both groups (p < 0.001). The Mg group had significantly lower BT at BT5 (p = 0.031), BT15 (p = 0.004), BT30 (p = 0.011), and BT45 (p = 0.016). However, the rate of temperature change over time between groups was comparable. The incidence of post-anaesthetic shivering was significantly lower in the Mg group (19.7% vs 6.1%, p = 0.036). During propofol-based TIVA, MgSO4 administration reduced BT at early time points during surgery, while the rate of temperature change over time was not significantly affected by MgSO4 administration. Notably, the incidence of shivering was significantly lower in the Mg group.