Magnesium sulfate intravenous infusion versus intrathecal injection for prevention of post-spinal shivering during lower limb fracture surgery: a randomized controlled study

Abstract

Abstract Background Shivering is a prevalent adverse event after spinal anesthesia, often disturbing to medical staff and hazardous to patients. Intravenous magnesium sulfate [MgSO 4 ] has been proven to be effective in prevention of post-spinal shivering. However, the risk of intravenous route to develop hypermagnesemia in certain patients encouraged us to do this study in order to investigate the effectiveness of intrathecal MgSO 4 as an alternative to the intravenous route in prevention of post-spinal shivering. The enrolled 135 patients were allocated to 3 groups, 45 patients each, groups: intrathecal [T], IV MgSO 4 infusion [M], and control [C]. Group T (no. = 45) received 50 mg MgSO 4 added to heavy bupivacaine 0.5% intrathecally, while group M (no. = 45) received IV MgSO 4 as 50 mg/kg in 100 cc saline within 20 min as a loading dose then infused as 2 mg/kg/h after performing spinal anesthesia. The vital signs, duration and shivering grades, temperature, and adverse effects were recorded. Results T and M groups showed a significant difference from control as regard the incidence of shivering with 40%, 26.7%, and 64.4% for T, M, and C groups, respectively, patients needed rescue pethidine were 17.7%, 11.1%, and 60% for group T, M, and C, respectively, and shivering duration (min) was 24.86 ± 7.411, 20.47 ± 6.61, and 45 ± 36.2 for groups T, M, and C, respectively with a statistically insignificant difference between group T and M as regards these parameters. Conclusions Intrathecal MgSO 4 has the potentiality to be used as an alternative to IV route regarding prevention of post-spinal shivering. This makes advantage for intrathecal magnesium use in patients at risk for magnesium toxicity.