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 [MgSO4] 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 MgSO4 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 MgSO4 infusion [M], and control [C]. Group T (no. = 45) received 50 mg MgSO4 added to heavy bupivacaine 0.5% intrathecally, while group M (no. = 45) received IV MgSO4 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 MgSO4 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.