Intravenous magnesium sulphate infusion as first-line therapy in the control of spasms and muscular rigidity in childhood tetanus.

Background : Reports suggest that, in tetanus, magnesium sulphate (MgSO4 ) alone may control muscle spasms, thereby avoiding sedation and mechanical ventilation. Aim : To study the efficacy and safety of intravenous MgSO4 in controlling spasms and rigidity in children with tetanus. Methods : All children with tetanus consecutively admitted over a 2-year period in a tertiary-care teaching hospital were recruited. In addition to human tetanus immunoglobulin and parenteral metronidazole, patients received MgSO4 100 mg/kg intravenously followed by infusion at 40 mg/kg/hr. The infusion rate was increased by 5 mg/kg/hr every 6 h until cessation of spasms or abolition of the patellar tendon reflex. Efficacy was determined by control of spasms. Time to commencement of feeds, frequency of autonomic instability, the need for ventilatory support, duration of hospitalisation and mortality were also recorded. Results : Twenty-seven children with tetanus aged between 18 months and 10 years were recruited. A contaminated wound was the most common portal of entry of tetanus spores. The incidences of severity were: grade I, 3; grade II, 7; grades IIIa and b, 17. Rigidity and spasms were controlled by magnesium therapy alone in 14 patients. Additional sedation was required for 13 patients (grade II, 1; grade III, 12). Feeding could be commenced early in five patients. Mechanical ventilation was required in eight patients. The mean (SD) duration of hospitalisation was 26.5 (12.0) days. Five patients died (18.5%). Asymptomatic hypocalcaemia was a universal finding and was treated with calcium supplements. Conclusion : MgSO4 alone is effective in mild-to-moderate tetanus but not when it is severe.