Large versus Small Dose Magnesium Sulfate Infusion in Tetanus

Abstract

Introduction: Evidence based guidelines regarding the use of magnesium sulfate in tetanus is lacking. Hence, our objective was to compare two infusion doses of magnesium sulfate to control the tetanic spasms.
Methods: Data of 14 adult male patients admitted in the intensive care unit were retrieved. Twelve adult ventilated patients received magnesium infusion as an adjunct to diazepam therapy to control tetanic spasms. We retrospectively divided them into two groups for comparison. Group 1 patients (n=7) received a smaller dose (<1 g.h-1) than group 2 (n=5) (1.5 to 2 g.h-1).
Results: The duration of symptoms before arrival to hospital was significantly longer in group 1 than group 2. The Ablett severity grade was II in three patients in group 1 and III in all patients of group 2. In Ablett severity grade III patients, the diazepam dose used was significantly higher in group 1 (n=4) (292±48 mg.d-1) than group 2 (n=3) (106±9 mg.d-1) as magnesium infusion dose was restricted due to hypotension in group 1. Amongst the patients who received MgSO4 for ≥10 days, the requirement of diazepam was significantly reduced in the second week (174.1±59.2 mg/d) than the first week (325.4±105.9 mg.d-1) of infusion in group 2 (n=4) but not in group 1 patients (n=4).
Conclusions: The larger dose of MgSO4 infusion was titrated to control tetanic spasms as an adjunct to diazepam in select group of patients without hypotension. Uncontrolled hypotension, cardiac arrhythmia and renal failure were the factors to limit its infusion dose.
Keywords: MgSO4; magnesium sulphate; tetanus.