Acute magnesium toxicity in an obstetric patient undergoing general anaesthesia for caesarean delivery

Magnesium is commonly used in the prevention of eclampsia. Reports of acute toxicity are rare and we are not aware of detailed management algorithms. We present a case of acute magnesium toxicity presenting as ventilatory impairment and failure to rouse adequately from general anaesthesia. The patient was managed with controlled ventilation, further sedation, intravenous calcium gluconate, forced diuresis and dextrose-insulin infusion. We present a guideline for the management of life-threatening magnesium toxicity and discuss measures that may prevent future similar occurrences.