Safety of prolonged magnesium sulfate infusions during treatment for severe pediatric status asthmaticus

Magnesium sulfate (Mg) is one of several "second-tier" therapies for treating severe status asthmaticus. Pediatric reports primarily describe bolus use with limited data regarding prolonged infusions. We sought to describe the safety of prolonged Mg infusions during therapy of status asthmaticus in critically ill children.

Single center, retrospective study.

Thirty-four-bed tertiary level medical/surgical/cardiac surgical pediatric intensive care unit.

Pediatric patients 2 to 18 years of age admitted with status asthmaticus receiving Mg infusion for more than 24 hours.

None.

A total of 154 children received Mg infusions for a median of 53.4 hours (interquartile range = 36.6-74.8). The most common adverse event (AE) was hypotension (48.1%), almost exclusively diastolic (94%), and was mostly limited to 1 blood pressure measurement (78%). 2.9% of events required intervention (fluids, decrease Mg infusion). Other AEs included nausea/emesis (22.7%), transient weakness (14.9%), and flushing (6.5%). Five patients experienced serious AEs including hypotonia (n = 1), escalation to continuous or bilevel positive airway pressure (n = 3), and sedation (n = 1), all attributed to progression of underlying medical disease. No patient required endotracheal intubation. Supratherapeutic levels (>6 mg/dL) were uncommon (2%) and were not more likely to be associated with AEs. Most (81%) patients were therapeutic by the 2nd Mg level check.

Prolonged Mg infusions were well tolerated in pediatric status asthmaticus patients. While diastolic hypotension was not uncommon, rarely were interventions deemed necessary. No serious AEs were attributed to Mg. Toxicity was uncommon suggesting that Mg levels could potentially be checked less frequently than historically reported.