Feasibility of Short-Term Infusion of Magnesium Sulfate in Pediatric Patients With Status Asthmaticus

Abstract

OBJECTIVE This report describes the feasibility of high-dose magnesium sulfate infusion in pediatric patients with status asthmaticus. METHODS Retrospective chart review over a 3-year period of all patients younger than 18 years of age with status asthmaticus who underwent a high-dose magnesium sulfate infusion for 4 hours. All patients were breathing spontaneously but were refractory to conventional therapy. The magnesium sulfate infusion regimen was 50 mg/kg (for patients weighing .30 kg) or 75 mg/kg (for those weighing 30 kg) over a period of 30 to 45 minutes, followed by a continuous infusion of 40 mg/kg/hr for 4 hours. Information regarding vital and clinical respiratory signs, serum magnesium (SrMg), ionized magnesium (iMg), electrocardiograms, and cardiac troponin levels were retrieved. We analyzed the relationship between SrMg and iMg by using linear regression analysis. RESULTS Nineteen patients were included. At the end of the infusion, SrMg levels were 4.4 6 0.8 mg/ dL, and iMg levels were 0.95 6 0.2 mmol/L. SrMg levels only moderately predicted iMg (r 2 ¼ 0.541). There were no reports of hypotension, respiratory failure, neurological problems, or nausea. Discomfort at the site of infusion was reported in three cases. Troponin levels (n ¼ 12) and electrocardiograms (n ¼ 12), when available, were noted at the end of the infusion and were normal in all patients p¼0.01. CONCLUSIONS In this case series, short-term high-dose administration of magnesium sulfate in the context of status asthmaticus was feasible, and we did not observe clinical complications with its use. Total SrMg was inadequate to reflect the active form of magnesium, iMg. The dose used achieved theoretical therapeutic levels of iMg.INDEX TERMS asthma, feasibility, infusion, magnesium sulfate, status asthmaticus J Pediatr Pharmacol Ther 2012;17(2):150-154

High-Dose Magnesium Sulfate Infusion for Severe Asthma in the Emergency Department

“…Ipratropium bromide was not available in Paraguay during our study, and we cannot speculate about how its coadministration would have altered our findings. Although safety concerns were not a primary endpoint in this study, HDMI was not associated with clinically significant safety concerns, consistent with previous reports (9,10). Furthermore, this experience may not be generalizable to a population suffering from obesity as a comorbidity, a situation that may require adjustment of HDMI dosing.…”

“…Studies involving young children suggest a superior effect than aminophylline and terbutaline but not to salbutamol and that an early administration is associated with fewer patients requiring mechanical ventilatory support (invasive or noninvasive) (23)(24)(25). However, several authors suggest a need of higher dose regimens (9,20,21,23), and multicenter studies have failed to show a consistent decrease in hospital admissions or early discharge (4,21,22). We found superiority of HDMI over MgSO 4 bolus in inducing a shorter LOS when used as an early ED adjunctive therapy in older children and adolescents with severe noninfectious asthma.…”

“…Of note, the studied group did not suffer from obesity. HDMI pharmacokinetic have shown magnesium serum levels associated with smooth muscle relaxation but a need of adjustment in patients with obesity (9,10,(26)(27)(28)(29).…”

“…Therefore, the maximum serum level during therapy depends more on the rate of infusion and not on the total dose or duration of the infusion. We have previously determined the feasibility and safety of a high-dose, prolonged magnesium infusion (HDMI) in the PICU for status asthmaticus, producing sustained levels of IoMg associated with smooth muscle relaxation (9)(10)(11).…”

High-Dose Magnesium Infusions for Acute Severe Asthma in Children

“…The study builds upon the authors' previous work examining the feasibility and safety of high-dose magnesium infusions in the pediatric ICU (11). The investigators theorized that because repeated doses of magnesium are sometimes used in children with status asthmaticus, a higher dose, short-term infusion may be more effective than a single bolus given magnesium's rapid elimination by the kidneys.…”