From the Guidelines
The recommended dose of magnesium sulfate for pediatric asthma management is 25-75 mg/kg (maximum 2 grams) administered as a single intravenous infusion over 20 minutes. This dosing is typically reserved for children with moderate to severe asthma exacerbations who have not adequately responded to initial bronchodilator therapy. According to the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1, magnesium sulfate can moderately improve pulmonary function in patients with asthma when combined with nebulized β-adrenergic agents and corticosteroids. The mechanism of action involves relaxation of bronchial smooth muscle independent of serum magnesium level, with only minor side effects such as flushing and light-headedness.
Key considerations for administration include:
- Monitoring vital signs, oxygen saturation, and cardiac rhythm during infusion
- Preparing the medication in appropriate dilution, typically in normal saline
- Infusing the medication slowly to minimize adverse effects
- Administering in a monitored setting due to potential side effects including hypotension, flushing, and respiratory depression
While not first-line therapy, magnesium sulfate can be an effective adjunct treatment for children with significant bronchospasm who remain in respiratory distress despite standard treatments like albuterol, ipratropium, and systemic corticosteroids. The use of magnesium sulfate is supported by a Cochrane meta-analysis of 7 studies, which concluded that IV magnesium sulfate improves pulmonary function and reduces hospital admissions, particularly for patients with the most severe exacerbations of asthma 1.
From the Research
Magnesium Sulfate Dosing for Pediatric Asthma Management
- The recommended dose of magnesium sulfate for pediatric asthma management is not uniformly established, but various studies provide insights into its usage:
- A study from 1996 2 used a magnesium sulfate infusion of 25 mg/kg (maximum, 2 gm) for 20 minutes in pediatric patients with moderate to severe asthma exacerbations.
- Another study from 2021 3 used a continuous infusion of magnesium sulfate at a dose of 50 mg/kg/h in 4 h for children with severe acute asthma.
- The efficacy of intravenous magnesium sulfate in pediatric asthma management has been demonstrated in several studies:
- A systematic review from 2014 4 found that intravenous magnesium sulfate therapy helps in achieving earlier improvement in clinical signs and symptoms of asthma and significantly reduces hospital admission in children with acute severe asthma.
- A study from 1996 2 showed that intravenous magnesium sulfate infusion improved short-term pulmonary function in children with moderate to severe asthma without significant alteration in blood pressure.
- The use of inhaled magnesium sulfate in pediatric asthma management is less clear:
- A study from 2010 5 found that inhaled magnesium sulfate improved lung function and oxygen saturation and reduced hospital admission in adults with severe asthma crisis, but its use in pediatric patients requires further investigation.
- Overall, the available evidence suggests that intravenous magnesium sulfate may be a useful adjunctive therapy in the management of severe acute asthma in children, but more research is needed to establish its optimal dosing and efficacy in pediatric patients 4, 2, 3, 6.