From the Guidelines
Magnesium sulfate is the recommended adjunctive therapy for severe asthma exacerbations in children not responding to standard treatments including oxygen, short-acting beta-agonists (SABAs), ipratropium bromide, and systemic corticosteroids. The typical dose is 25-75 mg/kg (maximum 2 grams) administered as an intravenous infusion over 20 minutes, as stated in the guidelines for managing asthma exacerbations 1. This medication works as a bronchodilator by relaxing smooth muscle in the airways through calcium channel blocking effects, and it also has anti-inflammatory properties that help reduce airway inflammation.
Key considerations for the use of magnesium sulfate in this context include:
- Administration in a monitored setting where vital signs and oxygen saturation can be observed, due to potential side effects such as hypotension and respiratory depression.
- The importance of early consultation with pediatric critical care specialists if the child continues to deteriorate despite magnesium therapy, as mechanical ventilation may become necessary.
- Alternative considerations if magnesium sulfate is ineffective, such as intravenous terbutaline, aminophylline, or heliox therapy, though these are typically reserved for critical cases in intensive care settings.
It's also worth noting that heliox-driven albuterol nebulization can be considered as an adjunctive therapy in severe asthma exacerbations, as mentioned in the guidelines 1. However, the evidence for heliox is complicated by the small number of subjects in most trials and methodological differences between studies.
Overall, the management of severe asthma exacerbations in children requires prompt and effective treatment, and magnesium sulfate is a recommended adjunctive therapy for those not responding to initial treatments, based on the guidelines from the National Asthma Education and Prevention Program Expert Panel Report 3 1.
From the Research
Effective Adjunctive Therapies for Severe Asthma Exacerbation
In a child not responding to oxygen, short-acting beta-agonists (SABAs), ipratropium, and corticosteroids, several adjunctive therapies have been shown to be effective:
- Intravenous magnesium sulfate has been found to reduce hospital length of stay and the risk of hospital admission in children with acute exacerbations of asthma 2.
- The addition of inhaled anticholinergic agents to inhaled beta2-agonists has been shown to reduce the risk of hospital admission 2.
- Inhaled heliox may also reduce the risk of hospital admission, although the certainty of evidence is low 2.
- Nebulized magnesium is not recommended for routine use in acute asthma, but intravenous magnesium sulfate may be considered in selected cases, particularly in severe exacerbations 3.
Considerations for Treatment
When considering adjunctive therapies for severe asthma exacerbation in children, it is essential to:
- Assess the severity of the exacerbation and the child's response to initial treatment 4.
- Consider the potential benefits and harms of each adjunctive therapy, as well as the certainty of evidence supporting its use 2.
- Develop an individualized treatment plan that takes into account the child's specific needs and medical history 5.
Gaps in Current Evidence
There are limited data on the comparative effectiveness of different adjunctive therapies for severe asthma exacerbation in children, and further research is needed to determine which patients are most likely to benefit from these therapies 2. Additionally, there is a need for the development of an internationally agreed core outcome set for future trials in acute severe asthma exacerbations 2.