What intravenous medication has the best evidence for preventing hospital admission in an 8-year-old female with acute asthma exacerbation, who has received nebulized albuterol (salbutamol) and oral prednisone, with symptoms of tachypnea, tachycardia, and diffuse expiratory wheezing?

From the Guidelines

For an eight-year-old female with an acute asthma exacerbation in the emergency department, intravenous magnesium sulfate has the best evidence for preventing hospital admission. The recommended dose is typically 25-75 mg/kg (maximum 2 grams) administered as a single dose over 20-30 minutes, as stated in the guidelines 1. Magnesium sulfate works as a bronchodilator by relaxing smooth muscle in the airways through calcium channel blocking effects, which helps reduce bronchospasm and improve airflow. It is particularly effective for moderate to severe exacerbations that have not adequately responded to initial treatments with inhaled beta-agonists (like albuterol) and systemic corticosteroids. This patient's presentation - with continued symptoms despite multiple doses of albuterol and increased controller medication - suggests she may benefit from this intervention.

Some key points to consider when administering magnesium sulfate include:

• Monitoring vital signs, particularly blood pressure, as hypotension can occur with rapid infusion 1
• Being aware of potential side effects, which are generally mild and can include flushing, hypotension, and weakness
• Considering the use of magnesium sulfate in conjunction with other treatments, such as nebulized β-adrenergic agents and corticosteroids, as part of a comprehensive treatment plan for acute asthma exacerbation 1

It is also important to note that other treatments, such as heliox-driven albuterol nebulization, may be considered in certain cases, but the evidence for these treatments is not as strong as it is for magnesium sulfate 1. Additionally, some treatments, such as methylxanthines, antibiotics, aggressive hydration, chest physical therapy, mucolytics, or sedation, are not recommended in the emergency care or hospital setting for acute asthma exacerbation 1.

From the Research

Administration of Medication for Acute Asthma Exacerbation

• The patient's symptoms and history suggest an acute severe asthma exacerbation, which requires aggressive administration of bronchodilators and corticosteroids 2.
• The use of intravenous magnesium sulfate has been shown to be beneficial in patients with severe acute asthma, particularly in those who do not respond to standard therapy 3, 4, 5.

Evidence for Intravenous Magnesium Sulfate

• A systematic review and meta-analysis found that intravenous magnesium sulfate had a significant effect on lung function in some studies, but the evidence for reducing hospital admission rates was limited 5.
• Another study found that intravenous magnesium sulfate improved peak expiratory flow rates and forced expiratory volume in one second in patients with severe acute asthma, and reduced hospital admissions in this subgroup 3.
• The current evidence suggests that intravenous magnesium sulfate may be beneficial in selected cases of severe asthma exacerbations, particularly when used in conjunction with standard bronchodilating agents and corticosteroids 4.

Comparison of Treatment Options

• The evidence suggests that intravenous magnesium sulfate may have a role in preventing the need for hospital admission in patients with acute severe asthma, particularly in those who do not respond to standard therapy 3, 5.
• Other treatment options, such as heliox, general anesthesia, and extra-corporeal carbon dioxide removal, may be considered in extreme cases, but the evidence for these interventions is limited 6.
• The decision to use intravenous magnesium sulfate or other adjunctive therapies should be based on individual patient factors and clinical judgment 2, 4.