What is the management of acute asthma exacerbation in inpatients?

From the Guidelines

Inpatient management of asthma exacerbations should prioritize supplemental oxygen, short-acting beta-agonists, and systemic corticosteroids to reduce morbidity, mortality, and improve quality of life. The most recent and highest quality study 1 recommends starting with supplemental oxygen to maintain saturation ≥92%, and administering short-acting beta-agonists (albuterol 2.5-5 mg nebulized every 20 minutes for 1 hour, then every 1-4 hours as needed) plus ipratropium bromide (0.5 mg nebulized every 20 minutes for 1 hour, then every 4-6 hours). Systemic corticosteroids should be given early (prednisone 40-60 mg orally daily or methylprednisolone 40-80 mg IV daily, divided into 1-2 doses) and continued for 5-7 days.

Key considerations in the management of asthma exacerbations include:

• Monitoring patients with serial assessments of symptoms, lung function (peak flow or spirometry), oxygen saturation, and vital signs
• Administering intravenous fluids for dehydration, and antibiotics only if bacterial infection is suspected
• Considering continuous albuterol nebulization (10-15 mg/hour) and magnesium sulfate (2 grams IV over 20 minutes) for severe exacerbations
• Ensuring symptoms are controlled, lung function is at least 70% of personal best, and patients understand their medication regimen and follow-up plan before discharge

The use of heliox-driven albuterol nebulization and noninvasive ventilation may be considered in specific cases, but the evidence is limited and more research is needed 1. Consultation with or comanagement by a physician expert in ventilator management is essential for patients requiring mechanical ventilation. The recommended ventilator strategy is "permissive hypercapnia" or "controlled hypoventilation" to provide adequate oxygenation while minimizing airway pressures and the possibility of barotrauma.

Overall, the goal of inpatient management of asthma exacerbations is to reduce airway inflammation, reverse bronchoconstriction, and improve airflow, which collectively help resolve the exacerbation and prevent relapse, as supported by the National Asthma Education and Prevention Program Expert Panel report 2 and other guidelines 3.

From the Research

Asthma Exacerbation Inpatient Management

• Asthma exacerbation is defined as a progressive increase in symptoms of shortness of breath, cough, or wheezing sufficient to require a change in therapy 4
• Therapy should be initiated after ruling out diagnoses that mimic an asthma exacerbation, and short-acting β2 agonists and short-acting muscarinic antagonists are effective as bronchodilators for asthma in the acute setting 4
• Systemic corticosteroids to reduce airway inflammation continue to be the mainstay therapy for asthma exacerbations, and, unless there is a contraindication, the oral route is favored 4

Medications and Treatments

• Nebulized magnesium should not be routinely used in acute asthma, but the evidence favors the use of intravenous magnesium sulfate in selected cases, particularly in severe exacerbations 4
• Methylxanthines have a minimum role as therapy for asthma exacerbations but may be considered in refractory cases of status asthmaticus with careful monitoring of toxicity 4
• Current guidelines recommend the use of helium-oxygen mixtures in patients who do not respond to standard therapies or those with severe disease 4
• The addition of a short-acting muscarinic antagonist and magnesium sulfate infusion has been associated with fewer hospitalizations 5

Practice Patterns and Outcomes

• The use of adjunct interventions for patients with severe asthma exacerbations varies widely across U.S. hospitals, but hospitals generally fall into two clusters differentiated primarily by the use of invasive or noninvasive mechanical ventilation 6
• The cluster favoring noninvasive mechanical ventilation was associated with improved outcomes, including more hospital-free days and reduced in-hospital mortality 6
• Patients needing admission to the hospital require continued monitoring and systemic therapy similar to treatments used in the emergency department, with improvement in symptoms and forced expiratory volume in one second or peak expiratory flow to 60% to 80% of predicted values helping to determine appropriateness for discharge 5

Specific Patient Populations

• In children hospitalized because of an acute asthma exacerbation, the addition of nebulized ipratropium bromide to nebulized beta(2)-agonist and corticosteroid therapy confers no extra benefit 7
• In patients with acute asthma, the use of combination nebulized anticholinergic and adrenergic bronchodilators vs nebulized adrenergic bronchodilator alone showed a trend toward greater bronchodilation in the combination group, but this did not reach statistical significance 8