- Asthma is the most common chronic disease of childhood and is associated with significant morbidity and mortality.
- Inhaled albuterol remains the first line therapy for acute asthmatic exacerbations. Delivery of albuterol by metered dose inhaler has been shown to be superior to delivery by nebulization.
- Inhaled levoalbuterol has not been shown to have any significant benefit over racemic albuterol in acute asthma exacerbations.
- The addition of nebulized ipratroprium to the first 2 to 3 albuterol doses has been associated with a decreased need for hospitalization in pediatric patients with moderate-to-severe asthma exacerbations.
- Administration of oral corticosteroids in the emergency department has been shown to enhance recovery from an acute asthma exacerbation and decrease rates of hospitalization.
- Oral dexamethasone (one–two doses) has been shown to be as efficacious as a 5-day course of oral prednisone.
- Magnesium sulfate may be of benefit in patients with moderate-to-severe exacerbations who do not respond to initial bronchodilator therapy.
- Heliox has been suggested to be of benefit for patients with severe asthma exacerbations in small clinical trials, but convincing evidence of its benefit is not available.
Asthma is the most common chronic disease of childhood.1 The current prevalence of asthma in the United States is estimated at 8.9%. It is the third most common reason for hospitalization of children in the United States, exceeded only by injuries and pneumonia. Acute exacerbations of asthma are often managed in emergency departments (EDs). In 2004, the number of children who sought care for an acute asthma exacerbation in a U.S. ED reached 754,000.2
Asthma is traditionally defined as intermittent, reversible obstructive airway disease. It is now known to be a chronic inflammatory disorder of the airways. The most recent National Heart Lung and Blood Institute (NHLBI) expert panel guidelines on the diagnosis and management of asthma define asthma as: a common chronic disorder of the airways that is complex and characterized by variable and recurring symptoms, airflow obstruction, bronchial hyperresponsiveness, and an underlying inflammation. The interaction of these features of asthma determines the clinical manifestations and severity of asthma and the response to treatment.3
The major mechanisms thought to contribute to the pathophysiology of asthma are increased airway responsiveness, inflammation, mucus production, and submucosal edema. Airway responsiveness is defined as the ease with which airways narrow in response to various nonallergic stimuli. These stimuli include inhaled pharmacologic agents, such as histamine and methacholine, and physical stimuli, such as exercise. The level of airway responsiveness is reported to correlate with the severity of asthma symptoms and medication requirements. The critical role of airway inflammation in both the development of obstruction and the degree of hyperresponsiveness has been appreciated only recently. Pathologic specimens from patients demonstrate inflammation of the airways even in the mildest forms of the disease. Increased mucus production and submucosal edema add to the obstruction that occurs secondary to bronchospasm and inflammation.
These three components are synergistic and their relationship ...