Evidence-based treatments for acute asthma.

Asthma is an important health care problem; over 12 million people in the United States suffer from asthma, the majority of whom are young patients. Presentations of acute asthma to emergency departments are common. In the United States, acute asthma presentations account for close to 2 million emergency department visits annually, and these patients often exhibit acute and chronic markers of severe asthma; so controlling asthma is important from many perspectives. We review the evidence for various acute asthma therapies, using the highest levels of evidence, employing systematic reviews (especially those from the Cochrane Collaboration) and evidence from randomized controlled trials to guide therapy decisions. beta agonists and systemic corticosteroids are the cornerstones of initial treatment. Delivery of beta agonists via nebulizer or metered-dose inhaler with spacer device appear to be similarly efficacious. However, recent evidence from studies involving children and adults indicate that addition of ipratropium bromide to early beta agonist treatments may reduce airway obstruction and reduce hospital admissions, especially for more severe asthma. Evidence from systematic reviews indicates that intravenous magnesium sulfate may provide similar benefits in severe asthma. Antibiotics, intravenous beta agonists, and intravenous aminophylline have been shown to add little and may increase adverse effects. Treatment for discharged patients should include systemic corticosteroids for 5-7 days, for all but the mildest asthma. Addition of inhaled corticosteroids should be considered for most patients, since evidence suggests that inhaled corticosteroids may reduce relapses and improve quality of life. Alternative treatments such as long-acting beta agonists and leukotriene antagonists remain unproven in this setting. Linking a discharge plan to close follow-up and asthma education (especially an action plan) needs to be encouraged. Acute asthma is a common problem and treatment has improved dramatically over the past 10 years. Employing the evidence-based practice outlined above should reduce the burden of acute asthma on patients and the health care system.