Chronic obstructive pulmonary disease in the emergency department.

Acute asthma and chronic obstructive pulmonary disease (COPD) exacerbations are the most common respiratory diseases requiring emergent medical evaluation and treatment. Asthma and COPD are chronic, debilitating disease processes that have been differentiated traditionally by the presence or absence of reversible airflow obstruction. Asthma and COPD exacerbations impose an enormous economic burden on the US health care budget. In daily clinical practice, it is difficult to differentiate these 2 obstructive processes based on their symptoms, and on their nearly identical acute treatment strategies; major differences are important when discussing anatomic sites involved, long-term prognosis, and the nature of inflammatory markers.