Even with current standard ED treatments 20-25% of patients presenting to the ED with an acute asthma episode will still require hospitalization. For patients unresponsive to beta-agonists the admit rates will be higher. Of those well enough to be discharged from the ED nearly 30% will relapse within one month. More than 5,000 patients with asthma still die each year in the USA. For patients who do not respond to beta-agonists, there are relatively few treatment options for rapid improvement of symptoms and pulmonary function. Presumably, mucous secretion and plugging play an important role in the pathogenesis of severe asthma unresponsive to beta-agonists. The use of agents to promote clearance of intra-luminal secretions and mucous plugs may represent an important advance in the management of acutely ill asthmatics, both to hasten recovery and prevent deterioration in the acute care setting and to prevent relapse after discharge from the ED.