Background: COPD exacerbations add considerably to patients' burden because they: (1) cause frequent hospital admissions and relapses or readmissions, (2) contribute directly to the death of many patients, either during hospitalization or shortly thereafter, (3) cause patients significant stress, prolonged physical discomfort, disability and dramatically reduced quality of life, (4) consume the majority of the resources available to manage this chronic condition, (5) frequently progress to a severe stage warranting hospitalization before any abortive treatment is instituted, and (6) may hasten the progressive loss of lung function, a steady decline that is a cardinal feature of COPD itself. Hence, investigations of new therapies to treat COPD patients who are hospitalized with a severe exacerbation are desperately needed.