Hospitalized exacerbations are particularly relevant in COPD patients. Hospitalized exacerbations result in a profound impact on patient survival, function, symptoms and health status as well as costs Hospitalizations accounted for a significant component of COPD related costs. Re-hospitalization in COPD is frequent and associated with a particularly negative impact. Patients discharged from the hospital after a COPD exacerbation have a high mortality and are frequently readmitted with recurrent exacerbations. The cause of these high rates of readmission is not well understood. Although a number of pharmacologic and behavioral interventions have been used to decrease exacerbations in COPD, it is not clear that these same interventions are successful in reducing hospital admission rates or re-admission rates. Except for the use of noninvasive ventilation in patients that present in acute respiratory failure during COPD hospitalization, no new therapies have been discovered in the last 3 decades. Hence, investigations of new therapies to treat COPD patients who are hospitalized with a severe exacerbation are desperately needed.