Physiological and clinical characteristics of patients with COPD admitted to an inpatient pulmonary rehabilitation program: A real-life study

Background and objective: Patient selection criteria and experimental interventions of randomized controlled trials may not reflect how things work in practice. The aim of this study was to describe the characteristics of chronic obstructive pulmonary disease (COPD) patients undergoing an inpatient pulmonary rehabilitation program (PRP) and the correlates of success. Methods: Retrospective database review of 975 consecutive patients transferred from acute care hospitals after an acute exacerbation (group A: 14.6%) or admitted from home (group B: 75.4%), from 2010 to 2017. Patients were also divided according to the associated registered main diagnosis: COPD (group 1: 30.6%); COPD and respiratory failure (group 2: 51.7%); COPD and obstructive sleep apnea (group 3: 17.6%). Baseline correlates of post-PRP changes in six minute walking test (6MWT) were also evaluated. Results: Global Initiative for Chronic Obstructive Lung Disease stages 3 and 4 were the most commonly represented in group 2 (p = 0.0001). Comorbidity Index of all patients was 3.9 ± 1.8. The overall in-hospital mortality rate was 1.3% (5.6% vs 0.6%, in groups A and B, respectively; p = 0.0001). Hypertension, cardiac diseases and obesity were observed in 65.2, 52.2 and 29.6% of patients, respectively. Post-PRP 6MWT increased in all groups. Age, male gender, airway obstruction and baseline 6MWT were correlated with a post-PRP 30 meter increase in 6MWT. Conclusion: Confirming data of literature, this real-life study shows the characteristics of COPD patients undergoing an inpatient PRP with significant improvement in exercise capacity, independent of whether in stable state or after a recent exacerbation or of the associated main diagnosis. Keywords: Exercise training, COPD, Comorbidities, Exercise capacity, Respiratory failure, OSA