Background
dyspnea, COPD
COPD, COLLAPSE, CHRONIC OBSTRUCTIVE PULMONARY DISEASE
Chronic obstructive pulmonary disease (COPD) is characterized by persistent and not fully reversible airflow limitation, with high economic and social burden, high morbidity and mortality worldwide [Therefore, reversing DH is important for patients with COPD or Pre-COPD to reduce dyspnea and improve exercise capacity [PEP devices have been wildly used to produce a reduction of breathing frequency and expiratory flow limitation, change breathing pattern, improve gas exchange, as well as result in less airway collapse and air-trapping in patients with COPD [However, to our knowledge, few studies to date have explored the effects of long-term domiciliary use of PEP devices on exercise capacity in patients with COPD or Pre-COPD. Therefore, this study aimed to evaluate the effects and safety of long-term domiciliary use of PEP delivered by a spring-loaded resistor face mask in patients with COPD or Pre-COPD.