Effect of CPAP on 6-Minute Walk Test Outcomes in Patients With ECAC

Inclusion Criteria: * Patient with a diagnosis of ECAC either via bronchoscopy or CT Scan * Age \> 18 years * Patients that will undergo a diagnostic or therapeutic bronchoscopy as part of their standard of care * Patients with a baseline 6 MWT * Patients that have never used CPAP devices in the past Exclusion Criteria: * Patients with poorly-controlled respiratory comorbidities (asthma, COPD, obstructed sleep apnea, GERD, relapsing polychondritis) * No evidence for acute respiratory tract infection, or respiratory tract infection within the prior 3 weeks * Resting bradycardia (\<50 beats/min), frequent multifocal PVCs, complex ventricular arrhythmia, sustained SVT * Dysrhythmia that might pose a risk during exercise or training * Any disease or condition that interferes with completion of initial or follow-up assessments * Subject has co-morbidities that may significantly reduce subject's ability to improve exercise capacity (e.g., severe arthritis, planned knee surgery) or baseline limitation on 6MWT is not due to dyspnea. * Subject has an inability to walk \>140m (150 yd) in 6 minutes * Subject has an inability to tolerate bronchoscopy under moderate sedation or general anesthesia. * Subject has a known sensitivity to drugs required to perform bronchoscopy.