Portable Continuous Positive Airways Pressure (CPAP) in Excessive Central Airway Collapse (ECAC) Study

Exclusion Criteria

• •Patients with dynamic collapse of only segmental airways
• •Comorbidity which is likely to be an additional limiting factor in exercise tolerance
• •Contraindication to CPAP
• •Contraindication to incremental shuttle walk testing (ISWT), including; myocardial infarction within the last 3-5 days, unstable angina, uncontrolled arrhythmia, severe symptomatic cardiac or valvular disease, acute pulmonary embolus, uncontrolled asthma, syncope, mental impairment resulting in inability to perform test.
• •Resting oxygen saturations \<90% on air or need for ambulatory oxygen therapy
• •Immobility that would make ISWT unfeasible
• •Severe emphysema
• •Acute infectious disease
• •Acute respiratory illness