DUET Versus Standard Interface for Hypercapnic COPD Patients

This trial is comparing two types of face masks used during non-invasive ventilation (breathing support through a mask, not a breathing tube) for people with COPD who are having a flare-up with dangerously high carbon dioxide levels. One mask is a standard mask; the other is a newer type called DUET. **You may be eligible if...** - You are having an acute flare-up of COPD - Your blood gas tests show that your carbon dioxide is too high (above 45 mmHg) and your blood pH is between 7.25 and 7.35 (mild to moderate acidosis) **You may NOT be eligible if...** - You have a severe facial deformity, facial burns, or a fixed blockage in your upper airway - You need an emergency breathing tube (e.g., you are unconscious, in respiratory arrest, or have uncontrolled agitation) - You have had a large amount of material inhaled into your lungs - You have a life-threatening heart rhythm problem - You are in severe shock that does not respond to fluids or medications - You have critically low oxygen levels in your blood Talk to your doctor to see if this trial is right for you.