We assessed the effect of altering inspired gas on the 6MWT distance in COPD. We hypothesized that HeO2 would improve walking distance and reduce shortness of breath compared to both RA and O2, and potentially improve quality of life for COPD patients.

We hypothesized that inspiring helium-hyperoxia (HeO2) would significantly improve 6-minute walking test (6MWT) distance in Chronic Obstructive Pulmonary Disease (COPD) subjects.

This was a blinded, randomized crossover study. At Visit 1 we assessed pulmonary function, exercise capacity and 6MWT distance. Visits 2 and 3 consisted of four 6MWT with different inspired gases: room air by mask (RA), 100% O2 by mask (Mask O2), 100% O2 by nasal prongs (Nasal O2), and 70% He/30% O2 by mask (HeO2). Walking distance, shortness of breath, leg fatigue, O2 saturation and heart rate (HR) were assessed

Inclusion Criteria:

• Exertional dyspnea
• Activity limitation
• COPD

Exclusion Criteria:

• Recent exacerbation (< 4 wks)
• Supplemental O2
• Significant cardiovascular/musculoskeletal abnormalities