Effects of a novel noninvasive open ventilation system during constant work rate exercise in COPD

Exercise intolerance limits daily activities of COPD patients. Noninvasive ventilation improves exercise capacity in severe COPD, but previous systems are impractical for ambulatory use. This study evaluated a 0.45 kg noninvasive open ventilation (NIOV) system (Breathe Technologies), designed for nasal delivery of compressed O 2 with each inhalation. This was a randomized single-blinded study of 10 men with severe-to-very severe COPD and exercise desaturation. Following a test day in which a cycle ergometer constant work rate (CWR) was established, subjects completed 3 additional days in which 2-3 CWR tests (separated by 1.5 hrs) were performed in random order. Tests were: unencumbered room air, NIOV+air, NIOV+O 2 , or O 2 via standard nasal cannula. Data collected included exercise time, SpO 2 and transcutaneous (Tc) PCO 2 . Subjects ages were 67±9y, with FEV 1 /FVC=29±6% and FEV 1 =30±12% pred. Compared to unencumbered and NIOV+air arms, endurance was prolonged ∼75% by nasal cannula O 2 and ∼330% by NIOV+O 2 (Table). The greater endurance in the NIOV+O 2 tests was accompanied by higher SpO 2 but unaltered TcPCO 2 . Exercise endurance was dramatically enhanced using the NIOV system+O 2 . These data suggest that this system is a practical means to improve tolerance of everyday activities in oxygen-dependent severe COPD.