Leakage from non-invasive positive pressure ventilation therapy masks affects fraction of inspired oxygen: comparison of homeand institution-delivered oxygen therapy on simulated patients with chronic obstructive pulmonary disease

At-home non-invasive positive pressure ventilation (NPPV) has been shown to be effective in patients with chronic obstructive pulmonary disease (COPD). Especially in COPD patients with reduced ventilation capacity, NPPV can improve patients' symptoms and quality of life in combination with home oxygen therapy (HOT). Nevertheless, the mask is not attached properly, airway leakage would occur to decrease the fraction of inspired oxygen (FiO2) supplied to the alveoli. While the effectiveness of oxygen therapy is dependent upon the FiO2, there is a lack of basis data to establish guidelines regarding the standard FiO2 level required for the combined use of NPPV and HOT. In the present study, we simulated patients with COPD to determine whether leaks from the mask affect the supply of FiO2 to the alveoli during NPPV oxygen therapy. Comparing FiO2 values from simulated medical institution care (oxygen piping + NPPV) and home medical care (HOT + NPPV), while no decrease in FiO2 levels was observed in cases at medical institutions, a statistically significant decrease in FiO2 levels (with increasing leakage) was found in cases in at-home care. These results are clinically relevant, as they suggest that FiO2 levels should be carefully monitored during at-home mechanical ventilation.