LAUSR

PURPOSE To determine the association between lung collapse and treatment failure in high-flow nasal cannula oxygen therapy (HFNC) or noninvasive ventilation (NIV). METHODS We performed a quantitative analysis of chest computed tomography in patients with de novo acute respiratory failure who received HFNC (HFNC group) or NIV (NIV group) between January 2012 and December 2017. In the HFNC and NIV group, the nonaerated lung weight were compared between patients in whom respiratory treatment succeeded or failed, respectively. We used logistic regression to examine the association between the nonaerated lung weight and treatment failure. RESULTS Treatment failed in 70/118 (59%) patients in the HFNC group and 66/101 (65%) patients in the NIV group. The nonaerated lung weight was significantly greater in unsuccessfully treated patients than in successfully treated patients in the HFNC group (p = 0.005), but not in the NIV group (p = 0.535). Logistic regression revealed that greater nonaerated lung weight was associated with increased risk of HFNC failure (adjusted odds ratio 1.30 per 5% increase, 95% confidence interval 1.09-1.55, p = 0.003) but not of NIV failure. CONCLUSIONS Patients with a greater nonaerated lung weight had a higher risk of HFNC failure, but not of NIV failure.