Pulse oximetric saturation to fraction of inspired oxygen (SpO(2)/FIO(2)) ratio 24 hours after high-flow nasal cannula (HFNC) initiation is a good predictor of HFNC therapy in patients with acute exacerbation of interstitial lung disease

BACKGROUND: High-flow nasal cannula (HFNC) oxygen therapy provides effective respiratory management in patients with hypoxemic respiratory failure. However, the efficacy and tolerability of HFNC for patients with acute exacerbation of interstitial lung disease (AE-ILD) have not been established. This study was performed to assess the efficacy and tolerability of HFNC for patients with AE-ILD and identify the early predictors of the outcome of HFNC treatment. METHODS: We retrospectively reviewed the records of patients with AE-ILD who underwent HFNC. Overall survival, the success rate of HFNC treatment, adverse events, temporary interruption of treatment, discontinuation of treatment at the patient’s request, and predictors of the outcome of HFNC treatment were evaluated. RESULTS: A total of 66 patients were analyzed. Of these, 26 patients (39.4%) showed improved oxygenation and were successfully withdrawn from HFNC. The 30-day survival rate was 48.5%. No discontinuations at the patient’s request were observed, and no serious adverse events occurred. The pulse oximetric saturation to fraction of inspired oxygen (SpO(2)/FIO(2)) ratio 24 h after initiating HFNC showed high prediction accuracy (area under the receiver operating characteristic curve, 0.802) for successful HFNC treatment. In the multivariate logistic regression analysis, an SpO(2)/FIO(2) ratio of at least 170.9 at 24 h after initiation was significantly associated with successful HFNC treatment (odds ratio, 51.3; 95% confidence interval, 6.13–430; p < 0.001). CONCLUSIONS: HFNC was well tolerated in patients with AE-ILD, suggesting that HFNC is a reasonable respiratory management for these patients. The SpO(2)/FIO(2) ratio 24 h after initiating HFNC was a good predictor of successful HFNC treatment. The reviews of this paper are available via the supplemental material section.