@article {Valsecchi3612785, author = {Carlo Valsecchi and Eduardo Diaz Delgado and Shaun Smith and Sara Foote and Bijan Safaee Fakhr and Caio Cesar Araujo Morais and Daniel Chipman and William Purris F and Carolyn LaVita and Lorenzo Berra}, title = {The Use of HFNC in COVID-19 Patients}, volume = {66}, number = {Suppl 10}, elocation-id = {3612785}, year = {2021}, publisher = {Respiratory Care}, abstract = {Background: High-flow nasal cannula has been suggested to reduce endotracheal intubation in hypoxic acute respiratory failure and ventilator usage during the coronavirus disease 2019 (COVID-19) pandemic. In this study, we characterize the prevalence and clinical features of patients with COVID-19 treated with HFNC, define factors associated with HFNC failure, and describe the respiratory mechanics after intubation. Methods: We performed a single-center prospective observational study on COVID-19 patients with respiratory failure who failed the conventional oxygen (O2) therapy from September 2020 and April 2021. This study was approved by the local IRB. The decision to start the HFNC was made following the institutional protocol. We collected data on demographics, past medical history and laboratory results, vital signs, and ROX index (defined as peripherical saturation of O2/inspired fraction of O2/respiratory rate) during HFNC treatment and entire HFNC time use. Tracheal intubation decision was made by the clinicians caring for the patient. If intubation occurred, we recorded data about compliance of the respiratory system (CRS) and oxygenation at intubation and 24 h later. Results: We enrolled 153 patients. Hospital mortality was 29\% and associated with the presence of hypertension, chronic kidney disease (CKD), coronary artery disease (CAD), and advanced age. 19\% of the patients were successfully weaned from HFNC. Diabetes was associated with an increased risk of HFNC failure. ROX index \> 4 at 6 and 12 h after the initiation of HFNC was respectively 75\% and 90\% sensitive for detecting patients who will be successfully weaned from HFNC. FIO2 during HFNC was statistically higher in the intubated group. After intubation, the CRS was statistically different between the deceased (mean 30 mL/cm H2O) compared with the survivors (mean 36 mL/cm H2O), but PaO2/FIO2 ratio was not statistically different. Conclusions: In COVID-19 patients with respiratory failure who failed conventional O2 therapy, 19\% receiving HFNC were never intubated. Predictive factors of HFNC failure were diabetes mellitus, ROX index lower than 4.88, and high FIO2 requirement. Age, hypertension, CAD, and CKD increased the risk of mortality. After intubation, the compliance was lower in deceased patients compared with the patients who survived. The severity of oxygenation index correlated with the increased likelihood of intubation but not with death. View this table:}, issn = {0020-1324}, URL = {https://rc.rcjournal.com/content/66/Suppl_10/3612785}, eprint = {https://rc.rcjournal.com/content}, journal = {Respiratory Care} }