Methods: In this single-center, retrospective, observational study, we enrolled patients with confirmed severe COVID-19 admitted to Renmin Hospital of Wuhan university (Wuhan, China) from 1 February 2020 to 26 March 26 2020. Epidemiological, clinical, and laboratory data, and treatments and outcomes upon hospital admission, were obtained from electronic medical records. Sequential organ failure assessment (SOFA) scores were calculated.Results: Of 54 patients with severe COVID-19, HFNC was successful in 28 (51.9%) and unsuccessful in 26 (48.1%). HFNC failure was seen more commonly in patients aged ≥60 years and in men. In addition, compared with patients successfully treated with HFNC, patients with HFNC failure had the following characteristics: higher percentage of fatigue and anorexia as well as cardiovascular disease; increased time from onset to diagnosis and SOFA scores; elevated body temperature, respiratory rate, and heart rate; more complications including ARDS, septic shock, myocardial damage, and acute kidney injury; increased neutrophil counts and prothrombin time; and decreased arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2) (all P < 0.05). However, binary logistic regression analysis showed that only male gender and PaO2/FiO2 were independent risk factors significantly associated with HFNC failure (both, P < 0.05). Conclusion: Patients with severe COVID-19 had a high HFNC treatment failure rate. Male gender and decreased PaO2/FiO2 were independent risk factors associated with HFNC failure in severe COVID-19 patients.

Background: Acute hypoxemic respiratory failure is prevalent in severe Coronavirus Disease 2019 (COVID-19). High-flow nasal canula oxygen therapy (HFNC) is currently one of the most common ventilation strategies for COVID-19 patients with respiratory failure. This study is to analyze the risk factors associated with HFNC failure in patients with severe COVID-19.Methods: In this single-center, retrospective, observational study, we enrolled patients with confirmed severe COVID-19 admitted to Renmin Hospital of Wuhan university (Wuhan, China) from 1 February 2020 to 26 March 26 2020. Epidemiological, clinical, and laboratory data, and treatments and outcomes upon hospital admission, were obtained from electronic medical records. Sequential organ failure assessment (SOFA) scores were calculated.Results: Of 54 patients with severe COVID-19, HFNC was successful in 28 (51.9%) and unsuccessful in 26 (48.1%). HFNC failure was seen more commonly in patients aged ≥60 years and in men. In addition, compared with patients successfully treated with HFNC, patients with HFNC failure had the following characteristics: higher percentage of fatigue and anorexia as well as cardiovascular disease; increased time from onset to diagnosis and SOFA scores; elevated body temperature, respiratory rate, and heart rate; more complications including ARDS, septic shock, myocardial damage, and acute kidney injury; increased C-reactive protein, neutrophil counts and prothrombin time; and decreased arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2) (all P < 0.05). However, binary logistic regression analysis showed that only male, PaO2/FiO2 and SOFA scores were independent risk factors significantly associated with HFNC failure (all P < 0.05). Conclusion: Patients with severe COVID-19 had a high HFNC treatment failure rate. Male, low PaO2/FiO2 and SOFA scores were independent risk factors associated with HFNC failure in severe COVID-19 patients. However, studies with larger sample sizes or multi-center studies are warranted.