Emergency Medicine The Affiliated Suqian Hospital of Xuzhou Medical University Suqian 223800 Jiangsu Province China;
Intensive Care Unit The Infectious Disease Control Center Suqian 223800 Jiangsu Province China;
Emergency Medicine The Affiliated Suqian Hospital of Xuzhou Medical University Suqian 223800 Jiangsu Province China;
Emergency Medicine Nanjing Drum Tower Hospital Nanjing University Medical School Nanjing 210008 Jiangsu Province China;
COVID-19; Hypoxemia; High-flow nasal oxygen; Intubation and prone position; Case report;