1. Adult patients confirmed by 2019-nCov throat swab or other samples of nucleic acid positive, 2. Patients with clear manifestations of pulmonary exudation on chest imaging, 3. Patients requiring oxygen therapy or mechanical ventilation, ARDS (oxygenation index < 200mmHg) was diagnosed according to the Berlin standard in 2012.

1. Adult patients confirmed by 2019-nCov throat swab or other samples of nucleic acid positive, 2. Patients with clear manifestations of pulmonary exudation on chest imaging, 3. Patients requiring oxygen therapy or mechanical ventilation, ARDS (oxygenation index < 200mmHg) was diagnosed according to the Berlin standard in 2012.