Patient Stratification
The clinical classifications were as follows: (1) non-severe ill
patients: mild, with fever, respiratory tract symptoms, and imaging
shows pneumonia, (2) severe ill patients: meet any of the following: a)
respiratory distress, respiratory rate ≥ 30 beats/min, b) in the resting
state, means oxygen saturation ≤ 93%, c) arterial blood oxygen partial
pressure / oxygen concentration ≤ 300mmHg (1mmHg = 0.133kPa), d)
respiratory failure occurs and requires mechanical ventilation, e) shock
occurs.