. 2021 Oct 29;174:105955. doi: 10.1016/j.phrs.2021.105955

Table 3.

Definition of severe COVID-19 in the Diagnosis and treatment of COVID-19 (8th trial edition).

Adults meet any of the following criteria:

1. Shortness of breath, respiratory rate (RR) ≥ 30 breaths/min;

2. Oxygen saturation ≤ 93% on air inhalation at rest state;

3. Arterial partial pressure of oxygen (PaO₂)/inhaled oxygen concentration (FiO₂) ≤ 300 mmHg (1 mmHg = 0.133 kPa); Note: The PaO₂/FiO₂should be corrected according to the following formula in high altitude (over 1000 m above sea level) areas: PaO₂/FiO₂× [760/atmosphere (mmHg)].

4. Progressive worsening of clinical symptoms and lung imaging showing a significant progression of lesions > 50% within 24–48 h.

The child meets any of the following criteria:

1. Persistent high fever for more than 3 days;

2. Shortness of breath (<2 months of age, RR ≥ 60 beats/min; 2–12 months of age, RR ≥ 50 beats/min; 1–5 years of age, RR ≥ 40 beats/min; >5 years of age, RR ≥ 30 beats/min), except for the effects of fever and crying;

3. Resting state, oxygen saturation ≤ 93% during air inhalation;

4. Assisted breathing (nasal flapping, trigeminal sign);

5. Drowsiness, convulsions;

6. Refusal of food or feeding difficulties, with signs of dehydration.