Table 1.

Acute PNeumonia early assessment (aPNea) score points.

	Points
Need for hospitalization independent of COVID-19 severity	5
Respiratory rate >30 acts per minute	5
Arterial partial pressure of oxygen <60 mm Hg	5
Horowitz index <300	5
Horowitz index <330 and measured A-a O2 gradient ≥2 times than expected by age measured A-a O2 gradient <2 times than expected by age	4 2
Positive 6-min walk test	2
Lung parenchymal involvement ≥50% on the best available lung imaging	2
Lung parenchymal involvement <50% on the best available lung imaging	1
Fever >38 °C in the previous 7 days	1
Plasma D-dimer levels >1000 ng/mL FEU	1

The Horowitz index was calculated as the arterial partial pressure of oxygen in mm Hg divided by the fraction of inspired oxygen. A-a, alveolar to arterial; FEU, fibrinogen equivalent units.