Table 2.

Classification of symptomatic COVID-19 patients

Severity	O2 saturation (SpO2)	Hemodynamic stability	O2 support	Other symptoms	CT chest
Mild pneumonia	Mild or no change at rest (SpO2 of 92–94%)	Stable	Low-flow oxygen	No	Normal
Moderate pneumonia	Drop in SpO2 during activity	Tachycardia and hemodynamic variability	High-flow oxygen (HFO) system/venturi mask	Fever, cough, breathlessness	Ground glass opacities and bilateral lung mottling
Severe	Needs high FiO2 and PEEP to maintain oxygenation	Unstable/altered hemodynamics needs respiratory support	Mechanical ventilator (MV) or noninvasive ventilation (NIV)	Altered mental status, Signs of ARDS (mild to severe)8	ARDS changes
Critical	Needs high FiO2 and PEEP to maintain oxygenation	Unstable/altered hemodynamics needs respiratory support	Mechanical ventilator or on extracorporeal membrane oxygenation (ECMO)	ARDS, multiorgan failure, sepsis, shock	ARDS changes bilateral ground glass appearance