Uncomplicated disease	Upper respiratory symptoms (e.g. odynophagia, cough, and nasal congestion) either or not associated with fever and myalgias, with no criteria for severity.
Non-severe pneumonia	Fever associated with respiratory symptoms and a radiologic infiltrate, without criteria for severe pneumonia.
Severe pneumonia	According to the IDSA/ATS(41) criteria
	- ≥ 1 major criterion
	Septic shock
	Mechanic ventilation
	- ≥ 3 minor criteria
	Confusion
	Respiratory rate ≥ 30rpm
	Hypotension with aggressive fluid resuscitation
	Hypothermia (central temperature < 36ºC)
	PaO2/FiO2 ≤ 250mmHg
	BUN ≥ 43mg/dL
	Leucopenia (leucocytes ≤ 4,000/µL)
	Thrombocytopenia (platelets ≤ 100,000/µL)
SDRA
	Acute hypoxemic respiratory failure (PaO2/FiO2 ≤ 300 with PEEP/CPAP ≥ 5cmH2O) (starting < 1 week after know risk factor) characterized by bilateral opacities (not explained by effusion, atelectasis or nodules) and not explained by heart failure or fluid overload (exclusion by means of clinical, laboratory and echocardiographic assessment).
Sepse	According to the Surviving Sepsis Campaign43 criteria
	Life-threatening organs dysfunction (clinically evidenced as acute ≥ 2 points increase of SOFA score) caused by dysregulated host response to infection
Choque séptico	According to the Surviving Sepsis Campaign43 criteria
	A subset of patients with sepsis (clinically identified for serum lactate > 2 mmol/L in the absence of hypovolemia and requiring vasopressors to maintain mean blood pressure ≥ 65 mmHg), with unique circulatory/cellular/metabolic changes entailing increased mortality.

Source: adapted from World Health Organization (WHO). Clinical management of severe acute respiratory infection when Novel coronavirus (2019-nCoV) infection is suspected. Interim guidance. 28 January 2020. Available from: https://www.who.int/docs/default-source/coronaviruse/clinical-management-of-novel-cov.pdf.⁽¹³⁾

IDS/ATS - Infectious Diseases Society of America/American Thoracic Society; PaO₂/FiO₂ - partial oxygen pressure/fraction of inspired oxygen; PEEP/CPAP - positive end-expiratory pressure/continuous positive airway pressure; ARDS - adult respiratory distress syndrome; SOFA - Sequential Organ Failure Assessment.