Source: World Health Organization, June 2020, adapted.
* Acronyms: ARI, acute respiratory infection; BP, blood pressure; bpm, beats/minute; CPAP, continuous positive airway pressure; FiO2, a fraction of inspired oxygen; MAP, mean arterial pressure; NIV, non-invasive ventilation; OI, oxygenation index; OIU, oxygenation index using SpO2; PaO2, partial pressure of oxygen; Peep, positive end-expiratory pressure; SBP, systolic blood pressure; SD, standard deviation; SIRS, systemic inflammatory response syndrome; SAOF, sequential assessment of organ failure; SpO2, oxygen saturation.