settings where there is limited availability of mechanical ventilation (27). This applies for care of children and adults. 6. Management of severe COVID-19: treatment of co-infections Give empiric antimicrobials to treat all likely pathogens causing SARI and sepsis as soon as possible, within 1 hour of initial assessment for patients with sepsis. Remark 1: Although the patient may be suspected to have COVID-19, administer appropriate empiric antimicrobials within 1 hour of identification of sepsis (5). Empiric antibiotic treatment should be based on the clinical diagnosis (community-acquired pneumonia, health care-associated pneumonia [if infection was acquired in health care setting] or sepsis), local epidemiology and susceptibility data, and national treatment guidelines. Remark 2: When there is ongoing local circulation of seasonal influenza, empiric therapy with a neuraminidase inhibitor should be considered for the treatment for patients with influenza or at risk for severe disease (5). Empiric therapy should be de-escalated on the basis of microbiology results and clinical judgment. 7. Management of critical COVID-19: acute respiratory distress syndrome (ARDS) Recognize severe hypoxemic respiratory failure when a patient with respiratory distress is failing to respond to standard oxygen therapy and prepare to provide advanced oxygen/ventilatory support. Remarks: Patients may continue to have increased work of breathing or hypoxemia even when oxygen is delivered via a face mask with reservoir bag (flow rates of 10–15 L/min, which is typically the minimum flow required to maintain bag inflation; FiO2 0.60–0.95). Hypoxemic respiratory failure in ARDS commonly results from intrapulmonary ventilation-perfusion mismatch or shunt and usually requires mechanical ventilation (5). Endotracheal intubation should be performed by a trained and experienced provider using airborne precautions. Remarks: Patients with ARDS, especially young children or those who are obese or pregnant, may desaturate quickly during intubation. Pre-oxygenate with 100% FiO2 for 5 minutes, via a face mask with reservoir bag, bag-valve mask, HFNO or NIV. Rapid-sequence intubation is appropriate after an airway assessment that identifies no signs of difficult intubation (28, 29,.30). The following recommendations pertain to mechanically ventilated adults and paediatric patients with ARDS (5, 31). Implement mechanical ventilation using lower tidal volumes (4–8 mL/kg predicted body weight, PBW) and lower inspiratory pressures (plateau pressure < 30 cmH2O). Remarks for adults: This is a strong recommendation from a clinical guideline for patients with ARDS (5), and is suggested for patients with sepsis-induced respiratory failure who do not meet ARDS criteria (5). The initial tidal volume is 6 mL/kg PBW; tidal volume up to 8 mL/kg PBW is allowed if undesirable side effects occur (e.g. dyssynchrony, pH < 7.15). Permissive hypercapnia is permitted. Ventilator protocols are available (32). The use of deep sedation may be required to control respiratory drive and achieve tidal volume targets. Remarks for children: In children, a lower level of plateau pressure (< 28 cmH2O) is targeted, and lower target of pH is permitted (7.15–7.30). Tidal volumes should be adapted to disease severity: 3–6 mL/kg PBW in the case of poor respiratory system compliance, and 5–8 mL/kg PBW with better preserved compliance (31). In adult patients with severe ARDS, prone ventilation for 12–16 hours per day is recommended. Remarks for adults and children: Application of prone ventilation is strongly recommended for adult patients, and may be 7 Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected: Interim guidance considered for paediatric patients with severe ARDS but requires sufficient human resources and expertise to be performed safely; protocols (including videos) are available (33, 34) (https://www.nejm.org/doi/full/10.1056/NEJMoa1214103). Remark for pregnant women: There is little evidence on prone positioning in pregnant women. Pregnant women may benefit from being placed in the lateral decubitus position. Use a conservative fluid management strategy for ARDS patients without tissue hypoperfusion. Remarks for adults and children: This is a strong guideline recommendation (5); the main effect is to shorten the duration of ventilation. See reference (35) for details of a sample protocol. In patients with moderate or severe ARDS, higher PEEP instead of lower PEEP issuggested. Remark 1: PEEP titration requires consideration of benefits (reducing atelectrauma and improving alveolar recruitment) vs risks (end-inspiratory overdistension leading to lung injury and higher pulmonary vascular resistance). Tables are available to guide PEEP titration based on the FiO2 required to maintain SpO2 (32). In younger children, maximal PEEP rates are 15 cmH2O. Although high driving pressure (plateau pressure − PEEP) may more accurately predict increased mortality in ARDS compared with high tidal volume or plateau pressure (36), data from RCTs of ventilation strategies that target driving pressure are not currently available. Remark 2: A related intervention of recruitment manoeuvres (RMs) is delivered as episodic periods of high continuous positive airway pressure (CPAP) (30–