[Non-invasive respiratory support in acute respiratory distress]

Conventional oxygen therapy could be delivered via nasal prongs, face mask, venturi mask, or non-rebreather mask. High flow nasal cannula (HFNC) produces a higher flow of FiO2. This higher flow creates a positive pressure on the higher respiratory tract. Collapsed alveoli could be opened due to this positive pressure and CO2 would be eliminated. This improves the oxygenation and reduces the total work of breathing. Continuous positive pressure support (CPAP) realizes a continuous positive expiratory pressure to the respiratory tract, which opens the alveoli and reduces the pre-load by reducing the venous return. Non-invasive ventilation (NIV) improves ventilation and reduces the work of breathing. Initiating use of HFNC, CPAP or NIV can prevent intubation but the response should be carefully evaluated after 1-2 hours to not delay intubation.