High flow nasal cannula HFNC is a device that delivered the warmed and humid air on high flow rate through nose. It is used to treat severe respiratory distress in COVID-19 patients, a non-invasive ventilatory approach which is relative comfortable by using humidified and pre-heated air containing large concentration of oxygen. In acute respiratory failure HFNC is proven to be very effective and it also reduced the need of mechanical ventilation in severe patients. Apart from the supply of oxygen, HFNC generating positive airway pressure and decreasing the rebreathing from anatomical dead space.
