High flow nasal cannula in extubated patients: is it advantageous over conventional oxygen therapy?

Following successful ventilator weaning and extubation, patients off invasive ventilation frequently suffer respiratory insufficiency, hypoxemia in particular, usually necessitating oxygen therapy via non-rebreather mask, Venturi mask or subsequent use of non-invasive ventilation (1). High-flow nasal cannula (HFNC) is a new device of oxygen therapy which comprises an air/oxygen blender, an active humidifier, a single heated circuit, and a large-diameter nasal cannula. HFNC delivers medical gas that was adequately heated and humidified, and may reduce upper airway dead space and resistance, PEEP impacts and re-expansion pulmonary alveoli (2). However, it remains undetermined whether HFNC is advantageous over conventional oxygen therapy in prevention and treatment of post-extubation respiratory failure