High flow nasal cannula (HFNC) provides high concentration oxygen in a high flow, which exceeds patient's inspiratory flow demand, to improve oxygenation. In a recent meta-analysis of seven trials with 1771 patients, HFNC was shown to improve oxygenation and avoid intubation in patients with severe hypoxemia. The high velocity of the gas can rinse the dead space of the upper airway and reduce CO2 rebreathing, reduce COPD patients' work of breathing and improve the dynamic compliance of respiratory system.
Thus, we proposed a randomized controlled trial to investigate the value of high flow nasal cannula in weaning AECOPD patients from invasive ventilation, with comparison of noninvasive ventilation.
