In case of temporary interruption of the intervention for any cause, patients should receive oxygen supplementation with Venturi mask with a target of SpO2 88-92%.The comparator will be non invasive ventilation (NIV). NIV must be delivered by full or oronasal mask. The ventilator settings will be decided according to the usual practice: maximal tolerated inspiratory pressure to obtain a measured or estimated expired tidal volume of 6-8 mL·kg-1 of body weight and a positive end expiratory pressure (PEEP) between 3 and 5 cmH2O. An interface rotational strategy will be allowed among only different types of masks.