Respiratory distress after extubation is associated with increased morbidity and mortality. Its multifactorial pathophysiology causes a loss of pulmonary aeration during the weaning process, the clinical translation being impaired gas exchange and the occurrence of respiratory distress. Lung ultrasound can accurately quantify the loss of pulmonary aeration before, after end during the weaning trial by calculating the Lung Ultrasound Score (LUS). Investigators have recently demonstrated in a prospective two-center study of 100 patients that the intensity of the lung aeration loss occurring during the weaning trial, was predictive of the development of postextubation respiratory distress within 48 hours following extubation. A LUS ≥ 14 could identify patients at high risk of developing postextubation respiratory distress. A second study that investigators have just completed in 80 patients weaned from mechanical ventilation shows a 30% reduction of respiratory distress in post-extubation High Flow Nasal Cannula oxygen group compared to a standard O2 group.

The establishment of a targeted therapeutic strategy proposed in a group of high-risk patients, defined as having a ≥ 14 LUS at the end of the weaning trial could reduce the incidence of extubation failure and associated morbidity and mortality.

Inclusion Criteria:

• patients above 18, mechanically ventilated on tracheal intubation for more than 48 hours.

Exclusion Criteria:

• Patients with chronic obstructive pulmonary disease (COPD) with moderate to severe (3 and 4) stage defined by a forced expiratory volume in one second (FEV) <50% of theoretical value
• Patients with previous chronic respiratory disease
• Paraplegia with level> T8,
• Severe ICU-acquired neuromyopathy
• Patients with tracheostomy for any reason.