Post-extubation High-flow Nasal Oxygen for Preventing Extubation Failure

Patients intubated due to acute respiratory failure have a high risk of infectious complications, airway injuries and multiple organic failure, so performing a successful extubation from mechanical ventilation is key. Between 10 and 20% of patients develop extubation failure, which is related to an increased in-hospital death rate, infections, higher costs and longer hospital stays. High-flow nasal oxygen therapy delivers heated, humidified air at flows up to 60L/min, and an oxygen concentration close to 100%, providing a fresh air reservoir at the naseo-pharyngeal level, evening out the peak inspiratory flow rate of the patient, improving air conductance, promoting secretion management, increasing end-expiratory lung volume, and applying a positive end-expiratory pressure. Such effects result in decreased breathing work, dyspnea relief, improved use tolerance, increased oxygenation, and lower fraction of inspired oxygen in patients with hypoxemic respiratory failure. High-flow oxygen therapy has recently been described to decrease extubation failure in a group of patients classified with low failure risk, in comparison to Venturi mask, and it was not inferior to non-invasive mechanical ventilation in high risk patients. However, it is worth pointing out that a large percentage of the patients included in such studies did not develop acute respiratory failure primarily. Given the beneficial effects described above, the investigators hypothesize that high-flow nasal oxygen therapy decreases the risk of extubation failure in a group of patients that required invasive mechanical ventilation due to primary acute hypoxemic respiratory failure.