Non-Invasive Ventilation Versus High-flow Nasal Oxygen in Intensive Care Units

In intensive care units (ICUs), around 20% of patients experience respiratory failure after planned extubation. Nearly 40-50% of them eventually require reintubation with subsequently high mortality rates reaching 30-40%. NIV used as rescue therapy to treat post-extubation respiratory failure could increase the risk of death. However, NIV may avoid reintubation in a number of cases, and recent large-scale clinical trials on extubation have shown that around 40 to 50% of patients with post-extubation respiratory failure are actually treated with NIV. Whereas high-flow nasal oxygen has never been specifically studied for management of post-extubation respiratory failure, this respiratory support could also in this setting constitute an alternative to standard oxygen or NIV. Given the best noninvasive respiratory support strategy in patients with post-extubation respiratory failure remains unknown, we have decided to assess whether NIV alternating with high-flow nasal oxygen as compared to high-flow nasal oxygen alone may decrease mortality of patients in ICUs with post-extubation respiratory failure.

Inclusion Criteria:Duration of invasive mechanical ventilation of more than 24h in the ICU before extubation.Post-extubation respiratory failure occurring within the first 7 days after extubation (see criteria below). As in several previous studies, post-extubation respiratory failure will be defined by the presence of the 2 following criteria combining a clinical criterion and a blood gas criterion:Clinical criterion persisting for at least 30 minutes: a respiratory rate exceeding 25 breaths per minute or clinical signs of respiratory distress with increased accessory muscle activity.Blood gas criterion: Hypoxemia defined as PaO2/FiO2 ratio below 150 mm Hg or respiratory acidosis defined as pH below 7.35 units and PaCO2 above 45 mm Hg. For patients under standard oxygen, FiO2 will calculated according to the following formula: FiO2 = 0.21 + 0.03 x (oxygen flow L/min).Informed consent from the relatives or the patient himself, or emergency inclusion procedure in case of inability of patient or proxy to give consent.Exclusion Criteria:NIV at homeICU admission for peripheral neuromuscular disease type Guillain-Barré syndrome or myasthenia gravis.Upper airway obstruction as main reason for post-extubation respiratory failureUrgent need for reintubation (respiratory or cardiac arrest, respiratory pauses with loss of consciousness or gasping for air, or severe hypoxemia defined as SpO2 lower than 90% despite maximal oxygen support)Altered consciousness (Glasgow coma scale < 12)Unplanned extubation (accidental or self-extubation)Do-not-reintubate order at time of respiratory failurePatient previously included in the studyPeople under protection (minors, persons deprived of liberty by a judicial or administrative decision, adults under law protection)Patient not affiliated to health care system.