This is a multicenter, prospective, randomized, open-label study which compared two ventilation modes: spontaneous NAVA mode and spontaneous breathing with IPS mode (the latter is considered as the reference ventilatory mode) in patients admitted to the ICU for acute respiratory failure and ventilated with an endotracheal tube. NAVA mode allows to minimize patient-ventilator disharmony with acceptable tolerance and to preserve spontaneous ventilation.

Inclusion Criteria:

• Patient ventilated with endotracheal tube for more than 24 hours

• Return for at least 30 minutes to spontaneous ventilation allowing IPS with a level of pressure support <30 cm H2O;

• Level of sedation =< 4 on the Ramsay scale in the absence of medical decision to increase the level of sedation;

• Fraction of inspired oxygen (FiO 2) =< 50% with a positive end-expiratory pressure (PEEP) =< 8 cm H2O;

• Absence of administration of high-dose vasopressor therapy defined by:

  1. norepinephrine > 0.3 mcg / kg / min;
  2. dopamine > 10 mcg / kg / min;

• Estimated duration of mechanical ventilation > 48h00

Exclusion Criteria:

• Contraindication to the implementation of the NAVA endotracheal tube, ie any contraindication to the implementation of a gastric tube or to the repositioning of a tube already in place:

  1. Recent gastrointestinal suture ;
  2. Esophageal varices rupture with gastrointestinal bleeding within 4 days prior to inclusion;

• Therapeutic limitation or active treatment discontinuation;

• Pregnant women;

• Minors;

• Protected adults;

• Patient already included in the study;