Patient-ventilator Asynchrony During Mechanical Non-Invasive Assisted-ventilation in Pediatric Patients (NavPed-NI)

Two sessions will be recorded, one in PSV, one with NAVA, delivered in a random order after being sure the infant is calm and comfortable, according to his parents and/or the nurse in charge. Criteria for initiating non-invasive ventilation will follow the usual practice guidelines of the unit. Ventilation parameters in Non-invasive-Pressure Support will be adjusted by the clinician in charge of the patient, as usual based on clinical observation. Investigators will not interfere with ventilator settings. Ventilation will be applied via an endotracheal tube, uncuffed for the majority (if infant \< 5 years), according to commonly applied guidelines in this unit. One 15 minutes session will be recorded, after being sure the infant is calm and comfortable according to the parents and/or the nurse in charge. Then the clinician in charge of the patient will modify the ETS, first decreasing it of 15% (absolute value)below the initial set value, and will be recorded the following 5 minutes after stabilization and secondly increasing it of 15% (absolute value)above the initial set value, and will be recorded the following 5 minutes after stabilization. NAVA will be set to deliver initially the same peak pressure (comparable level of assist) than during the initial PS period. Same PEEP will be delivered in both modes. This is possible with a pre-visualization window, allowing adjustments before switching to the NAVA mode. Nava non-invasive-ventilation will be recorded during 20 minutes. The 2 sessions, Pressure support and Nava, will be recorded consecutively.