Trial Evaluating the Interest of Noninvasive Ventilation in NAVA Mode in Respiratory Decompensations Children With Infantile Spinal Muscular Atrophy Type II

"The study has 3 phases:~1. Phase 1:~ The patient is connected to the SERVOi® ventilator in classic VNI mode, which is parameterized according to the patient's needs and then maintained for 30min for measurements.~2. Phase 2:~ Switch to NAVA mode (1h).~ * Definition of NAVA parameters: The positive expiratory pressure will not be modified. The NAVA level (the proportionality factor that converts the EADi (microV) to the pressure level in cmH2O was first adjusted according to the actual assisted pressure in the patient in the normal VNI mode.~ * NAVA period: The ventilatory pressure, as well as the EADI is recorded continuously for 30min after a NAVA adaptation period of about 30min.~3. Phase 3:~The patient returns to classic VNI mode with Phase 1 ventilatory settings for a 30 minute recording."