Diaphragmatic Work During HFNC and CPAP Support

The goal of this randomised controlled, cross-over clinical trial is to compare High Flow Nasal Cannulas (HFNC) and Continuous Positive Airways Pressure (CPAP) in neonates over 34 weeks' amenorrhoea (SA) up to children weighing less than 20 kg with respiratory failure. The main question it aims to answer is the non-inferiority of high flows of high-flow nasal cannula compared with CPAP by analysis of diaphragmatic contraction (EAdi (Electrical activity of diaphragm)). Participants with respiratory failure and need of non invasive ventilation and nasogastric tube will receive 4 different increasing flows of HFNC and Positive End-Expiratory Pressure of 7 cmH2O with CPAP during 30 minutes for each flow rate and CPAP. The electrical activity of diaphragm and clinical data of the patient upon each flow and support will be collected. According to the cross-over procedure, the patients will change groups (increasing flows of HFNC or CPAP) in order to perform the remaining analysis.