Non-invasive ventilation (NIV, delivered via a mask or cannulas) permits to reduce the need for tracheal intubation in infants who needs a ventilatory support. NIV can be delivered with nasal CPAP (continuous positive airway pressure) or NIPPV (nasal intermittent positive pressure ventilation). The synchronization of the respiratory support according to the patient's demand is very difficult to obtain in infants with the conventional ventilatory modes. In all these ventilatory modes, the end-expiratory pressure (PEEP) is fixed and set by the clinician. However, since infants are prone to alveolar collapse and must compensate for a non-compliant chest wall, an active and ongoing management of PEEP is very important to prevent the lung de-recruitment.

A new respiratory support system (NeuroPAP) has been developed to address these issues of synchronization and control of PEEP. This new system uses diaphragmatic tonic activity (Edi) that reflects the patient's efforts to increase lung recruitment and therefore it continuously controls the delivery of assist continuously both during inspiration (like NAVA) and during expiration, allowing a unique neural control of PEEP.

A new device, the NeuroBOX, permits to deliver NIV with NeuroPAP, CPAP, or NIPPV, and also to serve as a cardio-respiratory monitor, tracking and displaying cardiac and respiratory signals, trends, and cardio-vascular events.

The two main objectives of this study are: 1- To evaluate the clinical impact of NeuroPAP in infants with high tonic Edi; 2- To characterize the cardio-respiratory pattern and its relationship with cerebral perfusion of infants with noninvasive support, using the monitoring capacity of the NeuroBOX.

The investigators expect that NeuroPAP will permit to improve the efficiency of NIV in infants, through the better synchronization and the personalization of the expiratory pressure level in response to the patient needs.

This study will be conducted in two subgroups of patients at high risk of elevated tonic Edi and of cardio-respiratory events: a subgroup of premature infants and a subgroup of infants with bronchiolitis.

Inclusion Criteria:

For premature infants group:

• Preterm infants born at a gestational age (GA) between 25 weeks (+0/7 days) and 34 weeks inclusively
• With post-birth age : > 2 days (for birth GA >28 weeks) or > 6 days (GA <28weeks) and < 4 months
• on non-invasive support, including CPAP, NIPPV, or NAVA, with settings in the following range : Maximal inspiratory pressure (total, including PEEP) ≤ 20 cmH2O, and PEEP between 4 and 9 cmH2O, and FiO2 < 50%

For bronchiolitis group:

• Infants with a weight < 5kg and a clinical diagnosis of bronchiolitis.

• on non-invasive support, including CPAP, NIPPV, or NAVA with settings in the range: Delivered inspiratory pressure (total, including PEEP) ≤ 20 cmH2O and PEEP: 5-9 cmH2O, and FiO2 <60 %

• With persisting respiratory failure: presence of at least one of the following criteria:

  • Respiratory rate > 50 /min
  • Symptoms of respiratory distress: mWCAS > 3
  • FiO2 > 30% -
  • Inspiratory Edi consistently > 15 µV

Exclusion Criteria: for both premature infants and bronchiolitis groups

• Suspected or proven pneumothorax;
• Patient on high-flow nasal cannula or on NAVA;
• Contra-indications to the placement of a new nasogastric tube (e.g. severe coagulation disorder, malformation or recent surgery in cervical, nasopharyngeal or esophageal regions);
• Hemodynamic instability requiring inotropes;
• Severe respiratory instability requiring imminent intubation according to the attending physician, or FiO2 > 50% to achieve a SpO2>90%, or PaCO2 > 75 mmHg on the last blood gas;
• Patient for whom a limitation of life support treatments is discussed or decided;
• Refusal by the treating physician;
• Refusal by the parents or legal guardians.