There is evidence from randomized controlled trials in adult patients with Acute Respiratory Distress Syndrome (ARDS) suggesting that delivering small tidal volumes with adequate levels of Positive End-Expiratory Pressure (PEEP) and a restrictive fluid strategy could improve outcome. However, there are data and common bedside experience that individual patients may or may not respond to interventions, such as escalation of PEEP or positional changes, and there may be a role for a more personalized ventilator strategy.

This strategy could account for the unique individual morphology of lung disease, such as the amount of atelectasis and overdistension as a percentage of total lung tissue, the exact location of atelectasis, and whether positional changes or elevation of PEEP produce lung recruitment or overdistension.

Stepwise Recruitment maneuvers (SRMs) in pARDS improve oxygenation in majority of patients. SRMs should be considered for use on an individualized basis in patients with pARDS should be considered if SpO2 decreases by ≥ 5% within 5 minutes of disconnection during suction or coughing or agitation. If a recruitment maneuver is conducted, a decremental PEEP trial must be done to determine the minimum PEEP that sustains the benefits of the recruitment maneuver.

Electrical impedance tomography (EIT), a bedside monitor to describe regional lung volume changes, displays a real-time cross-sectional image of the lung. EIT is a non-invasive, non-operator dependent, bedside, radiations-free diagnostic tool, feasible in paediatric patients and repeatable. It allows to study ventilation distribution dividing lungs in four Region Of Interest (ROI), that are layers distributed in an anteroposterior direction, and shows how ventilation is distributed in the areas concerned.

EIT measures and calculates other parameters that are related not only to the distribution of ventilation, but also to the homogeneity of ventilation and the response to certain therapeutic maneuvers, such as SRMs or PEEP-application.

Aim of this study is to provide a protocolized strategy to assess optimal recruitment and PEEP setting, tailored on the patients individual response in pARDS.

Inclusion Criteria:

• Intubated and mechanically ventilated children, ageing 1 months-5 years and meeting the PALICC definition for pediatric Acute Respiratory Distress Syndrome (pARDS)
• Informed Consent signed

Exclusion Criteria: Patients with one or more of the following characteristics:

• Previous barotrauma (pneumothorax, pneumomediastinum or subcutaneous emphysema)
• Signs of intracranial hypertension
• Cyanotic congenital cardiac disease
• Dorso-lumbar pathologies or other bone pathologies associated with restrictive lung disease (such as scoliosis, kyphosis)
• Implantable devices not compatible with EIT (such as pace-makers and implantable cardioverter defibrillator)
• Controindication to positioning the esophageal catheter (surgery, esophageal stenosis)