Altitude and Outcomes in Pediatric ARDS: A Multicenter Study

Inclusion Criteria: * Age between 1 month (corrected gestational age) and 18 years. * Admission to a pediatric intensive care unit (PICU) or facility where mechanically ventilated children are cared for. * Requirement of invasive mechanical ventilation. * Diagnosis of pediatric acute respiratory distress syndrome (PARDS) according to PALICC criteria, confirmed within 24 hours before or after endotracheal intubation. Exclusion Criteria: * Patients with active perinatal lung disease (e.g., neonatal respiratory distress syndrome, pulmonary hemorrhage, persistent pulmonary hypertension of the newborn, early bronchopulmonary dysplasia, meconium aspiration). * Patients who have received extracorporeal membrane oxygenation (ECMO) prior to or within the first 24 hours of PARDS diagnosis. * Patients with pre-established limitation of therapeutic effort (LTE) orders or palliative care directives documented before the initiation of invasive mechanical ventilation. * Readmissions to the PICU during the study period (only the first episode per patient will be included).