De Luca D, Piastra M, Chidini G, Tissieres P, Calderini E, Essouri S, Medina Villanueva A, Vivanco Allende A, Pons-Odena M, Perez-Baena L, Hermon M, Tridente A, Conti G, Antonelli M, and Kneyber M
Purpose: A new acute respiratory distress syndrome (ARDS) definition has been recently issued: the so-called Berlin definition (BD) has some characteristics that could make it suitable for pediatrics. The European Society for Pediatric Neonatal Intensive Care (ESPNIC) Respiratory Section started a project to evaluate BD validity in early childhood. A secondary aim was reaching a consensus on clinical tools (risk factors list and illustrative radiographs) to help the application of BD., Methods: This was an international, multicenter, retrospective study enrolling 221 children [aged greater than 30 days and less than 18 months; median age 6 (range 2-13) months], admitted to seven European pediatric intensive care units (PICU) with acute lung injury (ALI) or ARDS diagnosed with the earlier definition., Results: Patients were categorized according to the two definitions, as follows: ALI, 36; ARDS, 185 (for the American-European Consensus Conference (AECC) definition); mild, 36; moderate, 97; severe ARDS, 88 (for BD). Mortality (13.9 % for mild ARDS; 11.3 % for moderate ARDS; 25 % for severe ARDS, p = 0.04) and the composite outcome extracorporeal membrane oxygenation (ECMO)/mortality (13.9 % for mild ARDS; 11.3 % for moderate ARDS; 28.4 % for severe ARDS, p < 0.01) were different across the BD classes, whereas they were similar using the previous definition. Mortality [HR 2.7 (95 % CI 1.1-7.1)] and ECMO/mortality [HR 3 (95 % CI 1.1-7.9)] were increased only for the severe ARDS class and remained significant after adjustment for confounding factors. PICU stay was not different across severity classes, irrespective of the definition used. There was significant concordance between raters evaluating radiographs [ICC 0.6 (95 % CI 0.2-0.8)] and risk factors [ICC 0.92 (95 % CI 0.8-0.97)]., Conclusions: BD validity for children is similar to that already reported in adults and mainly due to the introduction of a "severe ARDS" category. We provided clinical tools to use BD for clinical practice, research, and health services planning in pediatric critical care.