Comparison of the Montreux definition with the Berlin definition for neonatal acute respiratory distress syndrome.

To compare the similarities and differences between the Montreux definition and the Berlin definition in terms of the prevalence, mortality, and complications of neonatal acute respiratory distress syndrome (ARDS). We retrospectively analyzed the data of neonates with respiratory failure treated in a neonatal intensive care unit (NICU) between 1 November 2019 and 31 December 2021. In total, 554 infants had neonatal ARDS (524 infants, Montreux definition; 549 infants, Berlin definition). The prevalence (3.1% vs. 3.3%, p = 0.438) and mortality (18.9% vs.18.0%, p = 0.716) of neonatal ARDS did not differ between the definitions. Among the 519 infants meeting both definitions, key clinical outcomes did not differ between the definitions such as ventilation duration, NICU stay, complication rates, and antibiotic use, except for nitric oxide inhalation. The Montreux and Berlin definitions identified an additional 5 and 30 patients, respectively, not captured by the other definition. The rate of inhaled nitric oxide treatment (20.0% vs. 0%, p = 0.013), air leaks (20.0% vs. 0%, p = 0.013), and invasive ventilation duration (110.00 vs.0.00 h, p = 0.002) significantly differed between the above two groups. Sixty-two patients had moderate and severe ARDS according to the Montreux and Berlin definitions, respectively. The rates of adverse outcomes (e.g., mortality, invasive ventilation time) among these patients were similar to the rates among patients with moderate ARDS according to both definitions than among patients with severe ARDS according to both definitions.  Conclusion: The prevalence, mortality, and most complications of neonatal ARDS were similar between the Montreux and Berlin definitions, which mainly differed in terms of the severity of neonatal ARDS. What is Known: • The Montreux definition was first proposed for the diagnosis of neonatal acute respiratory distress syndrome and was established in 2017. To date, the Montreux definition has not been compared with other diagnostic definitions of ARDS. What is New: • The study suggests that perinatal lung disease need not be excluded in the diagnosis of neonatal ARDS, and that the Montreux definition is more applicable to neonates, taking into account their specific physiological characteristics.