The Acute Respiratory Distress Syndrome (ARDS) study will be opening soon in the CPCCRN network. The primary purpose of this important new study is to determine the relationship between clinical and biological markers and their effects on the course of pediatric ARDS, mortality, and long-term morbidity of hospitalized children with acute respiratory distress syndrome. This study plans to enroll 300 subjects over approximately 3 years across 8 network sites. Enrollment is expected to begin in early 2019.