Project Abstract Decades after extracorporeal membrane oxygenation (ECMO) was first used to support children with severe pediatric acute respiratory distress syndrome (PARDS), pediatric intensivists lack both prospective studies of long-term outcomes in ECMO for PARDS and well-powered studies comparing the impact of ECMO initiation strategies on mortality and morbidity. While clinicians lack the equipoise necessary to randomize ECMO in dying children, there is uncertainty on if and when it is best to initiate ECMO to preserve survival, functioning, and quality of life. To answer the question, if and when ECMO should be initiated in children with severe PARDS, it is necessary to compare the long-term outcomes in ECMO supported children to otherwise similar children who did not receive ECMO at the same threshold if at all. An opportunity to address this question is provided by NHLBI-funded Prone and Oscillation Pediatric Clinical Trial (PROSpect) and the ECMO registry, Extracorporeal Life Support Organization (ELSO). PROSpect is a randomized clinical trial testing the impact of supine/prone positioning and conventional mechanical ventilation/high-frequency oscillatory ventilation on short and long-term clinical outcomes in 1,000 children with severe PARDS. PROSpect manages subjects with a rigorous protocol that reserves ECMO for protocol failure. The ELSO Registry includes children receiving usual care ECMO, initiated at the discretion of the intensivist. ASCEND (ARDS in Children and ECMO initiation strategies impact on Neuro-Development) will harmonize PROSpect and ELSO data collection and prospectively measure long-term functional status and quality of life in 550 children with severe PARDS from ELSO sites. ASCEND will then match children in both groups on their propensity to receive usual care ECMO. ASCEND combines real-world observational data (from ELSO) and a randomized clinical trial (from PROSpect) by matching similarly critically ill children treated under usual care ECMO or a rigorous ventilation protocol that reserves ECMO for protocol failure. Our specific aims include: Aim 1: We will test the hypotheses that one year after children receive usual care ECMO for PARDS, there will be a decline in long-term functional status and health-related quality of life as well as an increase in the proportion of children receiving respiratory support. Aim 2: We will test the hypotheses that 90-day mortality, one-year functional status, and one-year health- related quality of life are not equivalent for children with usual care ECMO (in ELSO) and PROSpect's protocolized therapies.

Project Narrative Pediatric acute respiratory distress syndrome is a life-threatening and frequent problem experienced by thousands of children each year. In severe pediatric acute respiratory distress, little evidence substantiates current supportive practices. The overall objective of this study is to compare short and long-term patient outcomes in two groups of children: one group managed with a mechanical ventilation protocol that reserves the use of extracorporeal membrane oxygenation (ECMO) until protocol failure to another group supported on ECMO per usual care.