1 Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, and Center for Clinical and Translational Research, Seattle Children's Research Institute, Seattle, WA; Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA; Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, and Center for Child Health, Behavior, and Development, Seattle Children's Research Institute, Seattle, WA.