1. From Children's Hospital of Pittsburgh, Department of Pediatrics, Division of Pediatric Emergency Medicine;
2. University of Pittsburgh, Departments of Anesthesia/Critical Care Medicine and the Safar Center for Resuscitation Research;
3. Mercy Hospital, Department of Pediatrics; and
4. Geriatric Research Educational and Clinical Center, VA Pittsburgh Health System and the University of Pittsburgh, Department of Neurology, Pittsburgh, Pennsylvania.