[1] Univ Arkansas Med Sci, Dept Pediat, Sect Crit Care Med, Little Rock, AR 72205 USA
[2] Cincinnati Childrens Hosp Med Ctr, Div Emergency Med, Cincinnati, OH 45229 USA
[3] Akron Childrens Hosp, Sect Crit Care Med, Dept Pediat, Akron, OH USA
[4] Univ Penn, Dept Pediat, Sect Emergency Med, Perelman Sch Med, Philadelphia, PA 19104 USA
[5] Maryland Reg Neonatal Transport Program, Baltimore, MD USA
[6] Washington Univ, Sch Med, Dept Pediat, St Louis, MO 63130 USA
[7] Med Coll Wisconsin, Dept Pediat, Sect Crit Care Med, Milwaukee, WI USA
[8] Harvard Univ, Sch Med, Brigham & Womens Hosp, Dept Newborn Med, Cambridge, MA 02138 USA