[1] Harvard Univ, Sch Med, Boston Childrens Hosp, Div Crit Care Med,Dept Anesthesiol Perioperat & P, Boston, MA USA
[2] Childrens Med Ctr, Dallas, TX 75235 USA
[3] Univ Hosp Geneva, Neonatal & Pediat Intens Care Unit, Dept Pediat, Geneva, Switzerland
[4] Czech Tech Univ, Kladno, Czech Republic
[5] Univ Med Ctr Utrecht, Wilhelmina Childrens Hosp, Dept Pediat Intens Care, Utrecht, Netherlands
[6] Queen Paola Childrens Hosp, Pediat Intens Care, Antwerp, Belgium
[7] Vrije Univ Amsterdam Med Ctr, Div Pediat Intens Care, Dept Pediat, Amsterdam, Netherlands
[8] Hosp Sick Children, Toronto, ON M5G 1X8, Canada