[1] Childrens Hosp Pittsburgh, Dept Anesthesiol, Pittsburgh, PA 15213 USA
[2] Glaxo Wellcome Inc, Anesthesia Clin Dev, Res Triangle Pk, NC 27709 USA
[3] Glaxo Wellcome Inc, Clin Stat Dept, Res Triangle Pk, NC 27709 USA
[4] Univ Pittsburgh, Sch Med, Dept Surg, Pittsburgh, PA USA
[5] Univ Washington, Sch Med, Dept Anesthesiol, Childrens Hosp & Reg Med Ctr, Seattle, WA 98195 USA
[6] Johns Hopkins Univ, Dept Anesthesiol, Baltimore, MD USA
[7] Johns Hopkins Univ, Dept Crit Care Med, Baltimore, MD USA
[8] Johns Hopkins Univ, Dept Pediat, Baltimore, MD USA
[9] Childrens Hosp, Dept Anesthesia, Boston, MA 02115 USA
[10] Harvard Univ, Sch Med, Dept Anaesthesia, Boston, MA USA
[11] Univ Penn, Childrens Hosp Philadelphia, Dept Anesthesiol, Philadelphia, PA 19104 USA
[12] Univ Penn, Childrens Hosp Philadelphia, Dept Pediat, Philadelphia, PA 19104 USA
[13] Stanford Univ, Dept Anesthesiol, Stanford, CA 94305 USA
[14] Stanford Univ, Dept Pediat, Stanford, CA 94305 USA
[15] Lucile S Packard Childrens Hosp, Dept Anesthesiol, Stanford, CA USA
[16] Univ Texas, Sch Med, Dept Anesthesiol, Houston, TX USA
[17] Univ Washington, Sch Med, Dept Pediat, Seattle, WA 98195 USA
[18] Harvard Univ, Sch Med, Dept Anesthesia, Boston, MA USA
[19] Childrens Hosp, Dept Cardiac Anesthesia, Boston, MA 02115 USA
[20] Univ Penn, Dept Anesthesiol, Philadelphia, PA 19104 USA
[21] Univ Pittsburgh, Dept Pediat, Pittsburgh, PA 15260 USA
[22] Univ Pittsburgh, Dept Crit Care Med, Pittsburgh, PA 15260 USA
[23] Univ Pittsburgh, Dept Anesthesiol, Pittsburgh, PA 15260 USA