[1] Boston Childrens Hosp, Cardiovasc & Crit Care Nursing Patient Serv, Boston, MA USA
[2] Dana Farber Canc Inst, Dept Psychosocial Oncol & Palliat Care, Boston, MA 02115 USA
[3] Boston Childrens Hosp, Dept Pediat, Boston, MA USA
[4] Boston Childrens Hosp, Dept Cardiol, 300 Longwood Ave,MS BCH3215, Boston, MA 02115 USA
[5] Harvard Med Sch, Dept Pediat, Boston, MA 02115 USA
[6] Vanderbilt, Dept Crit Care Med, Nashville, TN USA
[7] Univ Sydney, Sydney Med Sch, Sydney, NSW, Australia