[1] Univ Calif Davis, Sch Med, Dept Emergency Med, Sacramento, CA 95817 USA
[2] Univ Calif Davis, Sch Med, Dept Surg, Sacramento, CA 95817 USA
[3] Univ Calif Davis, Sch Med, Dept Pediat, Sacramento, CA 95817 USA
[4] Childrens Hosp Boston, Div Emergency Med, Boston, MA USA
[5] Univ Utah, Dept Pediat, Salt Lake City, UT USA
[6] Univ Maryland, Dept Pediat, Baltimore, MD 21201 USA
[7] Holy Cross Hosp, Silver Spring Emergency Phys, Silver Spring, MD USA
[8] Helen DeVos Childrens Hosp, Grand Rapids, MI USA
[9] Childrens Natl Med Ctr, Emergency Div, Washington, DC USA