[1] Harvard Med Sch, Dept Emergency Med, Boston, MA USA
[2] Massachusetts Gen Hosp, Dept Emergency Med, Boston, MA 02114 USA
[3] Brigham & Womens Hosp, Dept Emergency Med, 75 Francis St, Boston, MA 02115 USA
[4] Massachusetts Gen Hosp, Dept Pharm, Boston, MA 02114 USA
[5] Massachusetts Gen Hosp, Dept Radiol, Boston, MA USA
[6] Univ Southern Calif, Keck Sch Med, Dept Emergency Med, Los Angeles, CA 90033 USA