[1] Univ Calif San Francisco, Dept Emergency Med, San Francisco, CA 94143 USA
[2] Univ Southern Calif, Keck Sch Med, Los Angeles, CA 90007 USA
[3] Los Angeles Cty Univ Southern Calif, Med Ctr, Los Angeles, CA USA
[4] Texas A&M Coll Med, Dept Emergency Med, Temple, TX USA
[5] Baylor Scott & White Hlth, Dept Emergency Med, Temple, TX USA
[6] Louisiana State Univ, Sch Med, Dept Med, Sect Emergency Med,Sect Pulm & Crit Care, New Orleans, LA USA
[7] Amer Univ Beirut, Med Ctr, Dept Emergency Med, POB 11-0236, Beirut 11072020, Lebanon
[8] Univ Calif Irvine, Dept Emergency Med, Irvine, CA USA