[1] George Washington Univ, Sch Med & Hlth Sci, Dept Emergency Med, Washington, DC 20037 USA
[2] Univ Maryland, Sch Med, Dept Emergency Med, Baltimore, MD 21201 USA
[3] Univ Maryland, R Adams Cowley Shock Trauma Ctr, Program Trauma, Sch Med, Baltimore, MD 21201 USA
[4] George Washington Univ, Ctr Trauma & Crit Care, Dept Surg, Sch Med & Hlth Sci, Washington, DC 20037 USA