[1] Univ Chicago, Dept Med, Sect Emergency Med, 5841 S Maryland Ave, Chicago, IL 60637 USA
[2] Univ Texas Hlth San Antonio, Dept Emergency Med, San Antonio, TX 78229 USA
[3] Advocate Christ Med Ctr, Dept Emergency Med, Oak Lawn, IL USA
[4] Wake Forest Sch Med, Dept Emergency Med, Winston Salem, NC 27101 USA
[5] San Antonio Mil Med Ctr, Dept Emergency Mil Med, Ft Sam Houston, TX USA