Affiliation: | 1.Department of Emergency Medicine, Division of Medical Toxicology,University of Southern California,Los Angeles,USA;2.Los Angeles City Fire Department,Los Angeles,USA;3.Department of Emergency Medicine and the Leonard D. Schaeffer Center for Health Policy and Economics,University of Southern California,Los Angeles,USA;4.Department of Emergency Medicine, Division of Emergency Medical Services,University of Southern California,Los Angeles,USA |