1 Department of Emergency Medicine, Wexner Medical Center at The Ohio State University, and Mt. Carmel St. Ann's, Columbus, OH. Electronic address: mweinstock@ihainc.org.
2 Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA.
3 Department of Emergency Medicine, University of Southern California, Los Angeles, CA.
4 Department of Emergency Medicine, University of California-San Francisco, San Francisco, CA.