1. Department of Emergency Medicine, University of Texas at Southwestern Medical Center, Dallas, Texas, USA.
2. Department of Emergency Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA.
3. Department of Critical Care, Sharp Memorial Hospital, San Diego, California, USA.
4. Department of Internal Medicine, Division of Infectious Disease, VA North Texas Health Care System and University of Texas Southwestern Medical Center, Dallas, Texas, USA.
5. Department of Anesthesiology, University of Texas at Southwestern Medical Center, Dallas, Texas, USA.
6. Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri, USA.