1 Departments of Emergency Medicine and Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA. Electronic address: mwinters@umem.org.
2 Departments of Emergency Medicine and Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
3 Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
4 Departments of Emergency Medicine and Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.