University of Utah, Department of Emergency Medicine, 30 N. Mario Capecchi Dr., HELIX Bldg, Level 2 South, Salt Lake City, UT 84112, USA; University of Utah, College of Nursing, 10 S. 2000 E, Salt Lake City, UT 84112, USA; University of Utah, Department of Anesthesiology, 30 N. 1900 E., Rm 3C444, Salt Lake City, UT 84132, USA. Electronic address: