1 Division of Pulmonary, Critical Care and Sleep Medicine, University of Washington. Seattle, Washington, USA.
2 Everest ER, Himalayan Rescue Association, Kathmandu, Nepal.
3 Division of Pulmonary and Critical Care Medicine, Intermountain Medical Center and the University of Utah, Salt Lake City, Utah, USA.
4 Division of Emergency Medicine, University of Utah, Salt Lake City, Utah, USA.
5 Division of Pulmonary and Critical Care Medicine, Sound Physicians, St. Mary's Medical Center, San Francisco, California, USA.
6 Medical Service, VA Puget Sound Health Care System, Seattle, Washington, USA.
7 Altitude Research Center, Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.