1. Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado School of Medicine, Aurora, Colorado;
2. Department of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, Minnesota;
3. Division of Pulmonary, Critical Care, and Sleep Medicine, University of Kansas School of Medicine, Kansas City, Kansas; and
4. Division of Pulmonary and Critical Care Medicine, University of Maryland School of Medicine, Baltimore, Maryland