1. Division of Pulmonary, Critical Care, and Sleep Medicine, University of Nebraska Medical Center, Omaha, Nebraska;
2. Section of Pulmonary, Critical Care and Sleep Medicine, Veterans Affairs Puget Sound Healthcare System, Seattle, Washington;
3. Division of Pulmonary, Critical Care, and Sleep Medicine, University of Washington, Seattle, Washington;
4. Division of Pulmonary and Critical Care, Northwestern University, Chicago, Illinois;
5. Section of Pulmonary Diseases, Critical Care, and Environmental Medicine, Tulane University School of Medicine, New Orleans, Louisiana;
6. Division of Pulmonary Critical Care Medicine, Mayo Clinic, Rochester, Minnesota;
7. Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Pennsylvania State University College of Medicine, Hershey, Pennsylvania; and
8. Division of Pulmonary, Critical Care, and Sleep Medicine, University of Kansas Medical Center, Kansas City, Kansas