1. Section of Pulmonary, Critical Care, Allergy and Immunologic Diseases, Department of Internal Medicine, Wake Forest University School of Medicine , Winston Salem, NC , USA
2. Department of Anesthesiology, Wake Forest University School of Medicine , Winston Salem, NC , USA
3. Section of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Miami , Miami, FL , USA
4. Department of Internal Medicine, Section of Cardiology, Penn State College of Medicine , Hershey, PA , USA
5. Department of Internal Medicine, Section of Cardiology, Wake Forest School of Medicine , Winston-Salem, NC , USA
6. Section of Sleep Medicine, Department of Neurology, Wake Forest University School of Medicine , Winston Salem, NC , USA
7. Department of Anesthesiology, Novant and Piedmont Triad Anesthesia , Winston-Salem, NC , USA
8. Department of Neurology, Wake Forest School of Medicine , Winston-Salem, NC , USA