1. Department of Pulmonary and Critical Care Northeast Georgia Health System Gainesville Georgia USA
2. Department of Internal Medicine Northeast Georgia Health System Gainesville Georgia USA
3. Division of Cardiovascular Critical Care, Department of Cardiovascular and Thoracic surgery West Virginia University West Virginia USA
4. IPC Global Alpharetta Georgia USA
5. Division of Pulmonary and Critical Care Medical College of Wisconsin Milwaukee Wisconsin USA
6. Division of Hematology/Oncology, Georgia Cancer Center Augusta University Augusta Georgia USA