1. F. Edward Hebert School of Medicine; Uniformed Services University; Bethesda MD USA
2. Department of Emergency Medicine; Indiana University School of Medicine; Indianapolis IN USA
3. Department of Internal Medicine; Instituto Ramon y Cajal de Investigacion Sanitaria IRYCIS; Ramón y Cajal Hospital; Madrid Spain
4. Radiology Department; Instituto Ramón y Cajal de Investigación Sanitaria IRYCIS; Ramón y Cajal Hospital; Madrid Spain
5. Respiratory Department; Instituto Ramón y Cajal de Investigación Sanitaria IRYCIS; Ramón y Cajal Hospital; Alcala de Henares University; Madrid Spain
6. Emergency Department; Instituto Ramón y Cajal de Investigación Sanitaria IRYCIS; Ramón y Cajal Hospital; Madrid Spain
7. Divisions of Pulmonary and Critical Care Medicine; Cedars-Sinai; Los Angeles CA USA
8. Divisions of Pulmonary and Critical Care Medicine and General Medical Sciences; Washington University School of Medicine; St Louis MO USA