From the Hospital Universitario de Getafe, Madrid (A.E., F.F.-V., N.D.F., I.A.); the Department of Medicine, Division of Respirology, and the Interdepartmental Division of Critical Care Medicine, University Health Network, University of Toronto, Toronto (N.D.F.); King Fahad National Guard Hospital, Riyadh, Saudi Arabia (Y.A.); Hospital Profesor Posadas, Buenos Aires (C.A.); Hospital General de Medellin, Medellin, Colombia (M.G.); the Pulmonary and Critical Care Division, Department of Medicine, New England Medical Center, Tufts University School of Medicine, Boston (S.K.E., N.S.H.); the Respiratory Intensive Care Unit, Fondazione S. Maugeri, Istituto Scientifico di Pavia, Pavia, Italy (S.N.); Hospital Universitario Sao Jose, Belo Horizonte, Brazil (M.-A.S.); Hospital de Clinicas, Caracas, Venezuela (G.D.); and the University of Texas Health Science Center, San Antonio (A.A.). Address reprint requests to Dr. Esteban at the Unidad de Cuidados Intensivos, Hospital Universitario de Getafe, Carretera de Toledo Km. 12,500, Getafe 28905, Madrid, Spain, or at aesteban@ucigetafe.com.