1 From the Keenan Research Center at the Li Ka Shing Knowledge Institute, St. Michael's Hospital (A.S.S., J.V.), and the Departments of Medicine, Surgery, and Biomedical Engineering, University of Toronto (A.S.S.) - both in Toronto; and CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, and the Multidisciplinary Organ Dysfunction Evaluation Research Network, Research Unit, Hospital Universitario Dr. Negrín, Las Palmas de Gran Canaria - both in Spain (J.V.).