Ewan C Goligher1, Jesús Villar, Arthur S Slutsky. 1. Interdepartmental Division of Critical Care Medicine, University of Toronto; and, Division of Respirology, Department of Medicine, University Health Network, Toronto, ON, Canada Keenan Research Center, Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada, CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain; and Research Unit, Hospital Universitario Dr. Negrín, Las Palmas de Gran Canaria, Spain Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada; and, Keenan Research Center, Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, ON, Canada.