1. Division of Critical Care Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada T6G 2B7
2. Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada T6G 2R3
3. Division of Respirology and Respiratory Rehabilitation Services, Faculty of Medicine and Dentistry, University of Ottawa, Ottawa, ON, Canada T6G 2R3