1. Clinical Evaluation Research Unit, Kingston General Hospital, Kingston, Ontario, Canada
2. Department of Perioperative Medicine and Intensive Care, Karolinska University Hospital, Huddinge, Sweden
3. Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
4. Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
5. Division of Pulmonary and Critical Care Medicine, University of Vermont, Burlington, Vermont, USA