1 Department of Paediatrics, Schulich School of Medicine and Dentistry at the University of Western Ontario, Children's Health Research Institute, Children's Hospital at London Health Sciences Centre, London, ON, Canada. Rod.Lim@lhsc.on.ca.
2 Department of Emergency Medicine, Stanford University School of Medicine, Palo Alto, CA, USA.
3 Department of Emergency Medicine, Michael Garron Hospital, Toronto, ON, Canada.
4 Division of Emergency Medicine and the Interdepartmental Division of Critical Care, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.