1. Department of Emergency Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
2. Emergency Health Services Nova Scotia, Halifax, Nova Scotia, Canada.
3. Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada.
4. IWK Health Center, Halifax, Nova Scotia, Canada.
5. Atlantic Offshore Medical Services Ltd., St. John's, Newfoundland and Labrador, Canada.