Jennifer Jamieson1, Rob Mitchell2, James Le Fevre3, Andrew Perry4. 1. Emergency and Trauma Centre, The Alfred Hospital, Melbourne, Victoria, Australia. 2. Department of Emergency Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia. 3. Adult Emergency Department, Auckland City Hospital, Auckland, New Zealand. 4. MedSTAR Emergency Medical Retrieval Service, South Australian Ambulance Service, Adelaide, South Australia, Australia.