1 Queensland Ambulance Service, Queensland Government Department of Health, Brisbane, Queensland, Australia. Electronic address: brendan.schultz@ambulance.qld.gov.au.
2 Queensland Ambulance Service, Queensland Government Department of Health, Brisbane, Queensland, Australia; Emergency and Trauma Centre, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia; LifeFlight Retrieval Medicine, Brisbane, Queensland, Australia.
3 Queensland Ambulance Service, Queensland Government Department of Health, Brisbane, Queensland, Australia.