[1] Royal Perth Hosp, Emergency Dept, POB 2213, Perth, WA 6000, Australia
[2] Small Anim Specialist Hosp, Emergency & Crit Care, Tuggerah, NSW, Australia
[3] Murdoch Univ, Coll Sci Hlth Engn & Educ, Murdoch, WA, Australia
[4] Harry Perkins Inst Med Res, Ctr Clin Res Emergency Med, Perth, WA, Australia
[5] Univ Western Australia, Med Sch, Perth, WA, Australia