[1] Chris Hani Baragwanath Acad Hosp, Dept Emergency Med, Johannesburg, South Africa
[2] Univ Witwatersrand, Div Emergency Med, Johannesburg, South Africa
[3] Netcare Union Hosp, Dept Emergency Med, Johannesburg, South Africa
[4] Helen Joseph Hosp, Dept Emergency Med, Johannesburg, South Africa