[1] Queens Univ, Dept Emergency Med, Kingston, ON K7L 2V7, Canada
[2] Queens Univ, Kingston, ON K7L 2V7, Canada
[3] Queens Univ, Dept Med, Kingston, ON K7L 2V7, Canada
[4] Univ Toronto, Dept Med, Div Emergency Med, Toronto, ON, Canada
[5] Univ Toronto, Interdept Div Crit Care, Toronto, ON, Canada
[6] Queens Univ, Dept Med, Div Neurol, Kingston, ON K7L 2V7, Canada
[7] Univ Alberta, Div Crit Care Med, Edmonton, AB, Canada
[8] Univ Alberta, Dept Emergency Med, Edmonton, AB, Canada
[9] Univ Toronto, Dept Med, Toronto, ON, Canada
[10] Univ Toronto, Inst Hlth Policy Management & Evaluat, Toronto, ON, Canada
[11] Dalhousie Univ, Dept Emergency Med, Dept Crit Care Med, Halifax, NS, Canada
[12] Univ Alberta Hosp, Dept Anesthesiol, Edmonton, AB T6G 2B7, Canada
[13] Univ Alberta Hosp, Dept Crit Care, Edmonton, AB T6G 2B7, Canada
[14] Univ Toronto, Interdept Div Crit Care Med, Toronto, ON, Canada
[15] Sunnybrook Hlth Sci Ctr, Dept Crit Care Med, Toronto, ON M4N 3M5, Canada
[16] Sunnybrook Hlth Sci Ctr, Sunnybrook Res Inst, Toronto, ON M4N 3M5, Canada
[17] St Michaels Hosp, Li Ka Shing Knowledge Inst, Keenan Res Ctr, Crit Care Dept, Toronto, ON M5B 1W8, Canada
[18] McMaster Univ, Hamilton, ON, Canada
[19] Hamilton Hlth Sci, Hamilton, ON, Canada
[20] McMaster Univ, Dept Neurol & Crit Care Med, Hamilton, ON, Canada
[21] St Michaels, Li Ka Shing Knowledge Inst, Rescu, Toronto, ON, Canada