[1] Univ Hlth Network, Toronto Gen Hosp Res Inst, 200 Elizabeth St,13 EN-229, Toronto, ON M5G 2C4, Canada
[2] Univ Toronto, Temerty Fac Med, Toronto, ON, Canada
[3] Univ Toronto, Univ Hlth Network, Temerty Fac Med, Div Respirol, Toronto, ON, Canada
[4] Univ British Columbia, Dept Med, Div Resp Med, Vancouver, BC, Canada
[5] St Pauls Hosp, Ctr Heart Lung Innovat, Vancouver, BC, Canada
[6] Univ Toronto, Dept Phys Therapy, Toronto, ON, Canada
[7] Univ Hlth Network, Toronto Rehabil Inst, Interdept Div Crit Care Med, Toronto, ON, Canada