[1] Univ Hosp Bristol & Weston, Gen Intens Care Unit A600, Bristol, England
[2] North Bristol NHS Trust, Res & Dev Dept, Bristol, England
[3] Queens Univ Belfast, Wellcome Wolfson Inst Expt Med, Belfast, North Ireland
[4] Univ Plymouth, Fac Hlth, Sch Nursing & Midwifery, Plymouth, England
[5] Curtin Univ, Curtin Sch Nursing, Perth, Australia
[6] Fudan Univ, Zhongshan Hosp, Shanghai, Peoples R China