[1] Southmead Hosp, Anaesthesia & Intens Care Med, Bristol, Avon, England
[2] Royal United Hosp, Anaesthesia & Intens Care Med, Bath BA1 3NG, Avon, England
[3] Univ Bristol, Bristol, Avon, England
[4] Univ Hosp Cologne, Dept Anaesthesiol & Intens Care Med, Cologne, Germany
[5] Univ Warwick, Warwick Med Sch, Coventry CV4 7AL, W Midlands, England
[6] Heart England NHS Fdn Trust, Birmingham, W Midlands, England
[7] Johannes Gutenberg Univ Mainz, Univ Med Ctr, Dept Anesthesiol, D-55122 Mainz, Germany
[8] Necker Univ Hosp, SAMU Paris, Dept Anaesthesiol & Intens Care, Paris, France
[9] Santa Maria Angeli Hosp, Anaesthesia Intens Care & Emergency Med Serv, Pordenone, Italy
[10] Univ Cattolica Sacro Cuore, Sch Med, Dept Anaesthesiol & Intens Care, I-00168 Rome, Italy
[11] Helsinki Univ Hosp, Dept Anaesthesiol Intens Care & Pain Med, Div Intens Care, Helsinki, Finland
[12] Univ Helsinki, Helsinki, Finland
[13] Bournemouth Univ, Ctr Postgrad Med Res & Educ, Bournemouth, Dorset, England
[14] Univ Oslo, Oslo Univ Hosp, Div Emergencies & Crit Care, Dept Anaesthesiol, Oslo, Norway
[15] Univ Oslo, Inst Clin Med, Oslo, Norway
[16] Southampton Univ Hosp, NIHR Southampton Resp Biomed Res Unit, Cardiac Anaesthesia & Cardiac Intens Care, Southampton, Hants, England