[1] Sahlgrens Univ Hosp, Dept Anaesthesia & Intens Care, S-41345 Gothenburg, Sweden
[2] Univ Erlangen Nurnberg, Anasthesiol Klin, D-8520 Erlangen, Germany
[3] Univ Wales Hosp, Intens Care Unit, Cardiff CF4 4XW, S Glam, Wales
[4] Karolinska Hosp, Dept Pediat Anaesthesia & Intens Care, S-10401 Stockholm, Sweden