[1] Kuopio Univ Hosp, Dept Anaesthesia & Intens Care, POB 100, FI-70029 Kuopio, Finland
[2] Univ Eastern Finland, Sch Med, Kuopio, Finland
[3] Kuopio Univ Hosp, Dept Med, Kuopio, Finland
[4] Turku Univ Hosp, Lab Div, Turku, Finland
[5] Univ Turku, Fac Med, Dept Clin Chem, Turku, Finland