[1] Thoraxctr Ignatius Breda, Dept Anaesthesia & Intens Care, NL-4800 RA Breda, Netherlands
[2] Vrije Univ Amsterdam, Acad Hosp, Dept Anaesthesiol, Amsterdam, Netherlands
[3] Erasmus Univ, Sch Med, Dept Epidemiol & Biostat, NL-3000 DR Rotterdam, Netherlands