[1] Friedrich Alexander Univ Erlangen Nurnberg, Univ Hosp Erlangen, Dept Anesthesiol, D-91054 Erlangen, Germany
[2] Outcomes Res Consortium, Houston, TX 77005 USA
[3] Univ Amsterdam, Med Ctr, Dept Intens Care, Amsterdam, Netherlands
[4] Med Univ Vienna, Dept Anesthesiol Intens Care Med & Pain Med, Div Cardiac Thorac Vasc Anesthesia & Intens Care M, Vienna, Austria
[5] Saarland Univ, Med Ctr, Dept Anesthesiol Intens Care & Pain Therapy, Homburg, Saarland, Germany
[6] Saarland Univ, Fac Med, Homburg, Saarland, Germany