[1] Univ Hosp Frankfurt, Clin Anaesthesiol Care Med & Pain Therapy, D-60590 Frankfurt, Germany
[2] Univ Hosp Rostock, Clin Anaesthesiol & Intens Care Med, Rostock, Germany
[3] Univ Hosp Aachen, Dept Anaesthesiol, Aachen, Germany
[4] Univ Hosp Luebeck, Dept Anaesthesiol, Lubeck, Germany
[5] Univ Hosp Bonn, Dept Anaesthesiol & Intens Care Med, Bonn, Germany
[6] Univ Hosp Gottingen, Dept Anaesthesiol & Intens Care Med, Gottingen, Germany
[7] Univ Hosp Duesseldorf, Dept Anaesthesiol & Intens Care Med, Dusseldorf, Germany
[8] Univ Hosp Magdeburg, Dept Anaesthesiol, Magdeburg, Germany
[9] Univ Hosp Wuerzburg, Dept Anaesthesiol, Wurzburg, Germany
[10] Charite, Dept Anaesthesiol & Intens Care Med, D-13353 Berlin, Germany
[11] Univ Giessen, Dept Cardiovasc Surg, D-35390 Giessen, Germany
[12] Johannes Gutenberg Univ Mainz, Med Ctr, Dept Anesthesiol, Mainz, Germany
[13] Univ Dusseldorf, Dept Anesthesiol, Dusseldorf, Germany
[14] Jena Univ Hosp, Dept Anesthesiol & Intens Care Med, Jena, Germany