[1] Univ Regensburg, Inst Epidemiol & Prevent Med, Med Sociol, Dr Gessler Str 17, D-93051 Regensburg, Germany
[2] Univ Hosp Regensburg, Dept Anesthesia, Operat Intens Care, Regensburg, Germany
[3] Georg August Univ Gottingen, Univ Med, Dept Anesthesiol Emergency & Intens Care Med, Gottingen, Germany
[4] Charite, Campus Virchow Klinikum, Dept Anesthesia & Operat Intens Care, Berlin, Germany
[5] Charite, Campus Charite Mitte, Berlin, Germany
[6] Univ Med Ctr, Dept Intens Care Med, Hamburg, Germany
[7] Univ Hosp Frankfurt, Dept Anesthesiol Intens Care Med & Pain Therapy, Frankfurt, Germany
[8] Univ Hosp Marburg, Dept Anesthesiol & Operat Intens Care, Marburg, Germany
[9] Univ Hosp Munster, Dept Anesthesiol & Operat Intens Care, Munster, Germany
[10] Evangel Krankenhaus, Dept Anesthesiol & Intens Care, Bielefeld, Germany
[11] Hannover Med Sch, Dept Resp Med, Hannover, Germany
[12] Univ Hosp Bonn, Dept Anesthesiol & Operat Intens Care, Bonn, Germany