[1] Ruhr Univ Bochum, Univ Klinikum, Johannes Wesling Klinikum Minden, Univ Klin Anasthesiol Intens & Notfallmed, Minden, Germany
[2] Univ Med Rostock, Klin & Poliklin Anasthesiol Intens Med & Schmerzth, Rostock, Germany
[3] Ruhr Univ Bochum, Univ Klinikum, Johannes Wesling Klinikum Minden, Univ Klin Anasthesiol Intens & Notfallmed, Hans Nolte Str 1, D-32429 Minden, Germany
[4] Univ Med Rostock, Klin & Poliklin Anasthesiol Intens Med & Schmerzth, Schillingallee 35, D-18057 Rostock, Germany