[1] Charite Univ Med Berlin, Klin Anasthesiol Schwerpunkt Operat Intens Med, Augustenburger Pl 1, Berlin, Germany
[2] DRK Kliniken Westend, Klin Anasthesie Schmerztherapie Intens & Notfallm, Berlin, Germany
[3] Charite Univ Med Berlin, Klin Geburtsmed, Berlin, Germany
[4] Vivantes Klinikum Friedrichshain, Klin Anasthesie Intens Med Notfallmed & Schmerzth, Berlin, Germany