1. Department of Internal Medicine III, Oncology, Hematology, Rheumatology and Clinical Immunology, University Hospital of Bonn, 53113 Bonn, Germany
2. Department of Obstetrics and Gynecology, University Hospital of Bonn, 53113 Bonn, Germany
3. Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Bonn, 53113 Bonn, Germany
4. Institute for Medical Biometry, Informatics and Epidemiology, Medical Faculty, University of Bonn, 53113 Bonn, Germany
5. Department of Intensive Care Medicine, DRK Hospital Kirchen, 57548 Kirchen, Germany
6. Department of Anaesthesiology Intensive Care Medicine and Pain Therapy, University Medical Centre Rostock, 18057 Rostock, Germany