1. Dept. of Anesthesiology and Intensive Care Medicine, University Hospital, Tübingen, Germany
2. Dept. of Urology, Caritas Hospital, Bad Mergentheim, Germany
3. Dept. of Anesthesiology and Intensive Care Medicine, MediClin Herzzentrum, Lahr/Baden, Germany
4. Dept. of Anesthesiology and Intensive Care Medicine, Klinikum Bayreuth, Germany
5. University Heart Center Freiburg / Bad Krozingen, Faculty of Medicine, University of Freiburg, Germany
6. Institute for Clinical Epidemiology and Applied Biometry, University of Tübingen, Germany
7. Dept. of Thoracic, Cardiac and Vascular Surgery, University Hospital, Tübingen Germany
8. Dept. of Anesthesiology, Intensive Care, Emergency, and Pain Medicine, St. Elisabethen Klinikum, Ravensburg, Germany