1. Department of Anesthesiology, Ludwig-Maximilians-University of Munich, Munich, Germany
2. Department of Anesthesiology, Ruprecht-Karls-University, Heidelberg, Germany
3. Institute of Emergency Medicine and Management in Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
4. Department of Urology, Ludwig-Maximilians-University of Munich, Munich, Germany
5. Institute of Medical Biometry and Epidemiology, Philipps-University of Marburg, Marburg, Germany
6. Department of Anesthesiology, Ruhr-University of Bochum, Bad Oeynhausen, Germany