1. Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt, Goethe-University Frankfurt, Theodor-Stern Kai 7, 60590 Frankfurt am Main, Germany
2. Department of Anaesthesiology, Intensive Care and Reanimation, AZ Sint Jan Brugge, 8000 Bruges, Belgium
3. Department of Anesthesiology, KULeuven, 3000 Leuven, Belgium
4. Department of Anesthesiology, UGhent, 9000 Ghent, Belgium
5. Department of Urology, University Hospital Frankfurt, Goethe-University Frankfurt, 60590 Frankfurt am Main, Germany
6. Institute of Neuroradiology, University Hospital Frankfurt, Goethe-University Frankfurt, 60528 Frankfurt am Main, Germany