1. Department of Anaesthesia and Critical Care, University of Wuerzburg, 97080 Wuerzburg, Germany
2. Department of Neurology, University of Wuerzburg, 97080 Wuerzburg, Germany
3. Department of Cardiothoracic and Thoracic Vascular Surgery, University of Wuerzburg, 97080 Wuerzburg, Germany