1. Abteilung für Anästhesie; Herzzentrum Leipzig GmbH; Struempelstrasse 39 04289 Leipzig Germany
2. Department of Anesthesiology; Regensburg University; Regensburg Germany
3. Department of Cardiothoracic Surgery; Halle-Wittenberg University; Halle Germany
4. Department of Cardiothoracic Surgery; Regensburg University; Regensburg Germany