1. Department of Visceral Surgery and Medicine; Inselspital, Bern University Hospital, University of Bern; Switzerland
2. Department of Anaesthesiology; Inselspital, Bern University Hospital, University of Bern; Switzerland
3. Department of Clinical Research; Clinical Trial Unit; Spitalstrasse 12 4031 Basel Switzerland
4. Division of Haematology and Central Haematology Laboratory; Centre Hospitalier Universitaire Vaudois, University of Lausanne; CH 1011 Lausanne Switzerland