1. Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark
2. Departmet of Clinical Medicine, Aarhus University, Aarhus, Denmark
3. Department of Anaesthesia, Centre of Head and Orthopaedics, Copenhagen University Hospital, Rigshospitalet, Denmark
4. Department of Anesthesiology and Surgery, Aarhus University Hospital, Aarhus