1. Department of Anaesthesiology; Hillerød Hospital; Hillerød; Denmark
2. Department of Anaesthesiology and Intensive Care; Sahlgrenska University Hospital; Göteborg; Sweden
3. Department of Anaesthesiology; Oulu University Hospital; Oulu; Finland
4. Department of Anaesthesia and Intensive Care Medicine; Landspitali University Hospital, University of Iceland; Reykjavik; Iceland
5. Department of Cirkulation and Medical Imaging; Norwegian University of Science and Technology; Trondheim; Norway