M V Madsen1, S Scheppan2, E Mørk1,2, P Kissmeyer3, J Rosenberg4, M R Gätke1. 1. Department of Anesthesiology, Herlev and Gentofte Hospital, University of Copenhagen, Denmark. 2. Department of Anesthesiology, Aarhus University Hospital, Nørrebrogade, Denmark. 3. Department of Gastrointestinal Surgery, Aarhus University Hospital, Nørrebrogade, Denmark. 4. Department of Surgery, Herlev and Gentofte Hospital, University of Copenhagen, Denmark.