H B Ammundsen1, M K Sørensen2, M R Gätke2. 1. Department of Anaesthesiology, University of Copenhagen, Herlev Hospital, Herlev Ringvej 75, 2730 Herlev, Denmark henriette_ammundsen@dadlnet.dk. 2. Department of Anaesthesiology, University of Copenhagen, Herlev Hospital, Herlev Ringvej 75, 2730 Herlev, Denmark.