Mette V Hansen1, Bo Løfgren2, Kasper G Lauridsen3. 1. Research Center for Emergency Medicine, Aarhus University Hospital, Denmark. 2. Research Center for Emergency Medicine, Aarhus University Hospital, Denmark; Department of Medicine, Randers Regional Hospital, Denmark. 3. Research Center for Emergency Medicine, Aarhus University Hospital, Denmark; Emergency Department, Randers Regional Hospital, Denmark; Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, United States. Electronic address: kglerup@clin.au.dk.