1. Department of Emergency Medicine, Holbaek Hospital, University of Copenhagen, Holbaek, Denmark
2. Department of Anaesthesia, Centre of Head and Orthopaedics, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
3. Department of Emergency Medicine, North Denmark Regional Hospital, Hjoerring, Denmark
4. Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark