1 Department of Emergency Medicine and Pre-Hospital Services, St. Olav's University Hospital, Prinsesse Kristinas Gate 3, 7030, Trondheim, Norway. Jostein.brede@norskluftambulanse.no.
2 Department of Research and Development, Norwegian Air Ambulance Foundation, Oslo, Norway. Jostein.brede@norskluftambulanse.no.
3 Department of Anesthesiology and Intensive Care Medicine, St. Olav's University Hospital, Trondheim, Norway. Jostein.brede@norskluftambulanse.no.
4 Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway. Jostein.brede@norskluftambulanse.no.
5 Department of Radiology and Nuclear Medicine, St. Olav's University Hospital, Trondheim, Norway.
6 Department of Research and Development, Norwegian Air Ambulance Foundation, Oslo, Norway.
7 Division of Prehospital Services, Air Ambulance Department, Oslo University Hospital, Oslo, Norway.
8 Faculty of Health Sciences, University of Stavanger, Stavanger, Norway.