1. Department of Biomedicine, University of Bergen, Bergen, Norway.
2. Department of Clinical Medicine K1, University of Bergen, Bergen, Norway.
3. Department of Neurosurgery, Haukeland University Hospital, Bergen, Norway.
4. Department of Anesthesia and Intensive Care, Haukeland University Hospital, Bergen, Norway.
5. Helicopter Emergency Medical Services, Bergen, Norway.
6. The Norwegian Air Ambulance Foundation, Drøbak, Norway.