T Dehli1,2, O Uleberg3,4, T Wisborg1,5. 1. Anaesthesia and Critical Care Research Group, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway. 2. Department of Gastrointestinal Surgery, University Hospital North Norway Tromsø, Tromsø, Norway. 3. Department of Emergency Medicine and Pre-hospital Services, St. Olav's University Hospital, Trondheim, Norway. 4. Department of Research and Development, Norwegian Air Ambulance Foundation, Drøbak, Norway. 5. Norwegian National Advisory Unit on Trauma, Division of Emergencies and Critical Care, Oslo University Hospital Ullevål, Oslo, Norway.