1. The Norwegian Air Ambulance Foundation; Oslo Norway
2. Institute of Basic Medical Sciences; University of Oslo; Oslo Norway
3. Department of Anesthesiology; Østfold Hospital; Kalnes Norway
4. Department of Neurology; Østfold Hospital; Kalnes Norway
5. Department of Neurology; Oslo University Hospital; Oslo Norway
6. Department of Health Science; University of Stavanger; Stavanger Norway