1 Oslo University Hospital, Division of Emergencies and Critical Care, Department of Pain Management and Research, PB 4956 Nydalen, 0424 Oslo, Norway.
2 University of Oslo, Faculty of Medicine, Oslo, Norway.
3 Oslo University Hospital, Division of Emergencies and Critical Care, Department of Anaesthesiology, Oslo, Norway, Phone: +47 23073691.
4 Oslo University Hospital, Division of Emergencies and Critical Care, Department of Anaesthesiology, Oslo, Norway.
5 Department of Anaesthesiology, Aarhus University Hospital, Aarhus, Denmark.
6 Department of Anaesthesiology, MRC Oulu, University of Oulu, and Oulu University Hospital, Oulu, Finland.
7 Department of Anaesthesia and Intensive Care, University Hospital Landspitalinn, Reykjavik, Iceland.
8 Institute of Clinical Sciences, University of Lund, and Department of Paediatric Anaesthesiology and Intensive Care, SUS Lund University Hospital, Lund, Sweden.
9 Section for Anaesthesiology and Intensive Care Medicine, Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden.