1. Department of Anesthesiology, Division of Emergencies and Critical Care Medicine, Oslo University Hospital, Rikshospitalet, Postboks 4950 Nydalen, Oslo N-0424 , Norway
2. Faculty of Medicine, Oslo University Hospital , Oslo , Norway
3. Department of Obstetrics, Division of Obstetrics and Gynecology, Oslo University Hospital, Rikshospitalet, Oslo N-0424, Norway
4. Department of Cardiology, Division of Heart, Lung, and Vessel diseases, Oslo University Hospital, Rikshospitalet, Oslo N-0424, Norway
5. Institute of Clinical Medicine, University of Oslo , Oslo , Norway