1. Department of Endocrinology, Landspitali University Hospital, Reykjavik, Iceland
2. Department of Intensive Care, Landspitali University Hospital, Reykjavik, Iceland
3. Department of Neurosurgery, Landspitali University Hospital, Reykjavik, Iceland
4. University of Iceland, Reykjavik, Iceland
5. Department of Clinical Chemistry, Landspitali University Hospital, Reykjavik, Iceland