1. Department of Cardiothoracic Surgery; Landspitali University Hospital; Reykjavik Iceland
2. Department of Anesthesiology, Perioperative and Pain Medicine; Brigham and Women's Hospital; Boston MA USA
3. Faculty of Medicine; University of Iceland; Reykjavik Iceland
4. Department of Nephrology; Landspitali University Hospital; Reykjavik Iceland
5. Department of Anesthesia and Intensive Care Medicine; Landspitali University Hospital; Reykjavik Iceland