1. Department 7812, Rigshospitalet, Copenhagen University Hospital; Copenhagen Trial Unit, Centre for Clinical Intervention Research; Blegdamsvej 9 Copenhagen Denmark DK-2100
2. Bispebjerg Hospital, University of Copenhagen; Department of Anaesthesiology; Copenhagen NV Denmark
3. Bispebjerg Hospital, University of Copenhagen; Department of Surgery K; Bispebjerg Bakke 23 Copenhagen Denmark 2400 NV
4. Copenhagen Trial Unit, Centre for Clinical Intervention Research, Department 7812, Rigshospitalet, Copenhagen University Hospital; The Cochrane Hepato-Biliary Group; Blegdamsvej 9 Copenhagen Denmark DK-2100
5. Rigshospitalet, University of Copenhagen; Department of Anaesthesia, Centre of Head and Orthopaedics; Dpt. 4231 Blegdamsvej 9 Copenhagen Denmark DK-2100 Ø