1. Rigshospitalet; Abdominal Centre, 3133; Blegdamsvej 9 Copenhagen Denmark 2100
2. Lund University; Clinical Health Promotion Centre, Faculty of Medicine; Lund Sweden
3. Danish Nurses Organization; Sankt Annae plads 30 Copenhagen K Denmark 12503
4. University of Copenhagen Herlev Hospital; The Cochrane Anaesthesia Review Group, Rigshospitalet & Department of Anaesthesiology; Herlev Ringvej Herlev Denmark 2730