1. Copenhagen University Hospital, Rigshospitalet; Department of Thoracic Anaesthesiology; Blegdamsvej 9 Copenhagen Denmark 2100
2. West China Hospital, Sichuan University; Chinese Evidence-Based Medicine Centre; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
3. Department 7812, Rigshospitalet, Copenhagen University Hospital; Copenhagen Trial Unit, Centre for Clinical Intervention Research; Blegdamsvej 9 Copenhagen Denmark DK-2100