Department of Anaesthesia, Holbæk Hospital, Part of Copenhagen University Hospitals, Holbaek, Denmark. Electronic address: aaaa@regionsjaelland.dk. Department of Surgery, Holbæk Hospital, Part of Copenhagen University Hospitals, Holbaek, Denmark. Department of Surgery, Herlev University Hospital, Herlev, Denmark. Department of Anaesthesia, Herlev University Hospital, Herlev, Denmark. Department of Surgery, Odense University Hospital, Odense, Denmark. Department of Anaesthesia, Odense University Hospital, Odense, Denmark. Department of Surgery, Slagelse Hospital, Part of Copenhagen University Hospitals, Slagelse, Zealand, Denmark. Department of Anaesthesia, Slagelse Hospital, Part of Copenhagen University Hospitals, Slagelse, Zealand, Denmark.