1. Departments of Anaesthesiology, Infection Control and Surgery and Division of Intensive Care, University of Oulu and Department of Anaesthesiology, Raahe Community Hospital, Finland
2. Department of Anaesthesiology, Division of Intensive Care, University of Oulu.
3. Department of Anaesthesiology, Raahe Community Hospital.
4. Department of Anaesthesiology and Division of Intensive Care, University of Oulu.
5. Department of Surgery, University of Oulu.
6. Department of Infection Control, University of Oulu.