1. Division of Intensive Care, Department of Anesthesiology; Oulu University Hospital; Oulu Finland
2. Unit of Nursing Science and Health Management, University; Oulu Finland
3. Medical Research Center; Oulu Finland
4. Chief of Department of Infection Control, Medical Research Center; Oulu University Hospital; Oulu Finland
5. Department of Anesthesiology; Oulu University Hospital; Oulu Finland
6. Division of Intensive Care, Department of Anesthesiology, Oulu University Hospital; Medical Research Center; Oulu Finland
7. Unit of Nursing Science and Health Management; Medical Research Center Northern Ostrobothnia Hospital; Oulu Finland
8. Division of Intensive Care, Department of Anesthesiology; Oulu University Hospital, Oulu, Finland; Medical Research Center; Oulu Finland