1. Intensive Care Unit, Sismanogleio General Hospital, 15126 Marousi, Greece
2. 1st Anesthesiology Department, Aretaieio Hospital, National and Kapodistrian University of Athens Medical School, 11528 Athens, Greece
3. School of Science and Technology, Hellenic Open University, 26335 Patras, Greece
4. Department of Quality Control, Research and Continuing Education, Sismanogleio General Hospital, 15126 Marousi, Greece
5. Faculty of Nursing, School of Health Sciences, National and Kapodistrian University of Athens, 11527 Athens, Greece