1. Faculty of Nursing, National and Kapodistrian University of Athens, Athens, Greece.
2. Department of Anesthesiology, National and Kapodistrian University of Athens, Athens, Greece.
3. Department of Anaesthesia, Tzanio Hospital, Athens, Greece.
4. Department of Microbiology, Evgenidion Hospital Athens, Athens, Greece.
5. Department of Surgery, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
6. Department of Critical Care and Pulmonary Diseases, National and Kapodistrian University of Athens, Athens, Greece.