1. Department of Anesthesiology, “Papageorgiou” General Hospital of Thessaloniki, 56429 Thessaloniki, Greece
2. Department of Anesthesiology, Medical School, Democritus University of Thrace, General Hospital of Alexandroupolis, 68100 Alexandroupoli, Greece
3. 4th Department of Surgery, Medical School, Aristotle University of Thessaloniki, “Georgios Papanikolaou” General Hospital of Thessaloniki, 57010 Thessaloniki, Greece
4. Department of Anesthesiology, “Georgios Papanikolaou” General Hospital of Thessaloniki, 57010 Thessaloniki, Greece