1. Pulmonary Department, Aristotle University of Thessaloniki, G. H. “G. Papanikolaou” (Exohi), Thessaloniki, Greece
2. Respiratory Intensive Care Unit, Aristotle University of Thessaloniki, G. H. “G. Papanikolaou” (Exohi), Thessaloniki, Greece
3. 1st Intensive Care Unit, G. H. “G. Papanikolaou” (Exohi), Thessaloniki, Greece