[1] Papageorgiou Hosp, Intens Care Unit, Pavlos Melas, Greece
[2] Aristotle Univ Thessaloniki, G Papanikolaou Hosp, Resp Failure Dept, Thessaloniki, Greece
[3] G Gennimatas Hosp, Intens Care Unit, Athina, Greece
[4] Aristotle Univ Thessaloniki, AHEPA Hosp, Dept Anesthesia & Intens Care, Thessaloniki, Greece
[5] Hippokrateion Hosp, Dept Resp Med, Thessaloniki, Greece
[6] Hippokrateion Hosp, Dept Resp Med, 49 Konstantinoupoleos Str, Thessaloniki 54642, Greece