[1] Univ Milan, Dept Hlth Sci, I-20122 Milan, Italy
[2] San Paolo Univ Hosp Milan, Dept Anesthesia & Intens Care, ASST Santi Paolo & Carlo, I-20142 Milan, Italy
[3] Univ Milan, Coordinated Res Ctr Resp Failure, I-20122 Milan, Italy
[4] Luigi Sacco Univ Hosp, ASST Fatebenefratelli Sacco, Div Resp Dis, I-20157 Milan, Italy
[5] Univ Milan, Dept Biomed & Clin Sci, I-20157 Milan, Italy