[1] San Paolo Univ Hosp Milan, Dept Anesthesia & Intens Care, ASST Santi Paolo & Carlo, Via Di Rudini 9, I-20142 Milan, Italy
[2] Polo Univ, Osped Luigi Sacco, Div Resp Dis, ASST Fatebenefratelli Sacco, Milan, Italy
[3] Univ Milan, Dept Biomed & Clin Sci DIB, Milan, Italy
[4] Univ Milan, Dept Hlth Sci, Milan, Italy
[5] Univ Milan, Coordinated Res Ctr Resp Failure, Milan, Italy