1 Department of Cardiac-Thoracic and Vascular Diseases, Respiratory and Critical Care Unit, University Hospital St. Orsola-Malpighi, Bologna, Italy.
2 Division of Pulmonary, Critical Care, and Sleep Medicine, Tufts Medical Center, Boston, MA.
3 Department of Clinical, Integrated and Experimental Medicine, Alma Mater Studiorum University of Bologna, Bologna, Italy.
4 Medical Department of Continuity of Care and Disability, Physical Medicine and Rehabilitation, University Hospital St. Orsola-Malpighi, Bologna, Italy.
5 Department of Clinical, Integrated and Experimental Medicine, Alma Mater Studiorum University of Bologna, Bologna, Italy. Electronic address: stefano.nava@aosp.bo.it.