1 Pulmonology Department, University Hospital of Cattinara, and the Department of Medical Surgical and Health Sciences, University of Trieste, Trieste, Italy. Electronic address: mconfalonieri@units.it.
2 Pulmonology Department, University Hospital of Cattinara, and the Department of Medical Surgical and Health Sciences, University of Trieste, Trieste, Italy.
3 Department of Medicine, Division of Critical Care, McMaster University, Hamilton, ON, Canada.
4 Departments of Medicine, Pulmonary, Critical Care, and Sleep Medicine Service, Memphis Veterans Affairs Medical Center, Memphis, TN.