1. Department of Anesthesia, Intensive Care and Emergency, Città della Salute e della Scienza di Torino Hospital, 10126 Torino, Italy
2. Department of Surgical Science, University of Turin, 10124 Torino, Italy
3. Department of Medical Sciences, Infectious Diseases, University of Turin, 10124 Turin, Italy
4. School of Medicine, Tufts University, Boston, MA 02111, USA