[1] Sapienza Univ Rome, Fac Med & Psychol, St Andrea Hosp, Div Thorac Surg, Rome, Italy
[2] Univ Aquila, Fac Med & Surg, G Mazzini Hosp Teramo, Div Thorac Surg, Teramo, Italy
[3] Washington Univ, Dept Anesthesiol, St Louis, MO USA
[4] Sapienza Univ Rome, Fac Med & Psychol, St Andrea Hosp, Div Anesthesiol, Rome, Italy
[5] Sapienza Univ Rome, Fac Med & Psychol, St Andrea Hosp, Div Gen Surg, Rome, Italy
[6] Sapienza Univ Rome, Fac Med & Psychol, Dept Stat, Rome, Italy