1. Department of Anesthesiology, University of Rome La Sapienza, Via Acherusio 16, 00199 Rome, Italy
2. Department of Anesthesiology, The Ohio State University Wexner Medical Center, N411 Doan Hall, 410 W. 10th Avenue, Columbus, OH 43210, USA
3. Department of Anesthesiology, University of Rome La Sapienza, Via Siracusa 12, 0016 Rome, Italy