[1] Univ Florence AOU, Dept Clin & Expt Med, Careggi, Italy
[2] Autonomous Univ Madrid, Dept Anat Histol & Neurosci, Appl Anat Lab, Madrid, Spain
[3] Hosp Infanta Leonor, Dept Anesthesia, Madrid, Spain
[4] Cleveland Clin, Anesthesiol Inst, Outcomes Res Dept, Cleveland, OH 44106 USA
[5] Istanbul Univ Cerrahpasa, Cerrahpasa Med Fac, Dept Anesthesiol & Reanimat, Istanbul, Turkey
[6] Mostoles Univ Hosp, Dept Anesthesiol & Reanimat, Madrid, Spain
[7] Hosp Mexico, San Jose, Costa Rica
[8] Hosp Interzonal Gen Dr Jose Penna, Bahia Blanca, Buenos Aires, Argentina