[1] Univ Barcelona, Dept Anesthesiol, Orthoped Anesthesia Sect, Hosp Clin, Barcelona, Spain
[2] Madrid Monteprincipe Univ Hosp, Dept Anesthesiol, Madrid, Spain
[3] CEU San Pablo Univ, Sch Med, Dept Clin Med Sci, Madrid, Spain
[4] CEU San Pablo Univ, Sch Med, Appl Mol Med Inst, Madrid, Spain
[5] Univ Barcelona, Dept Pathol, Hosp Clin, Barcelona, Spain
[6] Univ Barcelona, Fac Med, Lab Surg Neuroanat, Barcelona 7, Spain