“…In such cases, several mechanisms may represent the triggering event: preoperative anxiety, stress of surgery, induction of anesthesia, laryngoscopy, perioperative hemodynamic instability, perioperative administration of vasopressors agents, extubation, and postoperative pain (Liu et al, 2010;Lentschener et al, 2006;Gavish et al, 2006;Takayama et al, 2004;Liu S et al, 2008;Ramakrishna et al, 2005;Takigawa et al, 2003;Mizutani et al, 2002;Itoh H et al, 2007;Littlejohn et al, 2008;Jabaudon et al, 2007).…”