Dexmedetomidine is a selective α2-agonist and has sedative, analgesic, and CNS depressive effect. And several experimental study demonstrated the renal protective effect. Intraoperative dexmedetomidine administration can reduce the amount of anesthetics needed and suppress the sympathetic response resulted by surgical stimulation. And dexmedetomidine was reported to reduce the level of serum cortisol, epinephrine and norepinephrine during the operation. Thus, these effects of dexmedetomidine can be expected to reduce the incidence of acute kidney injury.