Various maneuvers are commonly used to achieve the ideal operative field necessary for successful endoscopic sinus surgery (ESS). Dexmedetomidine, a potent alpha2 adrenoceptor agonist which dose-dependently reduces arterial blood pressure and heart rate, decreases the hemodynamic and catecholamine response. And dexmedetomidine has an effect of peripheral vasoconstriction thus it is thus theologically appropriate for reducing bleeding during intranasal operation.