In the patients undergoing UPPP under sevoflurane inhalation anesthesia , Dexmedetomidine infused at 0.2 microg x kg ( -1 ) x h ( -1 ) maintains a stable hemodynamics without respiratory depression , alleviates stress response during extubation and reduces both the consumption of sevoflurane and the occurrence of dysphoria without prolonging emergence time and extubation time .