Patients were randomly assigned to 3 groups ; patients of group dexamethasone ( group D ) were administrated 8 mg dexamethasone before induction of anesthesia , patients of group propofol ( group P ) were infused to subhypnotic ( 1 mg/kg/h ) propofol during operation and patients of group control ( group C ) were applied infusion of 10 % intralipid .