Objective To investigate the inhibition degree of dexmedetomidine(DEX)on patients' psychophysical stress before anesthesia for surgery.Methods 100 patients aged from 20 to 60 with ASA of gradeⅠtoⅡ,who had been scheduled for surgery,were randomly divided into the experimental group(Group A)and the control group(Group B).The experimental group were given 1μg/kg of DEX by intranasal instillation 45mins before anesthesia,while the control group were given the same volume of saline(also by intranasal instillatio...