<qa>  What is the dose of dexmedetomidine?The purpose of our study is to compare liver injury with dexmedetomidine. The enrolled patients were randomized into two group. In the study group, dexmedetomidine, diluted in 0.9 sodium chloride with the concentration of 4 ug ml-1 is administered with an loading dose of 0.5ug kg-1 of 10 min, and maintained with infusion rate of 0.5 ug kg-1 h-1. While, 0.9 sodium chloride serves as the placebo with the same loading dose and infusion rate in the control group. The infusion is ceased after the resection of the hepatic issues. 