The lidocaine group ( n = @ , Group LIDO ) received an infusion of lidocaine @ mg/kg/h after bolus @ mg/kg ; the dexmedetomidine group ( n = @ , Group DEX ) received dexmedetomidine @-@ @ g/kg/h ; the combined group ( n = @ , Group Combined ) received infusion of both drugs ; and the control group ( n = @ ) received nothing .