The lidocaine group ( n = 36 , Group LIDO ) received an infusion of lidocaine 2 mg/kg/h after bolus 1.5 mg/kg ; the dexmedetomidine group ( n = 40 , Group DEX ) received dexmedetomidine 0.3-0 .7 g/kg/h ; the combined group ( n = 39 , Group Combined ) received infusion of both drugs ; and the control group ( n = 38 ) received nothing .