Dexmedetomidine group (D)
DrugPatients received 1ug/kg dexmedetomidine in 50 ml saline over 10 min i.v 30 min before induction then 0.4 ug/kg/h dexmedetomidine (4ug/ml) and normal saline 0.1 ml/kg till end of surgery, using two syringe pumps one for dexmedetomidine and the other for saline