Group 1 received 0.2 % plain ropivacaine 0.75 mlkg ( -1 ) , while group 2 , 3 , and 4 received dexmedetomidine 0.5 , 1.0 , and 1.5 gkg ( -1 ) , respectively , along with 0.2 % ropivacaine 0.75 mlkg ( -1 ) .