After IV administration of atropine ( 0.01 mg/kg ) , anesthesia was induced with an infusion of dexmedetomidine ( 1 g/kg ) over 2 minutes for group D , whereas normal saline was infused for group P. Propofol ( 3 mg/kg ) was then injected IV over 20 to 30 seconds , followed by an infusion of remifentanil ( 2 g/kg ) over 1 minute for both groups .