In the control group , after induction of anesthesia , a continuous infusion of 0.9 % normal saline ( NS ) 200 mL was given in a speed of 2 mL/min , while a continuous infusion of Xuebijing 2 mL/kg in 100 mL of 0.9 % NS was given at 2 mL/min in the treatment group after induction of anesthesia .