patients who meet the enrollment criteria will be randomized 1:1:1:1 to the different doses of lidocaine or the placebo group. In the lidocaine groups, at the beginning of surgery, lidocaine 0.5mg/kg, 1.0mg/kg, and 1.5mg/kg per hour were continuously infused (using ideal body weight) respectively during the whole procedure. In contrast, the control group was infused with the same dose of normal saline. All the infusion procedures will be stopped at the end of surgery. Subsequently, all subjects will receive an analgesic device named Patient-Controlled Intravenous Analgesia pump, briefly, PCIA pump during the first 72 postoperative hours. PCIA pump contains lidocaine 30mg/kg, sufentanil 2 μg/kg, and granisetron 12 mg diluted to 200 mL in 0.9 % normal saline, while in the placebo group, the lidocaine will be replaced with the equal dose of 0.9% normal saline and other components unchanged. All the background infusions of PCIA will be set at 2 ml/h, the bolus volume of each PCIA press is 2 ml and the lockout interval is 15 min.
patients who meet the enrollment criteria will be randomized 1:1:1:1 to the different doses of lidocaine or the placebo group. In the lidocaine groups, at the beginning of surgery, lidocaine 0.5mg/kg, 1.0mg/kg, and 1.5mg/kg per hour were continuously infused (using ideal body weight) respectively during the whole procedure. In contrast, the control group was infused with the same dose of normal saline. All the infusion procedures will be stopped at the end of surgery