Effect of Lidocaine on Postoperative Pain in Elderlypatients Undergoing Colorectal Cancer Surgery

Effect of Perioperative Continuous Intravenous Infusion of Lidocaine on Postoperative Pain in Elderly Patients Undergoing Colorectal Cancer Surgery: a Prospective, Randomized Controlled Trial

Patients who meet the enrollment criteria will be randomized 1:1 to the lidocaine group or placebo group.

Patients who meet the enrollment criteria will be randomized 1:1 to the lidocaine group or placebo group. In the lidocaine groups, lidocaine 1.5mg/kg/h was continuously infused (using ideal body weight) during the whole procedure, postoperative analgesia pump with lidocaine (lidocaine 50mg/kg, sufentanil 2ug/kg, glassetron 12mg), diluted to 200ml with saline until 72h after surgery. Blood samples will be collected from some patients in the lidocaine group for the measurement of lidocaine plasma concentration.In the placebo group, the same volume of normal saline will be administered during anesthesia. The postoperative PCIA device will contain sufentanil 2 μg/kg, granisetron 12 mg diluted to 200 mL in 0.9% normal saline solution with a total volume of 200 mL.

Inclusion Criteria:

1. Participants were at least 60 years old;
2. American Society of Anesthesiologists (ASA) physical status I to III;
3. Body-mass index of 18-30 kg/m2;
4. Scheduled for elective colorectal surgery.

Exclusion Criteria:

1. Metastases occurring in other distant organs;
2. Severe hepatic insufficiency (aspartate aminotransferase or alanine transaminase or bilirubin >2.5 times the upper limit of normal);
3. Renal impairment (creatinine clearance <60 mL/min);
4. Cardiac rhythm disorders or systolic heart failure (second-and third-degree heart block, ejection fraction <50%);
5. Allergies to any of the trial drugs; chronic opioid use;
6. Inability to comprehend numeric rating scale.