Effect of Quadratus Lumborum Block With Compound Lidocaine and Esketamine on Pain After Colorectal Surgery

Effect of Ultrasound-guided Quadratus Lumborum Block With Compound Lidocaine and Esketamine on Postoperative Pain in Patients Undergoing Colorectal Surgery: a Randomized Double-blind Controlled Trial

Purpose:

To explore effects of ultrasound-guided quadratus lumborum block with compound lidocaine and esketamine on postoperative pain after colorectal surgery.

Poor post-surgical pain control is a leading factor that hinders the physicalrehabilitation, and causes acute cognitive impairment and chronic painsyndrome. Recently, the multimodal analgesia strategies to minimise opioidrelated side effects are highly desirable in open surgical procedures. Quadratus lumborum block is a novel technique. Although ropivacaine is most commonly used forthis technique, the analgesic duration remains not dissatisfied. Compared with ropivacaine, compound lidocaine injection has a better and longer analgesic activity since it contains menthol and ethanol with appropriate concentrations. However, whether compound lidocaine injection is efficiency in the quadratus lumborum block for abdominal surgery lacks investigations. Herein, we will evaluate the efficacy of ultrasound-guided quadratus lumborum block (USG-QLB) with compound lidocaine injection and esketamine for postoperative analgesia in patients undergoing colorectal surgery.

Inclusion Criteria:

1. Subject is scheduled to undergo colorectal cancer surgery under general anesthesia
2. Subject's American Society of Anesthesiologists physical status is I-III.
3. The subject's parent/legally authorized guardian has given written informed consent to participate

Exclusion Criteria:

1. Subject has a diagnosis of bronchial asthma, coronary heart disease, severe hypertension, renal failure or liver failure.
2. Subject has a diagnosis of Insulin dependent diabetes.
3. Subject is allergy and contraindication to local anesthetics or any components of local anesthetics.
4. Subject has a history of chronic pain, a history of alcohol or opioid abuse, pre- existing therapy with opioids, intake of any analgesic drug within 48 hours before surgery.
5. Subject has any contraindication for the use of patient-controlled analgesia (PCA).
6. Subject is pregnant or breast-feeding.
7. Subject is obese (body mass index >30kg/m^2).
8. Subject is incapacity to comprehend pain assessment and cognitive assessment.