Analgesic Effect of Quadratus Lumborum Block in Laparoscopic Hemicolectomy

All patients will receive standard anaesthesia using fentanyl, protocol, cisatracurium and sevoflurane. Prevention of nausea and vomiting is performing using Apfel score. All patients will receive post operative multimodal analgesia using paracetamol, ketoprofen, tramadol, and trimeperidine if numerical rating scale > 3 The study assumes use of QL block by levobupivacaine.in comparison with placebo in order to demonstrate the effectiveness of QL block during the operation.

Distribution: randomized Intervention model: parallel distribution 2 groups Control group: patients receiving general anesthesia with propofol, fentanyl and cisatracurium for induction and sevoflurane, fentanyl and cisatracurium for maintaining anesthesia. Patients receiving postoperative multimodal intravenous analgesia with paracetamol, ketoprofen, tramadol, and trimeperidine. Before surgery will be performde bilateral blockade of the QL muscle with normal saline. Study group: patients receiving general anesthesia with propofol, fentanyl and cisatracurium for induction and sevoflurane, fentanyl and cisatracurium for maintaining anesthesia. Patients receiving postoperative multimodal intravenous analgesia with paracetamol, ketoprofen, tramadol, and trimeperidine. The QL blockade will be performed under ultrasound guidance using 20 ml of a solution of levobupivacaine 2.5 mg / ml.

Triple blindness. The Principal Investigator performing the blockade knows the randomization group. The anesthesiologist, postoperative pain assessor, and study participant do not know the randomization group.

patients receiving general anesthesia with propofol, fentanyl and cisatracurium for induction and sevoflurane, fentanyl and cisatracurium for maintaining anesthesia. Patients receiving postoperative multimodal intravenous analgesia with paracetamol, ketoprofen, tramadol, and trimeperidine. In this group, after induction of anesthesia before the operation, bilateral blockade of the square dorsi muscle is performed under ultrasound guidance using 20 ml of a solution of levobupivacaine 2.5 mg / ml.

patients receiving general anesthesia with propofol, fentanyl and cisatracurium for induction and sevoflurane, fentanyl and cisatracurium for maintaining anesthesia. Patients receiving postoperative multimodal intravenous analgesia with paracetamol, ketoprofen, tramadol, and trimeperidine. In this group, after induction of anesthesia before surgery, bilateral blockade of the square dorsi muscle is performed under ultrasound guidance using 20 ml of saline.

QL block will be used for perioperative anesthesia. The blockade will be performed bilaterally by levobupivacaine (20ml) at concentration 0.25%.

after induction into anesthesia, immediately after the end of the surgery, 12 hours after the surgery

after induction into anesthesia, immediately after the end of the surgery, 12 hours after the surgery

Inclusion Criteria: Patients who have undergone left-sided or right-sided laparoscopic hemicolectomy. Patient's willingness and ability to sign an informed consent document Exclusion Criteria: Allergy to local anesthetics Chronic pain syndrome and associated opioid use. Coagulopathy Uncontrolled diabetes mellitus Physical Status Classification System scale above 3 Diseases associated with the pathology of the hypothalamus Diseases associated with the pathology of the pituitary gland Diseases associated with the pathology of the adrenal glands