Quadratus Lumborum Block After Cytoreductive Surgery and Hyperthermic Intra-peritoneal Chemotherapy

Quadratus Lumborum Block for Analgesia After Cytoreductive Surgery and Hyperthermic Intra-peritoneal Chemotherapy (CRS and HIPEC): a Double-blind Randomized Controlled Trial

This study aims to assess whether transmusculr quadratus lomborum block (QL block) can reduce postoperative pain after cytoreductive surgery and hyperthermic intra-peritoneal chemotherapy (CRS and HIPEC). Patients will be randomly assigned to either QL block group or control group. Ultrasound-guided bilateral transmuscular quadratus lomborum block will be performed in QL block group using 0.375% ropivacaine. Multimodal analgesic regimen including acetaminophen, nonsteroidal antiinflammatory drugs (NSAIDs), and rescue opioids will be used in every patient. Primary outcome is opioid consumption for 24 hours after surgery. Secondary outcomes included pain scores, time to first rescue analgesics, quality of recovery score, length of hospital stay.

Adult patients scheduled to undergo cytoreductive surgery and hyperthermic intra-peritoneal chemotherapy will be screened for eligibility. After induction of general anesthesia, ultrasound-guided bilateral transmuscular quadratus lomborum block will be done in QL block group. 0.375% ropivacaine will be injected to each side. Patients in control group will receive no block. Multimodal analgesia will be applied to every patient for postoperative pain control. Multimodal analgesic regimen included scheduled administration of acetaminophen, NSAIDs, and rescue opioids. Blinded investigator will assess pain scores at rest and on movement at 6, 12, 24, 48, 72 hours after surgery, analgesic consumptions, nausea, vomiting, and quality of recovery questionnaire.

Patients, medical staff who measure outcome variables, and nurses in the recovery room are double-blinded so that medical staff and patients do not know the patient's assigned group.

Bilateral transmuscular QL block will be performed under ultrasound-guidance. Twenty mililiter of 0.375% ropivacaine will be injected to each side.

Arm I (QL block and multimodal analgesia): Bilateral transmuscular QL block will be done. Postoperative multimodal analgesia including administration of acetaminophen, NSAIDs,nefopam, and rescue opioids Arm II (multimodal analgesia without regional block): No block will be done. Postoperative multimodal analgesia including administration of acetaminophen, NSAIDs, nefopam, and rescue opioids

Patient satisfaction with pain control in 11 point scale (0-10), The higher the score, the higher the patient's satisfaction

Each item uses an 11-point numeric rating scale. The sum of the scores of the 15 items ranges from 0 to 150, with a high score indicating good quality of recovery.

Numeric rating scale at post anesthetic care unit. Numeric rating scare is 11-point scale from 0 to 10. The higher the number, the more severe the pain (0 is no pain at all, 10 is the most severe pain imaginable).

Inclusion Criteria: - Adult patients who are scheduled to undergo cytoreductive surgery and hyperthermic intra-peritoneal chemotherapy (CRS and HIPEC) Exclusion Criteria: Allergy to local anesthetics or fentanyl Chronic pain Drug abuse Patients who are unable to use patient-controlled analgesia Skin infection at site for quadratus lomborum block pregnant or breatfeeding women Patients who are unable to communicate