Quadroiliac Plane Block for Analgesia After Renal Transplantation

Renal transplantation is a major abdominal surgical procedure that may cause moderate to severe postoperative pain. Opioids are commonly used as part of multimodal analgesia; however, opioid-related adverse effects such as sedation, respiratory depression, nausea, vomiting, and constipation may delay recovery and mobilization. The quadroiliac plane block is an ultrasound-guided interfascial plane block performed near the attachment of the quadratus lumborum muscle to the iliac crest. The technique may provide analgesia over a broad lower abdominal area and may reduce postoperative opioid requirements. This prospective, randomized, double-blind, controlled clinical trial will compare an ultrasound-guided unilateral quadroiliac plane block with surgical wound infiltration in adult patients undergoing renal transplantation. Participants will be randomly assigned to receive either a quadroiliac plane block with 40 mL of 0.25% bupivacaine or surgical wound infiltration with 10 mL of 0.25% bupivacaine. All participants will receive standardized multimodal analgesia and intravenous patient-controlled analgesia with tramadol. The primary objective is to compare cumulative tramadol consumption during the first 24 hours after surgery. Postoperative pain scores, dermatomal sensory distribution, motor block, nausea, vomiting, sedation, and quality of recovery will also be evaluated.

Inclusion Criteria: * Age between 18 and 80 years * American Society of Anesthesiologists physical status I-III * Scheduled to undergo renal transplantation surgery * Ability to understand the study procedures and postoperative assessments * Provision of written informed consent Exclusion Criteria: * Known allergy to bupivacaine or other amide-type local anesthetics * Infection at the planned injection site * Coagulopathy or anticoagulant therapy associated with an unacceptable bleeding risk for regional anesthesia * Sepsis * Severe spinal deformity or anatomical abnormality preventing performance of the quadroiliac plane block * Inability to cooperate or communicate reliably * Cognitive impairment or intellectual disability preventing informed consent or reliable outcome assessment * Altered level of consciousness * Breastfeeding * Refusal to participate