Quadroiliac Plane Block for Analgesia After Renal Transplantation

This study is designed as a prospective, randomized, double-blind, parallel-group, controlled clinical trial involving adult patients undergoing renal transplantation.

Eligible participants will be randomly assigned in a 1:1 ratio to either the quadroiliac plane block group or the surgical wound infiltration group. A computer-generated block-randomization sequence will be used. Treatment assignments will be concealed in sequentially prepared, sealed envelopes and managed by a study team member who is not involved in postoperative outcome assessment.

Participants and postoperative outcome assessors will be masked to group allocation. The anesthesiologist performing the assigned intervention will be aware of the allocation but will not participate in postoperative data collection. The intervention will be performed while the participant remains anesthetized.

Quadroiliac Plane Block Group Participants assigned to the experimental group will receive an ultrasound-guided unilateral quadroiliac plane block on the surgical side. The participant will be placed in the lateral decubitus position. A low-frequency curvilinear ultrasound transducer will be positioned immediately above the posterior superior iliac spine and oriented parallel to the vertebral column.

The quadratus lumborum muscle, its attachment to the iliac crest, and the erector spinae muscle will be identified. A 22-gauge, 80-mm echogenic block needle will be advanced using an in-plane approach toward the fascial plane between the quadratus lumborum and erector spinae muscles. After confirmation of the target plane by hydrodissection and negative aspiration, 40 mL of 0.25% bupivacaine will be administered.

Surgical Wound Infiltration Group Participants assigned to the active-comparator group will receive surgical wound infiltration after completion of surgical closure. A total of 10 mL of 0.25% bupivacaine will be administered along the surgical incision into the subcutaneous tissues using an evenly distributed infiltration technique.

Standardized Postoperative Analgesia

At the end of surgery, all participants will receive the following intravenous medications:

Tramadol 100 mg Paracetamol 1 g Dexketoprofen 50 mg Postoperatively, intravenous paracetamol 1 g will be administered three times daily.

Intravenous patient-controlled analgesia will be provided using tramadol at a concentration of 3 mg/mL. The device will be programmed to deliver a 20 mg patient-initiated bolus with a 15-minute lockout interval and without a background infusion.

Outcome Assessments Postoperative pain intensity will be evaluated using an 11-point Numerical Rating Scale ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain. Pain scores will be assessed both at rest and during movement at postoperative hours 0, 1, 6, 12, and 24.

The primary outcome will be cumulative tramadol consumption recorded by the patient-controlled analgesia device during the first 24 postoperative hours.

The sensory distribution of the quadroiliac plane block will be assessed at postoperative hour 2 using a cold sensation test with an ice cube. Relevant abdominal dermatomes will be evaluated, and areas with reduced or absent cold sensation will be recorded.

Postoperative motor function will be evaluated at predefined assessment times. The presence of nausea, vomiting, and sedation will also be recorded during the first 24 postoperative hours.

Quality of postoperative recovery will be evaluated using the Quality of Recovery-11 questionnaire at postoperative hour 24.

The study aims to determine whether the ultrasound-guided quadroiliac plane block reduces postoperative tramadol consumption and improves analgesia and recovery compared with surgical wound infiltration in patients undergoing renal transplantation.

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