Retrolaminar Plane Block Versus Anterior Quadratus Lumborum Block in Pediatric Urogenital Surgery

Comparison of the Postoperative Analgesic Efficacy of Retrolaminar Plane Block and Anterior Quadratus Lumborum Block in Pediatric Lower Urogenital Surgery: A Randomized Controlled Trial

Effective control of postoperative pain following pediatric lower urogenital surgery is important for enhancing recovery and reducing opioid requirements. Anterior quadratus lumborum block and retrolaminar block are two ultrasound-guided truncal block techniques used for perioperative analgesia in lower abdominal surgery. However, direct comparisons of their analgesic efficacy in pediatric lower urogenital procedures remain limited.

This prospective, randomized, controlled trial will enroll 76 pediatric patients aged 6 months to 12 years with American Society of Anesthesiologists physical status I-III who are scheduled for elective lower urogenital surgery. Participants will be randomly assigned in a 1:1 ratio to receive either an anterior quadratus lumborum block or a retrolaminar block. Both techniques will be performed under ultrasound guidance in addition to standardized general anesthesia.

The primary outcome will be rescue analgesic requirement during the first 24 postoperative hours. Secondary outcomes will include postoperative pain scores, time to first rescue analgesic administration, intraoperative remifentanil consumption, adverse effects such as nausea and vomiting, and caregiver satisfaction. The study aims to compare the postoperative analgesic efficacy and safety of anterior quadratus lumborum block and retrolaminar block in pediatric patients undergoing lower urogenital surgery.

Study Overview

• Status: Not yet recruiting
• Conditions: Pediatric Postoperative Pain; Retrolaminar Block; Pediatric Regional Anesthesia
• Intervention / Treatment: Procedure: Anterior Quadratus Lumborum Block; Procedure: Retrolaminar Block

Detailed Description

Effective postoperative pain control following pediatric lower urogenital surgery is essential for improving recovery, reducing distress, facilitating oral intake, and decreasing opioid consumption. Ultrasound-guided regional anesthesia techniques have become an important component of multimodal analgesia strategies in pediatric anesthesia. Anterior quadratus lumborum block and retrolaminar block are two truncal block techniques used to provide analgesia for lower abdominal surgical procedures. However, direct comparisons of the postoperative analgesic efficacy of these techniques in pediatric lower urogenital surgery remain limited.

The aim of this study is to compare the postoperative analgesic efficacy of anterior quadratus lumborum block and retrolaminar block in pediatric patients undergoing lower urogenital surgery. Secondary objectives include evaluation of rescue analgesic requirements, postoperative pain scores, time to first rescue analgesic administration, intraoperative opioid consumption, adverse effects, and caregiver satisfaction.

This study is designed as a prospective, randomized, controlled, assessor-blinded clinical trial involving pediatric patients aged 6 months to 12 years with American Society of Anesthesiologists physical status I to III who are scheduled for elective lower urogenital surgery. Eligible participants will be randomly assigned in a 1:1 ratio to either the anterior quadratus lumborum block group or the retrolaminar block group using a computer-generated randomization sequence. Allocation concealment will be maintained using sequentially numbered opaque sealed envelopes.

All patients will receive standardized general anesthesia. Following induction of anesthesia, regional blocks will be performed under sterile conditions with ultrasound guidance. In both groups, 0.25 percent bupivacaine will be administered at a volume of 0.4 milliliters per kilogram.

Intraoperative monitoring will include heart rate and arterial blood pressure measurements recorded at baseline and predefined time points during surgery. If either parameter increases by 20 percent or more compared with baseline values, remifentanil infusion will be initiated and total remifentanil consumption will be recorded.

Postoperative pain assessment will be performed using the Face, Legs, Activity, Cry, and Consolability Scale. This scale ranges from 0 to 10 points, with higher scores indicating greater pain intensity. Rescue analgesia will be administered when the score is 4 or higher.

Patients will be evaluated in the post-anesthesia care unit and during ward follow-up at predefined time points. Pain scores, total rescue analgesic consumption, time to first rescue analgesic administration, adverse events including postoperative nausea and vomiting, and caregiver satisfaction will be recorded.

The primary outcome measure is total rescue analgesic requirement during the first 24 postoperative hours. Secondary outcome measures include postoperative pain scores, time to first rescue analgesic administration, intraoperative remifentanil consumption, incidence of postoperative nausea and vomiting, block success, and caregiver satisfaction.

Based on the sample size calculation, a total of 76 patients will be enrolled. Statistical analyses will be performed using appropriate parametric or nonparametric methods, and a p value less than 0.05 will be considered statistically significant.

• Study Type: Interventional
• Enrollment (Estimated): 76
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: münevver kayhan, Lecturer Doctor; Phone Number: 02124143000; Email: munevver.kayhan@iuc.edu.tr
• Study Contact Backup: Name: Ayse Cigdem Tutuncu, Professor Doctor; Phone Number: 02124143000; Email: actutuncu@gmail.com

Study Locations

• Turkey (Türkiye)
  • Istanbul
    • Bakırköy, Istanbul, Turkey (Türkiye), 34153
      • Istanbul University-Cerrahpasa, Cerrahpasa Medicine of Faculty
      • Contact: münevver kayhan, Lecturer Doctor; Phone Number: 02124143000; Email: munevver.kayhan@iuc.edu.tr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age between 6 months and 12 years
• Scheduled for lower abdominal urogenital surgery (e.g., inguinal hernia repair or orchiopexy for undescended testis)
• American Society of Anesthesiologists physical status classification I-III
• Written informed consent obtained from a parent or legal guardian

Exclusion Criteria:

• History of allergy to local anesthetic agents
• Presence of infection at the planned injection site
• Coagulopathy or any other condition contraindicating regional anesthesia
• Planned laparoscopic orchiopexy
• American Society of Anesthesiologists physical status classification IV
• Inability to obtain informed consent from a parent or legal guardian
• Anticipated requirement for postoperative intensive care unit admission

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Anterior Quadratus Lumborum Block Group; Participants assigned to this group will receive an ultrasound-guided anterior quadratus lumborum block following induction of general anesthesia for postoperative analgesia. The block will be performed under sterile conditions using 0.25 percent bupivacaine at a volume of 0.4 milliliters per kilogram. Standardized general anesthesia and postoperative analgesic protocols will be applied to all participants.	Procedure: Anterior Quadratus Lumborum Block; An ultrasound-guided anterior quadratus lumborum block will be performed after induction of general anesthesia. Following identification of the quadratus lumborum and psoas major muscles, 0.25 percent bupivacaine will be injected into the fascial plane between these muscles at a volume of 0.4 milliliters per kilogram.
Experimental: Retrolaminar Block Group; Participants assigned to this group will receive an ultrasound-guided retrolaminar block following induction of general anesthesia for postoperative analgesia. The block will be performed under sterile conditions using 0.25 percent bupivacaine at a volume of 0.4 milliliters per kilogram. Standardized general anesthesia and postoperative analgesic protocols will be applied to all participants.	Procedure: Retrolaminar Block; An ultrasound-guided retrolaminar block will be performed after induction of general anesthesia. After identification of the target vertebral lamina, 0.25 percent bupivacaine will be administered into the retrolaminar plane at a volume of 0.4 milliliters per kilogram.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Rescue Analgesic Requirement During the First 24 Postoperative Hours	Total rescue analgesic consumption during the first 24 postoperative hours will be recorded. Pain assessment will be performed using the Face, Legs, Activity, Cry, and Consolability Scale. The scale ranges from 0 to 10, with higher scores indicating greater pain intensity. Rescue analgesia will be administered when the score is 4 or higher.	First 24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Pain Scores	Pain intensity will be assessed using the Face, Legs, Activity, Cry, and Consolability Scale. Scores range from 0 to 10, with higher scores indicating greater pain intensity.	Postoperative 1, 2, 4, 8, 16, and 24 hours
Time to First Rescue Analgesic Administration	The time from completion of surgery to the administration of the first rescue analgesic will be recorded in minutes.	First 24 hours after surgery
Intraoperative Remifentanil Consumption	Total remifentanil consumption during surgery will be recorded in micrograms per kilogram.	From induction of anesthesia until the end of surgery

Collaborators and Investigators

• Sponsor: Istanbul University - Cerrahpasa
• Investigators: Principal Investigator: münevver kayhan, Istanbul University-Cerrahpasa, Cerrahpasa Medicine of Faculty; Study Director: Ayse Cigdem Tutuncu, Professor Doctor, Istanbul University-Cerrahpasa, Cerrahpasa Medicine of Faculty; Study Chair: Pinar Kendigelen, Professor Doctor, Istanbul University-Cerrahpasa, Cerrahpasa Medicine of Faculty

Study record dates

Study Major Dates

• Study Start (Estimated): July 25, 2026
• Primary Completion (Estimated): July 20, 2027
• Study Completion (Estimated): September 1, 2027

Study Registration Dates

• First Submitted: July 14, 2026
• First Submitted That Met QC Criteria: July 14, 2026
• First Posted (Actual): July 17, 2026

Study Record Updates

• Last Update Posted (Actual): July 17, 2026
• Last Update Submitted That Met QC Criteria: July 14, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: pediatric anesthesia; pediatric pain management; retrolaminar block; pediatric regional anesthesia
• Other Study ID Numbers: ctf- rlb&antqlb

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No