Comparison of ESP and QL Blocks for Postoperative Pain in Pediatric Appendectomy (ESP-QLB)

Appendectomy is one of the most common emergency surgical procedures in children, and effective postoperative analgesia plays a key role in patient comfort, early mobilization, and reduced opioid exposure. Regional anesthesia techniques have gained increasing importance in pediatric anesthesia due to their opioid-sparing effect and favorable safety profile. Among these techniques, the Erector Spinae Plane (ESP) block and the Quadratus Lumborum (QL) block have shown promising results; however, there is a lack of high-quality randomized controlled trials directly comparing their clinical efficacy in pediatric appendectomy.

This study will prospectively enroll pediatric patients between 3 and 13 years of age who are scheduled to undergo appendectomy. After obtaining informed parental consent, participants will be randomly allocated to either the ESP block group or the QL block group. All blocks will be performed under ultrasound guidance using 0.25% bupivacaine at a dose of 0.5 mL/kg following the induction of general anesthesia. Standardized postoperative analgesia protocols will be applied to all participants.

Pain scores will be measured at predefined time points using a validated pediatric pain scale. Secondary outcomes will include total opioid consumption during the first 24 hours, the time to first rescue analgesic requirement, mobilization time, length of hospital stay, parental satisfaction scores, and any block-related complications. Patient data will be collected by trained investigators who will be blinded to group allocation.

The goal of this trial is to determine whether ESP or QL block provides superior postoperative pain control and recovery in pediatric appendectomy. The results may contribute to evidence-based recommendations for regional anesthesia selection in pediatric surgical practice.

• Quadratus Lumborum Block (QLB) (Drug): Ultrasound-guided transmuscular QL block performed under general anesthesia using 0.25% bupivacaine (0.5 mL/kg) before surgical incision.
• Erector Spinae Plane Block (Drug): Ultrasound-guided ESP block at the L1 level under general anesthesia using 0.25% bupivacaine (0.5 mL/kg) before surgical incision.

Primary outcomes

• Postoperative Pain Score [Pain scores will be assessed at 1, 6, 12, and 24 postoperative hours.]: Pain intensity will be evaluated at rest using the Oucher Pain Rating Scale. Higher scores indicate greater pain.

Secondary outcomes

• Total Analgesic Consumption [Recorded during the first 24 hours after surgery]: Total dose of analgesic medications (NSAIDs and/or non-opioid analgesics) administered within the first 24 hours after surgery will be recorded. Higher values indicate greater analgesic requirement.
• Time to First Analgesic Requirement [From the end of surgery until the first documented analgesic requirement, assessed up to 24 hours postoperatively]: Time interval between the end of surgery and the first administration of rescue analgesia will be recorded in minutes. Longer intervals indicate better analgesic effectiveness.
• Time to Mobilization [From the end of surgery until the first successful ambulation with or without assistance, assessed up to 24 hours postoperatively]: Time from the end of surgery until the patient is able to ambulate with assistance or independently will be recorded in minutes. Shorter time indicates faster functional recovery.
• Length of Hospital Stay [From the end of surgery until hospital discharge, typically within 24-48 hours.]: Duration of hospitalization will be recorded from admission to discharge and expressed in hours. Longer duration indicates delayed recovery.
• Parents' Postoperative Pain Measure (PPPM) [Assessed at 1, 6, 12, and 24 hours postoperatively]: Postoperative pain will be evaluated by parents using the Parents' Postoperative Pain Measure (PPPM). Higher scores indicate greater pain intensity.
• Block-Related Complications [From block performance until the end of surgery and during the first 24 hours postoperatively]: ny adverse events potentially related to the regional block (e.g., local hematoma or bruising, infection at the injection site, neurological symptoms, or suspected local anesthetic systemic toxicity) will be recorded as present or absent.
• Block performance time [During block performance, prior to surgical incision]: Block performance time was defined as the time (in seconds) from the initial placement of the ultrasound probe on the skin to the completion of local anesthetic injection. The duration was recorded by an independent observer using a stopwatch.

Sex: All, ages: 3 Years to 13 Years

Inclusion Criteria:

* Patients aged 3-13 years
* Diagnosis of acute appendicitis requiring appendectomy
* ASA physical status I-II
* Planned general anesthesia with intraoperative regional block (ESP or QL block)
* Written informed consent obtained from parents or legal guardians

Exclusion Criteria:

* Refusal of regional block by family or anesthesia team
* Coagulopathy or anticoagulant medication use
* Local infection at the block injection site
* Known allergy or contraindication to local anesthetics
* Neurological or neuromuscular disorders
* Cognitive impairment preventing postoperative pain assessment
* Conversion to open surgery
* Intraoperative complications requiring deviation from study protocol

• Süleyman Camgöz, Principal investigator, Kutahya Health Sciences University