An interventional study of Posterior Quadratus Lumborum Block (QL2) and Transmuscular Quadratus Lumborum Block (QL3) in Postoperative Pain, Inguinal Hernias and Undescended Testis, sponsored by Beni-Suef University. Not yet recruiting at 1 site in Egypt. Open to participants aged 1 Year to 7 Years. Per ClinicalTrials.gov, last updated 2026-11-09.
Sponsored by Beni-Suef University · Not applicable, Interventional, and Treatment
The quadratus lumborum block (QLB) is an established regional anesthesia technique that provides somatic and visceral analgesia for abdominal wall procedures in both adult and pediatric populations. Among its standardized approaches, the posterior QLB (QL2-injectate deposited in the lumbar interfascial triangle at the posterior surface of the quadratus lumborum muscle) and the transmuscular QLB (QL3-injectate deposited in the fascial plane between the anterior surface of the quadratus lumborum and psoas major muscles) are widely utilized.
Although cadaveric and radiological studies suggest that transmuscular QLB yields greater anterior and thoracic paravertebral spread compared to the posterior approach, comparative clinical evidence in pediatric populations remains limited.
The objective of this randomized, prospective, double-blind controlled trial is to compare the analgesic efficacy of ultrasound-guided posterior QLB (QL2) versus transmuscular QLB (QL3) using an identical weight-based dose and concentration of local anesthetic (0.4 mL/kg of bupivacaine 0.25%) in children aged 1 to 7 years undergoing elective unilateral lower abdominal surgery (e.g., inguinal herniotomy, orchiopexy, hydrocelectomy). The primary hypothesis is that one approach will provide superior 24-hour cumulative opioid-sparing analgesia compared to the other.
Background and Anatomical Rationale:
Truncal fascial plane blocks like the quadratus lumborum block (QLB) play a key role in pediatric multimodal analgesia. While posterior QLB (QL2) targets the lumbar interfascial triangle (LIFT) with minimal anatomical risk to deep structures, transmuscular QLB (QL3) penetrates the QL muscle to deposit local anesthetic in the anterior fascial plane adjacent to the psoas major muscle. This study evaluates whether these anatomical differences translate into distinct clinical analgesic outcomes in pediatric patients.
Anesthetic Protocol and Block Execution:
Following standardized general anesthesia induction and airway securing, children assigned to either group receive an ultrasound-guided unilateral block in the lateral decubitus position using the classic "Shamrock" sonographic landmark view (L3 transverse process level).
Posterior QLB Group (QL2): A short-bevel echogenic needle is advanced in-plane to the posterior aspect of the quadratus lumborum muscle (QLM) within the lumbar interfascial triangle.
Transmuscular QLB Group (QL3): An identical needle is advanced transmuscularly through the QLM into the fascial plane between the anterior surface of the QL and psoas major muscle.
In both groups, plane identification is confirmed by hydrodissection (1-2 mL saline/D5W), followed by slow injection of 0.4 mL/kg bupivacaine 0.25% (1 mg/kg; maximum 20 mL) with intermittent aspiration every 3-5 mL.
Postoperative Analgesic Management and Assessment:
Postoperative behavioral pain intensity is monitored by a blinded observer using the Face, Legs, Activity, Cry, Consolability (FLACC) score at 0 (PACU arrival), 1, 2, 4, 6, 12, 18, and 24 hours postoperatively. Stepwise rescue analgesia is initiated for FLACC scores ≥4: intravenous paracetamol 15 mg/kg (if >6 hours from prior dose), followed by rescue intravenous fentanyl 0.5 µg/kg or morphine 0.05 mg/kg if pain persists.
Sedation (University of Michigan Sedation Scale), motor block (modified Bromage scale), time to first rescue request, incidence of postoperative nausea and vomiting (PONV), parental satisfaction (5-point Likert scale), and time to post-anesthesia discharge readiness are systematically evaluated.
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Children aged 1 to 7 years. (ASA) physical status I or II. Scheduled for elective unilateral lower abdominal surgery under general anesthesia with a planned quadratus lumborum block for postoperative analgesia (e.g., inguinal herniotomy, orchiopexy, hydrocelectomy).
Written obtained from a parent or legal guardian.
Exclusion Criteria:
Parental or guardian refusal to participate. Known allergy or to amide local anesthetics. Coagulopathy or active use of anticoagulant or antiplatelet medication. Local skin infection at the intended regional block injection site. Planned bilateral surgical procedure. Significant hepatic, renal, cardiac, or neuromuscular disease. Developmental delay or medical condition precluding reliable pain-scale assessment.
Preoperative chronic opioid or regular analgesic use. Body weight below the 3rd percentile for age, or known spinal/vertebral column anomaly precluding safe block performance.
Emergency surgery.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Children assigned to this arm receive a single-dose, ultrasound-guided posterior quadratus lumborum block (QL2) performed after induction of general anesthesia and prior to surgical incision. Under ultrasound guidance, a short-bevel echogenic needle is advanced to the posterior surface of the quadratus lumborum muscle within the lumbar interfascial triangle (LIFT). Local anesthetic is deposited following hydrodissection confirmation and negative aspiration.
Procedure: Posterior Quadratus Lumborum Block (QL2)
Children assigned to this arm receive a single-dose, ultrasound-guided transmuscular quadratus lumborum block (QL3) performed after induction of general anesthesia and prior to surgical incision. Under ultrasound guidance using the "Shamrock" view, a short-bevel needle is advanced transmuscularly through the quadratus lumborum muscle to deposit local anesthetic in the fascial plane between its anterior surface and the psoas major muscle following hydrodissection confirmation and negative aspiration.
Procedure: Transmuscular Quadratus Lumborum Block (QL3)
Ultrasound-guided single-injection posterior quadratus lumborum block performed pre-incisions under general anesthesia. Local anesthetic: 0.4 mL/kg of bupivacaine 0.25% (1 mg/kg; maximum single-side volume 20 mL) deposited at the posterior border of the QL muscle within the lumbar interfascial triangle.
Also known as: QL2 block, Lumbar interfascial triangle block
Ultrasound-guided single-injection transmuscular quadratus lumborum block performed pre-incisions under general anesthesia. Local anesthetic: 0.4 mL/kg of bupivacaine 0.25% (1 mg/kg; maximum single-side volume 20 mL) deposited in the plane between the anterior surface of the QL muscle and psoas major muscle.
Also known as: Anterior/Lateral QLB, Shamrock approach QLB
Total Cumulative Opioid Consumption in the First 24 Hours
Total cumulative dose of intraoperative and postoperative rescue opioids administered during the first 24 hours postoperatively, converted to intravenous morphine-equivalent doses (mg/kg) using standard conversion ratios and normalized to body weight. A lower numerical value indicates a superior clinical outcome (greater opioid-sparing effect and reduced opioid requirement).
Time frame: First 24 hours postoperatively
Postoperative Pain Intensity Scores
Postoperative pain intensity measured using the Face, Legs, Activity, Cry, Consolability (FLACC) behavioral pain scale. Scores range from 0 to 10, where 0 represents no pain (relaxed and comfortable; best outcome) and 10 represents severe pain/discomfort (worst outcome). Lower numerical scores represent better pain control.
Time frame: At 0 (PACU arrival), 1, 2, 4, 6, 12, 18, and 24 hours postoperatively
Time to First Rescue Analgesia Request
Time elapsed (in minutes) from arrival in the Post-Anesthesia Care Unit (PACU) until the first administration of rescue analgesic (triggered by a FLACC score ≥4). A higher numerical value (longer duration of time) indicates a superior clinical outcome (prolonged block duration and delayed pain onset).
Time frame: Up to 24 hours postoperatively
Block Execution Time
Total time required to perform the ultrasound-guided regional block, measured in seconds from initial placement of the ultrasound transducer on the skin to needle withdrawal. Lower execution times represent greater technical ease and efficiency (better procedural performance).
Time frame: Intraoperatively (during block performance)
Number of Needle Passes and Redirections
Number of discrete needle skin punctures and forward redirections required to achieve correct needle tip positioning within the intended target fascial plane. A lower count indicates easier needle placement and less tissue trauma (better procedural outcome).
Time frame: Intraoperatively (during block performance)
Incidence and Severity of Postoperative Nausea and Vomiting
Presence and severity of postoperative nausea and vomiting assessed using a 4-point scale (0 = no nausea or vomiting \[best outcome\], 1 = mild nausea, 2 = moderate nausea or single emetic episode, 3 = severe nausea or multiple emetic episodes requiring antiemetic rescue \[worst outcome\]). Lower scores represent a better clinical outcome.
Time frame: At 0, 1, 2, 4, 6, 12, 18, and 24 hours postoperatively
Postoperative Sedation Score
Sedation level evaluated using the University of Michigan Sedation Scale (UMSS), ranging from 0 (awake and alert; normal state) to 4 (unarousable to noxious stimuli; severe sedation/respiratory risk). Lower scores (specifically 0 to 1) represent desirable postoperative alertness and faster recovery.
Time frame: At 0, 1, 2, 4, 6, 12, 18, and 24 hours postoperatively
Incidence and Degree of Lower Limb Motor Blockade
Motor weakness evaluated using a modified Bromage scale (0 = full flexion of knees and feet / no motor block \[best safety outcome\], 1 = partial flexion, 2 = movement of feet only, 3 = complete paralysis of lower limb \[worst outcome\]). A score of 0 indicates an optimal motor-sparing sensory block without unwanted lumbar plexus involvement.
Time frame: At 1, 4, and 8 hours postoperatively
Parental Satisfaction Score
Parental or legal guardian overall satisfaction with post-surgical pain management evaluated on a 5-point Likert scale (1 = very dissatisfied \[worst outcome\], 2 = dissatisfied, 3 = neutral, 4 = satisfied, 5 = very satisfied \[best outcome\]). Higher numerical scores represent a superior clinical outcome.
Time frame: 24 hours postoperatively
Time to Post-Anesthesia Discharge Readiness
Time elapsed (in minutes) from PACU arrival until the child satisfies all criteria of the modified pediatric Post-Anesthesia Discharge Scoring System (PADSS). A lower numerical value (shorter duration of time in minutes) indicates a better outcome (faster recovery and earlier discharge readiness).
Time frame: Up to 24 hours postoperatively
Incidence of Block-Related Adverse Events and Complications
Total count and percentage of procedural complications (including vascular puncture, LAST, peritoneal injury, localized hematoma, or infection). A lower number (ideally 0) indicates a superior safety profile.
Time frame: Through 24 hours postoperatively
Plan to share: Yes — De-identified individual participant data (including primary outcome measures, demographic variables, FLACC pain scores, cumulative opioid consumption, and block execution metrics) will be made available to qualified academic researchers upon reasonable request submitted to the principal investigator, following publication of the primary trial results.
Supporting information: Study protocol, Statistical analysis plan
Time frame: Data will become available 3 months following peer-reviewed journal publication of the primary manuscript and will remain accessible for 3 years.
Access criteria: Data will be shared with recognized medical and academic researchers who submit a sound scientific proposal and a signed data-use agreement to the principal investigator (at Kmnmk87@med.bsu.edu.eg).
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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