An interventional study of Ultrasound-Guided Lateral Quadratus Lumborum Block (QL1) and Ultrasound-Guided Transversus Abdominis Plane Block in Postoperative Pain, Midline Laparotomy and Abdominal Surgery, sponsored by Sheikh Zayed Medical College. Not yet recruiting at 1 site in Pakistan. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-09-01.
Sponsored by Sheikh Zayed Medical College · Not applicable, Interventional, and Treatment
This randomized controlled trial compares the analgesic efficacy of ultrasound-guided bilateral lateral quadratus lumborum block (QLB, QL1) versus ultrasound-guided bilateral transversus abdominis plane (TAP) block in adults undergoing elective midline laparotomy under general anesthesia. The primary focus is postoperative pain intensity, time to first rescue analgesia, proportion requiring rescue analgesia, and total opioid consumption in the first 24 hours.
Midline laparotomy is associated with significant postoperative pain that can limit mobilization, impair respiratory function, and increase opioid-related side effects. Abdominal wall blocks such as the transversus abdominis plane (TAP) block and quadratus lumborum block (QLB) are used as part of multimodal analgesia. TAP primarily targets somatic afferents of the anterior abdominal wall, while QLB may provide broader coverage including potential paravertebral spread via the thoracolumbar fascia, potentially offering longer-lasting analgesia.
This single-center, prospective, randomized controlled trial will enroll 100 adults (50 per group) aged 18-65 years, ASA physical status I-III, scheduled for elective midline laparotomy under general anesthesia. Participants will be randomized 1:1 using sequentially numbered, opaque, sealed envelopes prepared by an independent research assistant. Both blocks will be performed after induction of general anesthesia and before surgical incision by an experienced anesthesiologist under ultrasound guidance and strict aseptic precautions.
Group A (QLB): Bilateral lateral quadratus lumborum (QL1) block with 20 mL of 0.25% bupivacaine per side (total 40 mL / 100 mg, not exceeding 2 mg/kg).
Group B (TAP): Bilateral TAP block with 20 mL of 0.25% bupivacaine per side (total 40 mL / 100 mg, not exceeding 2 mg/kg).
Postoperative analgesia will be standardized with intravenous paracetamol 1 g every 6 hours. Pain will be assessed using the Numerical Rating Scale (NRS 0-10) at 6, 12, and 24 hours by an independent, blinded outcome assessor. Rescue analgesia (intravenous morphine or tramadol) will be given for NRS ≥4. Primary and secondary analgesic outcomes include NRS scores, time to first rescue analgesia, proportion requiring rescue analgesia within 24 hours, and total opioid consumption in the first 24 hours. Block-related complications will also be recorded.
Statistical analysis will use SPSS version 26. Normality will be assessed by Shapiro-Wilk test. Continuous variables will be compared with independent-samples t-test or Mann-Whitney U test; categorical variables with Chi-square or Fisher's exact test. Potential confounders will be addressed by stratification. A two-sided p-value ≤0.05 will be considered statistically significant.
5,640 studies on the registry are indexed under Pain, Postoperative; 1,230 are open to participants now.
This study's planned enrollment of 100 is above the median of 75 across 4,821 interventional studies indexed under Pain, Postoperative.
Browse Pain, Postoperative studies →Sheikh Zayed Medical College is the lead sponsor of 27 studies on the registry; 8 are open to participants now.
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Exclusion Criteria:
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.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
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.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive bilateral ultrasound-guided lateral quadratus lumborum (QL1) block after induction of general anesthesia and before surgical incision. 20 mL of 0.25% bupivacaine is injected on each side (total 40 mL / 100 mg, dose not exceeding 2 mg/kg).
Procedure: Ultrasound-Guided Lateral Quadratus Lumborum Block (QL1) · Drug: Bupivacaine 0.25%
Participants receive bilateral ultrasound-guided transversus abdominis plane block after induction of general anesthesia and before surgical incision. 20 mL of 0.25% bupivacaine is injected on each side (total 40 mL / 100 mg, dose not exceeding 2 mg/kg).
Procedure: Ultrasound-Guided Transversus Abdominis Plane Block · Drug: Bupivacaine 0.25%
After induction of general anesthesia and before surgical incision, under strict aseptic precautions, a low-frequency curvilinear ultrasound transducer is placed between the costal margin and iliac crest. An echogenic 22-gauge 80-100 mm block needle is advanced in-plane toward the anterolateral border of the quadratus lumborum muscle near the junction of the transversus abdominis aponeurosis and transversalis fascia. After hydrodissection and negative aspiration, 20 mL of 0.25% bupivacaine is injected on each side under continuous ultrasound visualization of local anesthetic spread. Total planned volume 40 mL (100 mg bupivacaine), not exceeding 2 mg/kg.
Also known as: QLB, QL1 Block
After induction of general anesthesia and before surgical incision, under strict aseptic precautions, a high-frequency linear ultrasound transducer is placed transversely on the anterolateral abdominal wall between the costal margin and iliac crest. The external oblique, internal oblique, and transversus abdominis muscles are identified. An echogenic 22-gauge block needle is advanced in-plane until the tip lies in the fascial plane between the internal oblique and transversus abdominis muscles. After hydrodissection and negative aspiration, 20 mL of 0.25% bupivacaine is injected on each side under continuous ultrasound visualization of local anesthetic spread. Total planned volume 40 mL (100 mg bupivacaine), not exceeding 2 mg/kg.
Also known as: TAP Block, TAPB
Local anesthetic used for both QLB and TAP blocks: 20 mL of 0.25% bupivacaine per side (total 40 mL / 100 mg), dose adjusted not to exceed 2 mg/kg body weight.
Postoperative pain intensity at 12 hours
Pain intensity measured using the Numerical Rating Scale (NRS; 0 = no pain, 10 = worst imaginable pain) assessed by an independent blinded outcome assessor.
Time frame: 12 hours after completion of surgery
Postoperative pain intensity at 6 hours
Pain intensity measured using the Numerical Rating Scale (NRS 0-10) by an independent blinded outcome assessor.
Time frame: 6 hours after completion of surgery
Postoperative pain intensity at 24 hours
Pain intensity measured using the Numerical Rating Scale (NRS 0-10) by an independent blinded outcome assessor.
Time frame: 24 hours after completion of surgery
Time to first rescue analgesia
Time (in minutes or hours) from completion of surgery to the first administration of rescue analgesia for NRS score ≥4.
Time frame: From completion of surgery up to 24 hours postoperatively
Proportion of participants requiring rescue analgesia within 24 hours
Percentage of participants who receive at least one dose of rescue analgesia (for NRS ≥4) within the first 24 postoperative hours.
Time frame: First 24 hours after surgery
Total opioid/rescue analgesic consumption within 24 hours
Cumulative dose of opioid or rescue analgesic administered within the first 24 postoperative hours, recorded from the medication administration record.
Time frame: First 24 hours after surgery
Incidence of block-related complications
Any complication considered related to QLB or TAP block (e.g., local anesthetic systemic toxicity, hematoma, infection, nerve injury, block failure).
Time frame: During block performance and within 24 hours after the block
Plan to share: No — Individual participant data will not be shared.
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Sheikh Zayed Medical College