QL Block Versus EO Plane Block for Analgesia After Open Nephrectomy

August 24, 2026 updated by: Sayed Mahmoud Abed, Cairo University

Quadratus Lumborum Block Versus External Oblique Plane Block for Analgesia After Open Nephrectomy: A Prospective Randomized Clinical Trial

This prospective randomized clinical trial aims to compare two ultrasound-guided regional anesthesia techniques, the transmuscular quadratus lumborum (QL) block and the external oblique (EO) plane block, for pain relief after open nephrectomy. Open nephrectomy is a major surgical procedure that can cause significant postoperative pain and may require opioid medications for adequate pain control.

Adult patients undergoing open nephrectomy at the National Cancer Institute, Cairo University, who meet the study eligibility criteria will be randomly assigned to receive either a QL block or an EO plane block before surgery. Both techniques will be performed under ultrasound guidance using bupivacaine in addition to standardized general anesthesia and multimodal postoperative analgesia.

The main purpose of the study is to determine whether the QL block provides better postoperative analgesia than the EO plane block. The primary outcome will be the total amount of intravenous morphine consumed during the first 24 hours after surgery. Secondary outcomes will include postoperative pain scores, time to first request for rescue analgesia, hemodynamic changes, recovery time, patient satisfaction, and adverse effects related to analgesia or the regional anesthesia techniques.

A total of 54 patients will be enrolled and randomly allocated equally between the two treatment groups.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The study is a prospective, randomized clinical trial designed to compare the analgesic efficacy of the transmuscular quadratus lumborum block with the external oblique plane block in adult patients undergoing open nephrectomy.

Open nephrectomy is associated with substantial postoperative pain because of the extent of the surgical incision, muscular dissection, and manipulation of retroperitoneal structures. Effective postoperative analgesia is important to facilitate recovery, mobilization, respiratory function, and patient comfort while minimizing opioid requirements.

The quadratus lumborum block is a posterior abdominal wall fascial plane block in which local anesthetic is deposited in relation to the quadratus lumborum muscle. The technique may provide analgesia over several thoracoabdominal dermatomes and may have both somatic and visceral analgesic effects. The external oblique plane block is a more superficial fascial plane technique that targets the lateral abdominal wall and may provide effective somatic analgesia.

Eligible patients will be randomly allocated in a 1:1 ratio to receive either a transmuscular QL block or an EO plane block before induction of general anesthesia. All patients will receive standardized general anesthesia and multimodal postoperative analgesia. The regional blocks will be performed under ultrasound guidance by an experienced anesthesiologist.

The primary outcome is total intravenous morphine consumption during the first 24 postoperative hours. Secondary outcomes include pain intensity at predefined postoperative time points, both at rest and with movement; time to first request for rescue analgesia; intraoperative and postoperative hemodynamic changes; recovery time; patient satisfaction; and adverse effects, including nausea, vomiting, respiratory depression, and complications related to the regional anesthesia technique.

The study will evaluate whether the QL block provides superior postoperative analgesia and opioid-sparing effects compared with the EO plane block following open nephrectomy.

Study Type

Interventional

Enrollment (Estimated)

54

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

Adult patients aged 18 to 65 years. Patients undergoing open nephrectomy at the National Cancer Institute, Cairo University.

American Society of Anesthesiologists (ASA) physical status II-III. Body mass index (BMI) greater than 20 kg/m² and less than 35 kg/m².

Exclusion Criteria:

Patient refusal to participate. ASA physical status IV. Age less than 18 years or greater than 65 years. BMI less than 20 kg/m² or greater than 35 kg/m². Known allergy or contraindication to any study medication, including local anesthetics or opioids.

History of psychiatric disorders or chronic pain. Contraindications to regional anesthesia, including local infection at the injection site, pre-existing neuropathy, or coagulopathy.

Severe organ dysfunction, including cardiac dysfunction (ejection fraction <40%), respiratory dysfunction (FEV1 <50% of predicted or requirement for home oxygen therapy), hepatic dysfunction (Child-Pugh class C), or renal dysfunction (estimated glomerular filtration rate <30 mL/min/1.73 m²).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Quadratus Lumborum Block (QL)
Participants will receive an ultrasound-guided transmuscular quadratus lumborum block before induction of general anesthesia. A total of 30 mL of 0.25% bupivacaine will be administered in the fascial plane between the quadratus lumborum and psoas major muscles. Participants will also receive the standardized general anesthesia and postoperative multimodal analgesia described in the study protoco
Procedure: Quadratus Lumborum Block (QLB)
Ultrasound-guided transmuscular quadratus lumborum block using 30 mL of 0.25% bupivacaine administered before induction of general anesthesia.
Experimental: External Oblique Plane Block (EO)
Participants will receive an ultrasound-guided external oblique plane block before induction of general anesthesia. A total of 30 mL of 0.25% bupivacaine will be administered in the fascial plane between the external oblique and intercostal muscles. Participants will also receive the standardized general anesthesia and postoperative multimodal analgesia described in the study protocol.
Procedure: External Oblique Plane Block
Ultrasound-guided external oblique plane block using 30 mL of 0.25% bupivacaine administered before induction of general anesthesia.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
24-hour postoperative morphine consumption
Time Frame: First 24 hours after surgery
Total amount of intravenous morphine administered as rescue analgesia during the first 24 hours after surgery. Morphine consumption will be recorded for each participant and compared between the quadratus lumborum block and external oblique plane block groups.
First 24 hours after surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Cairo University

Investigators

  • Principal Investigator: Mona H Abdelhamid, MD, Professor of anesthesia

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 1, 2026

Primary Completion (Estimated)

April 1, 2027

Study Completion (Estimated)

May 1, 2027

Study Registration Dates

First Submitted

August 24, 2026

First Submitted That Met QC Criteria

August 24, 2026

First Posted (Actual)

August 26, 2026

Study Record Updates

Last Update Posted (Actual)

August 26, 2026

Last Update Submitted That Met QC Criteria

August 24, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • QL block vs EOB in nephrectomy

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared with other researchers because no data-sharing plan has been established for this study. Study data will be used by the research team for the purposes of the current study, in accordance with applicable ethical and institutional requirements.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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