ESP Block for Postoperative Analgesia in URS Surgery (ESPURS)

February 17, 2026 updated by: Onur Baran, Namik Kemal University

Efficacy of Erector Spinae Plane Block in Flexible Ureterorenoscopy (URS) Surgery: A Randomized Controlled Trial

The goal of this clinical trial is to determine whether the erector spinae plane (ESP) block provides better pain relief after flexible ureterorenoscopy (URS) surgery compared to standard analgesia alone. Researchers want to know:

Does the ESP block reduce pain levels in the first 24 hours after surgery?

Does it lower the need for opioid pain medication?

Does it reduce the need for additional (rescue) pain treatment?

Does it decrease the likelihood of postoperative nausea and vomiting (PONV)?

Participants will be randomly placed into one of two groups:

ESP Block Group: Participants will receive an ESP block using 20 mL of 0.25% bupivacaine under ultrasound guidance before surgery.

Control Group: Participants will receive standard pain management without a nerve block.

All participants will receive general anesthesia during surgery and multimodal pain management after surgery. Researchers will compare pain scores, opioid use, rescue analgesic needs, and the occurrence of nausea and vomiting between the two groups.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Intervention Group (ESP Block): Patients will receive 20 mL of 0.25% bupivacaine (1:1 diluted with 0.5% bupivacaine) under ultrasound guidance at the T8-T10 level.

Control Group: No block will be performed, and patients will receive standard postoperative multimodal analgesia.

Procedure Description: The ESP block will be performed under sterile conditions with a high-frequency linear ultrasound probe. A 100-mm echogenic needle will be inserted in a cephalocaudal direction to deposit the local anesthetic deep to the erector spinae muscle at the transverse process level. The correct spread of the anesthetic will be confirmed via real-time ultrasound imaging.

All patients will receive standardized general anesthesia and multimodal analgesia.

Outcome measures include postoperative pain (NRS), opioid consumption, rescue analgesia requirement, and postoperative nausea and vomiting (PONV).

Study Type

Interventional

Enrollment (Actual)

70

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 Locations

  • Turkey (Türkiye)
      • Tekirdağ, Turkey (Türkiye), 59000
        • Tekirdağ Namık Kemal University Research Hospital

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:

Patients undergoing elective flexible ureterorenoscopy (URS).

Age: 18-65 years.

ASA I-II.

Willing to participate and provide written informed consent.

Exclusion Criteria:

BMI >35 kg/m².

Allergy to local anesthetics.

Coagulation disorders or use of anticoagulants.

Patients requiring emergency surgery.

Patients with infection at the ESP block site.

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: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: ESP Block Group
A regional anesthesia technique in which 20 mL of 0.25% bupivacaine is injected under ultrasound guidance at the T8-T10 level to provide postoperative pain relief.
Procedure: Erector Spinae Plane (ESP) Block
A regional anesthesia technique in which 20 mL of 0.25% bupivacaine is injected under ultrasound guidance at the T8-T10 level to provide postoperative pain relief.
No Intervention: Control Group
Patients will receive routine multimodal analgesia without an ESP block.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pain Intensity (Numeric Rating Scale - NRS)
Time Frame: 0, 2, 6, 12, 24 hours postoperatively.

The Numeric Rating Scale (NRS, 0-10) will be used to assess postoperative pain intensity. Participants will be asked to rate their pain on a scale from 0 to 10, where:

  • 0 = No pain
  • 10 = Worst possible pain
0, 2, 6, 12, 24 hours postoperatively.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Total Opioid Consumption (IV PCA Morphine Equivalent)
Time Frame: From 0 hours (postoperatively) to 24 hours postoperatively, assessed at 0, 2, 6, 12, and 24 hours.
Description: Total opioid consumption will be recorded in morphine milligram equivalents (MME) administered via IV patient-controlled analgesia (PCA).
From 0 hours (postoperatively) to 24 hours postoperatively, assessed at 0, 2, 6, 12, and 24 hours.
Postoperative Nausea and Vomiting (PONV)
Time Frame: From 0 hours (postoperatively) to 24 hours postoperatively, assessed at 0, 2, 6, 12, and 24 hours.
The incidence of postoperative nausea and vomiting (PONV) will be recorded, defined as nausea and/or vomiting requiring treatment with ondansetron IV.
From 0 hours (postoperatively) to 24 hours postoperatively, assessed at 0, 2, 6, 12, and 24 hours.
Pain-Free Duration
Time Frame: From the end of surgery until the first request for pain medication, assessed up to 24 hours postoperatively.
Pain-free duration is defined as the time from the end of surgery to the first request for analgesia (when the patient reports pain requiring medication).
From the end of surgery until the first request for pain medication, assessed up to 24 hours postoperatively.

Collaborators and Investigators

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

Sponsor

Namik Kemal University

Investigators

  • Principal Investigator: Ayhan Şahin, Assoc. Prof., Namik Kemal University

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

Helpful Links

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)

February 20, 2025

Primary Completion (Actual)

August 20, 2025

Study Completion (Actual)

August 20, 2025

Study Registration Dates

First Submitted

February 7, 2025

First Submitted That Met QC Criteria

February 13, 2025

First Posted (Actual)

February 14, 2025

Study Record Updates

Last Update Posted (Actual)

February 19, 2026

Last Update Submitted That Met QC Criteria

February 17, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • TNKU-URS001

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

product manufactured in and exported from the U.S.

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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