Two Bupivacaine Concentrations for Erector Spinae Plane Block in Percutaneous Nephrolithotomy (ESPB-PNL)

June 12, 2026 updated by: Said Sencer Güney, Ankara Education and Research Hospital

Effects of Two Different Bupivacaine Concentrations in Ultrasound-Guided Thoracic Erector Spinae Plane Block on Postoperative Pain and Inflammatory Biomarkers After Percutaneous Nephrolithotomy

People who undergo percutaneous nephrolithotomy (PNL), a procedure used to remove kidney stones, often experience pain after surgery. An ultrasound-guided erector spinae plane block (ESPB) is commonly used to help reduce this pain.

This study compares two different concentrations of bupivacaine, a local anesthetic medication, used during ESPB. Participants undergoing PNL will receive either 0.25% or 0.375% bupivacaine as part of their pain management.

Researchers will compare pain scores, the need for additional pain medication, and changes in blood markers related to inflammation after surgery. The aim of the study is to determine whether one concentration provides better pain control or influences the inflammatory response differently after PNL.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Percutaneous nephrolithotomy (PNL) is the standard treatment for large and complex renal stones. Despite its minimally invasive nature, postoperative pain remains an important clinical concern and may adversely affect recovery, mobilization, and patient satisfaction. Ultrasound-guided thoracic erector spinae plane block (ESPB) has been increasingly incorporated into multimodal analgesia protocols because of its simplicity, safety profile, and effectiveness in reducing postoperative pain.

The optimal concentration of bupivacaine for ESPB in patients undergoing PNL remains unclear. This study was designed to compare the effects of two different concentrations of bupivacaine (0.25% and 0.375%) administered during ultrasound-guided thoracic ESPB on postoperative pain control and inflammatory response following PNL.

Adult patients scheduled for elective PNL were enrolled. ESPB was performed at the T10 vertebral level under ultrasound guidance before surgery. Participants received 20 mL of either 0.25% or 0.375% bupivacaine. Standard perioperative anesthetic and postoperative analgesic protocols were applied to all participants.

The primary outcome was postoperative pain intensity assessed using Visual Analog Scale (VAS) scores at predefined postoperative time points. Secondary outcomes included intraoperative fentanyl consumption, postoperative tramadol consumption, patient-controlled analgesia requirements, postoperative nausea and vomiting, patient satisfaction, and perioperative changes in inflammatory biomarkers, including the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR).

Demographic characteristics, stone-related variables, operative data, and perioperative hemodynamic parameters were recorded. Statistical analyses were performed to compare postoperative pain outcomes, analgesic requirements, and inflammatory biomarker responses between the study groups.

Study Type

Observational

Enrollment (Actual)

60

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

    • Mamak
      • Ankara, Mamak, Turkey (Türkiye), 06420
        • Ankara Training and 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

Sampling Method

Non-Probability Sample

Study Population

The study population consisted of adult patients undergoing elective percutaneous nephrolithotomy (PNL) for renal stone disease at a single tertiary care center between July 2024 and March 2025. Eligible participants were 18-70 years of age, classified as American Society of Anesthesiologists (ASA) physical status I-III, and received ultrasound-guided thoracic erector spinae plane block (ESPB) as part of perioperative analgesic management. A total of 60 participants were included and prospectively followed throughout the postoperative period.

Description

Inclusion Criteria:

  • Age between 18 and 70 years.
  • Scheduled to undergo elective percutaneous nephrolithotomy (PNL).
  • American Society of Anesthesiologists (ASA) physical status I-III.
  • Received ultrasound-guided thoracic erector spinae plane block (ESPB) before surgery.
  • Willing and able to provide written informed consent.

Exclusion Criteria:

  • Inability to assess pain using the Visual Analog Scale (VAS).
  • Advanced cardiovascular disease.
  • Coagulopathy or bleeding disorders.
  • Opioid use disorder.
  • Body mass index (BMI) ≥ 40 kg/m².
  • Infection at the planned injection site.
  • Known allergy or hypersensitivity to bupivacaine, other local anesthetics, or study-related medications.
  • Withdrawal of consent during the study period.

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
group 1
0.25% Bupivacaine ESPB
Ultrasound-guided thoracic erector spinae plane block was performed at the T10 vertebral level before surgery by an experienced anesthesiologist. A total volume of 20 mL bupivacaine was administered. Participants received either 0.25% or 0.375% bupivacaine according to the study cohort. The block was used as part of a multimodal analgesia protocol for postoperative pain management following percutaneous nephrolithotomy.
group 2
0.375% bupivacaine ESPB
Ultrasound-guided thoracic erector spinae plane block was performed at the T10 vertebral level before surgery by an experienced anesthesiologist. A total volume of 20 mL bupivacaine was administered. Participants received either 0.25% or 0.375% bupivacaine according to the study cohort. The block was used as part of a multimodal analgesia protocol for postoperative pain management following percutaneous nephrolithotomy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative pain intensity assessed using the Visual Analog Scale (VAS) and total opioid consumption
Time Frame: 36 hours after surgery
Postoperative pain intensity was assessed using the Visual Analog Scale (VAS; 0-10), where higher scores indicate greater pain severity. Pain scores and Total intraoperative and postoperative opioid consumption were recorded at 1, 3, 6, 12, 24, and 36 hours after surgery.
36 hours after surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
inflammatory markers
Time Frame: 24 hours after surgery
Changes in neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio measured before surgery and at 12 and 24 hours after surgery.
24 hours after surgery

Collaborators and Investigators

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

Sponsor

Investigators

  • Study Chair: suna akın takmaz, proffessor doctor, University of Health Sciences, Ankara Training and Research Hospital, Ankara, Türkiye

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.

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)

July 1, 2024

Primary Completion (Actual)

March 18, 2025

Study Completion (Actual)

March 19, 2025

Study Registration Dates

First Submitted

June 12, 2026

First Submitted That Met QC Criteria

June 12, 2026

First Posted (Actual)

June 17, 2026

Study Record Updates

Last Update Posted (Actual)

June 17, 2026

Last Update Submitted That Met QC Criteria

June 12, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • E-24-130

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be made publicly available because the informed consent obtained from participants did not include permission for public data sharing, and data confidentiality and privacy will be maintained in accordance with institutional and ethical 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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