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

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: Nephrolithiasis; Percutaneous Nephrolithotomy (PNL)
• Intervention / Treatment: Procedure: Erector spinae plane block (ESPB)

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

Study Locations

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

Participation Criteria

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

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
group 1; 0.25% Bupivacaine ESPB	Procedure: Erector spinae plane block (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	Procedure: Erector spinae plane block (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	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	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

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

Publications and helpful links

General Publications

• Forero M, Adhikary SD, Lopez H, Tsui C, Chin KJ. The Erector Spinae Plane Block: A Novel Analgesic Technique in Thoracic Neuropathic Pain. Reg Anesth Pain Med. 2016 Sep-Oct;41(5):621-7. doi: 10.1097/AAP.0000000000000451.
• Altiparmak B, Korkmaz Toker M, Uysal AI, Gumus Demirbilek S. Comparison of the efficacy of erector spinae plane block performed with different concentrations of bupivacaine on postoperative analgesia after mastectomy surgery: ramdomized, prospective, double blinded trial. BMC Anesthesiol. 2019 Mar 4;19(1):31. doi: 10.1186/s12871-019-0700-3.

Study record dates

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

• Keywords: bupivacaine; percutaneous nephrolithotomy; nephrolithiasis; erector spina plane block; different concentrations
• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urolithiasis; Nephrolithiasis
• 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