Do Dynamic Urinary Leukocyte and Nitrite Changes Improve Risk Prediction for Infectious Complications Following PCNL?

November 18, 2025 updated by: Junhao Zheng, The First Affiliated Hospital of Guangzhou Medical University

Dynamic Changes in Preoperative Urinary Leukocytes and Nitrite as Predictors of Infectious Complications After Percutaneous Nephrolithotomy

Background Percutaneous nephrolithotomy (PCNL) is widely recognized as the primary surgical approach for managing sizable and anatomically complex kidney stones., yet postoperative infection-related complications remain common and potentially severe. Preoperative urine culture plays an important role in perioperative antibiotic guidance but is limited by delayed reporting and suboptimal sensitivity. Urinalysis is simple, cost-effective, and repeatable; however, most existing studies focus on single static measurements and lack systematic evaluation of temporal trends.

Objective To evaluate the association between temporal changes in preoperative urinary white blood cells (WBC) and nitrite (NIT) and the risk of postoperative fever and urosepsis in patients undergoing PCNL.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Introduction

Urolithiasis represents one of the most frequently encountered disorders in urological practice, and its global incidence has been increasing steadily in recent years, making it a significant public health concern that not only impairs patients' quality of life while creating considerable financial strain and increasing demands on healthcare systems . Percutaneous nephrolithotomy (PCNL) is now the primary therapeutic option recommended by international guidelines for medium-to-large and complex renal calculi, owing to its proven efficacy, minimal invasiveness, and rapid recovery . However, unavoidable factors during this procedure-such as high-pressure irrigation, migration of stone fragments, and injury to the renal pelvic mucosa-may facilitate the translocation of bacteria and endotoxins into the bloodstream, thereby triggering postoperative infectious complications, particularly fever and urosepsis. These complications can significantly impair postoperative recovery and prognosis and may even pose life-threatening risks .

Currently, preoperative urine culture is routinely used to assess a patient's infectious status and to guide perioperative antibiotic administration. However, this method has certain limitations, including a prolonged turnaround time (48-72 hours), susceptibility to sampling contamination, and the intermittent nature of bacteriuria, which restrict its utility in rapid clinical decision-making. In contrast, urinalysis is an economical, convenient, and repeatable test that is widely applied in preoperative evaluation. Among its parameters, urinary white blood cells (WBC) detected by microscopy and urinary nitrite (NIT) can serve as indirect indicators of urinary tract infection. Previous studies have demonstrated that preoperative WBC or NIT positivity is significantly associated with postoperative infectious complications following PCNL. A meta-analysis involving 6,113 patients reported that preoperative WBC positivity (OR ≈ 3.86) and NIT positivity (OR ≈ 7.81) were both independent risk factors. However, most of these studies were based on a single measurement and lacked a systematic evaluation of preoperative dynamic trends.

On this basis, the present study proposes a new clinical question: Can the dynamic changes in preoperative urinalysis WBC and NIT serve as effective predictors of postoperative infection risk in patients undergoing PCNL? To address this, we prospectively collected urinalysis data at admission and immediately before surgery, stratified patients according to dynamic change patterns, and analyzed the associations with postoperative fever and urosepsis, with the aim of providing a reference for clinical risk stratification and individualized anti-infective strategies.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
346

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

  • China
    • GuangGong
      • Guangzhou, GuangGong, China, 510500
        • The First Affiliated Hospital of Guangzhou Medical University

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

This study was based on a prospectively maintained observational cohort of patients undergoing PCNL at the Department of Urology, The First Affiliated Hospital of Guangzhou Medical University, between March 2021 and July 2025

Description

Inclusion Criteria:

  • Age ≥ 18 years
  • Renal stone diameter ≥ 2 cm, or complex renal stones, or failure of extracorporeal shock-wave lithotripsy (ESWL)
  • American Society of Anesthesiologists (ASA) physical status class I or II
  • Positive outpatient midstream urine culture

Exclusion Criteria:

  • Age < 18 years
  • Fever on admission
  • Concomitant renal tumor; Active, symptomatic urinary tract infection
  • Use of antibiotics for other reasons within 1 month prior to admission
  • Preoperative indwelling ureteral stent, nephrostomy tube, or double-J stent
  • Uncontrolled diabetes mellitus
  • Chronic kidney disease stage IIIa or higher (eGFR < 60 mL/min/1.73 m²)
  • Ongoing immunosuppressive therapy; Simultaneous bilateral renal stone surgery
  • Severe comorbidities (e.g., respiratory or circulatory failure) that preclude anesthesia or surgery
  • Pregnancy or lactation

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

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Postoperative Fever
Time Frame: Within 7 days postoperatively
Postoperative Fever was identified when body temperature reached or exceeded 38.0 °C.
Within 7 days postoperatively
Urosepsis
Time Frame: Within 7 days postoperatively
Urosepsis was diagnosed according to the Sepsis-3 criteria: confirmed urinary tract infection and a Sequential Organ Failure Assessment (SOFA) score ≥ 2.
Within 7 days postoperatively

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
The First Affiliated Hospital of Guangzhou Medical University

Study record dates

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Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 1, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 30, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 15, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 18, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 20, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 20, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 18, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • GYFYZJH1015

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

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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