Venous Return Pressure Gradient as a Predictor of Acute Kidney Injury (VRPG-AKI)

July 22, 2026 updated by: Rongan Liu, Sichuan Academy of Medical Sciences

Venous Return Pressure Gradient Predicts Acute Kidney Injury Onset and Progression

Acute kidney injury (AKI) is a common and serious complication in the ICU. Current diagnostic indicators (such as creatinine and urine output) exhibit significant lag, and specific hemodynamic predictive markers are lacking. The venous return pressure gradient (Pmsf-CVP), based on Guyton's theory, reflects the driving pressure for venous return; however, its value in the early warning of AKI remains unclear. This study aims to investigate the predictive value of the venous return pressure gradient for the onset and progression of AKI in ICU patients, and to clarify its effectiveness as an AKI risk warning indicator.

Patients admitted to the ICU within 48 hours with risk factors for AKI (including sepsis, shock, major surgery, underlying diseases, etc.) who have radial artery catheterization and can undergo hemodynamic monitoring will be enrolled. Those undergoing maintenance dialysis/CRRT, ECMO support, or with missing core data precluding calculation of Pmsf-CVP or AKI assessment will be excluded.

The venous return pressure gradient (Pmsf-CVP, mmHg) will be measured within 48 hours of ICU admission using the transient stop-flow arm arterial-venous equilibrium pressure method. The primary outcome is to evaluate the association between the venous return pressure gradient level and AKI occurrence. Secondary outcomes include correlation analyses between the venous return pressure gradient level and serum creatinine and urine output within 48 hours of ICU admission, among others.

Study Overview

Status

Not yet recruiting

Intervention / Treatment

Study Type

Observational

Enrollment (Estimated)

180

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

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

Adult ICU patients (age ≥18 years) at risk for acute kidney injury, with central venous and radial arterial catheters in place for hemodynamic monitoring, no AKI at ICU admission per KDIGO criteria, and complete data available for calculation of venous return pressure gradient (Pmsf-CVP) within 48 hours of admission.

Description

Inclusion Criteria:

  1. Age ≥18 years
  2. Admitted to the intensive care unit (ICU) within 48 hours
  3. Central venous catheter in place for continuous central venous pressure (CVP) monitoring
  4. Radial artery catheter in place for hemodynamic monitoring including mean systemic filling pressure (Pmsf)
  5. No acute kidney injury (AKI) at ICU admission according to KDIGO criteria

Exclusion Criteria:

  1. Maintenance hemodialysis or continuous renal replacement therapy (CRRT) prior to ICU admission
  2. Previous kidney transplantation
  3. Pregnancy
  4. Extracorporeal membrane oxygenation (ECMO) support at ICU admission
  5. Incomplete core hemodynamic data precluding calculation of venous return pressure gradient (Pmsf-CVP) or AKI assessment

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

Outcome Measure
Measure Description
Time Frame
Acute Kidney Injury occurrence
Time Frame: Within 48 hours of ICU admission
Occurrence of acute kidney injury diagnosed according to KDIGO criteria (serum creatinine increase ≥1.5 times baseline, or ≥26 μmol/L within 48 hours, or urine output <0.5 mL/kg/h for ≥6 hours) during the ICU stay. The association between venous return pressure gradient (Pmsf-CVP, measured within the first 48 hours of ICU admission using the Pmsf-arm method) and AKI occurrence will be assessed by multivariable logistic regression analysis, adjusting for APACHE II score, baseline serum creatinine, lactate, mean arterial pressure, sepsis, and shock.
Within 48 hours of ICU admission

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Persistent Acute Kidney Injury
Time Frame: Within 48 hours after AKI occurrence during the ICU stay
Persistent AKI defined as failure of renal function to return to baseline within 48 hours after AKI occurrence during the ICU stay. The predictive value of venous return pressure gradient (Pmsf-CVP) for persistent AKI will be evaluated by ROC curve analysis.
Within 48 hours after AKI occurrence during the ICU stay
AKI severity grade
Time Frame: At the time of maximum AKI stage during the ICU stay, up to 28 days
Maximum AKI stage (KDIGO stage 1, 2, or 3) achieved during the ICU stay.
At the time of maximum AKI stage during the ICU stay, up to 28 days
In-hospital mortality
Time Frame: From ICU admission to hospital discharge, up to 90 days
All-cause mortality during the index hospitalization.
From ICU admission to hospital discharge, up to 90 days
Total length of hospital stay
Time Frame: From hospital admission to discharge or death, up to 90 days
Number of days from hospital admission to hospital discharge or in-hospital death, whichever comes first. Patients still hospitalized at day 90 will be censored at 90 days.
From hospital admission to discharge or death, up to 90 days
Correlation between venous return pressure gradient and serum creatinine
Time Frame: Within 48 hours of ICU admission
Spearman rank correlation analysis between Pmsf-CVP (measured within 48 hours of ICU admission) and serum creatinine levels (baseline creatinine at ICU admission and peak creatinine during ICU stay).
Within 48 hours of ICU admission
Correlation between venous return pressure gradient and lactate
Time Frame: Within 48 hours of ICU admission
Spearman rank correlation analysis between Pmsf-CVP (measured within 48 hours of ICU admission) and lactate levels obtained from the first arterial blood gas analysis within 48 hours of ICU admission.
Within 48 hours of ICU admission
Duration of mechanical ventilation
Time Frame: From intubation to first successful extubation
Number of days on invasive mechanical ventilation from the time of first intubation to the first successful extubation. Reintubation within 48 hours will be counted as continuous ventilation.
From intubation to first successful extubation
Length of ICU stay
Time Frame: From ICU admission to ICU discharge
Number of days from ICU admission to ICU discharge.
From ICU admission to ICU discharge

Collaborators and Investigators

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

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 (Estimated)

July 5, 2026

Primary Completion (Estimated)

May 1, 2027

Study Completion (Estimated)

May 1, 2027

Study Registration Dates

First Submitted

June 30, 2026

First Submitted That Met QC Criteria

July 22, 2026

First Posted (Actual)

July 23, 2026

Study Record Updates

Last Update Posted (Actual)

July 23, 2026

Last Update Submitted That Met QC Criteria

July 22, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

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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