Impact of Reducing the Dialysate Flow Rate in Chronic Hemodialysis on Dialysis Quality and Environmental Impact on Water Consumption (ReDeDia)

July 17, 2026 updated by: Assistance Publique Hopitaux De Marseille

Non-inferiority Study on the Efficacy of Hemodialysis With Dialysate Flow Rates of 400 mL/Min Versus 500 mL/Min in a Population of Patients Undergoing Chronic Hemodialysis. Impact of Reducing the Dialysate Flow Rate in Chronic Hemodialysis on Dialysis Quality and Environmental Impact on Water Consumption

In France, 60,000 patients are receiving renal replacement therapy via dialysis in 2022, 90% of whom are on hemodialysis. This technique is based on the principle of exchange across a membrane between the patient's blood and the dialysate. The goal is to purify the patient's blood as effectively as possible by removing all solutes that have accumulated due to kidney failure. The dialysate is produced from municipal water, which is treated through several processes (reverse osmosis, filtration) to produce ultrapure water. Water consumption at the La Conception Hospital center in Marseille, which conducts 37,000 sessions per year (64 hemodialysis stations), is estimated at 120 m³ of water per day, which is discharged into the sewer system after use. In France, this would correspond to an estimated total consumption of nearly one million m³ of drinking water per year. In the context of climate change, which will lead to a reduction in water resources, it is important to rethink all aspects of water consumption. The investigator's reflection is part of a growing awareness of the environmental impact of dialysis within a working group of the Francophone Society of Nephrology, Dialysis, and Transplantation: "Green Dialysis." The quality of clearance depends on blood flow and dialysate flow rate (Qd). The Qd was set at 500 mL/min based on earlier studies that showed this flow rate corresponded to maximum clearance of urea and the main toxic solutes. These studies were conducted at a time when dialysis membranes were less efficient. Today, the investigators use membranes with higher exchange efficiency. Despite this, the investigators have not reevaluated the appropriateness of a Qd of 500 mL/min. The quality criterion in dialysis is a balanced urea Kt/V measurement >1.2 for a 4-hour session (target set at 1.4 with certain "single-pool" dialysis machine measurement techniques). At the ivnestigator's center, the average urea Kt/V is 1.55 in "single-pool" mode. Reducing the Qd could be done without risk to patients, even if it leads to a decrease in urea Kt/V. A Colombian study with 5 years of follow-up demonstrates patient safety with a Qd of 400 mL/min (vs. 500 mL/min), with no difference in mortality or dialysis efficacy. The study population was not representative of chronic dialysis patients; 10% regained renal function, and the final analysis included only 25 of the 71 patients enrolled.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

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.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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.
Interventional

Enrollment (Estimated)

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.
250

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • France
      • Marseille, France
        • Assistance Publique - Hôpitaux de Marseille
        • Contact:

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

Description

Inclusion Criteria:

  • Age > 18 years
  • No decompensated psychiatric disorder, acute or decompensated somatic condition
  • Patients on hemodialysis for more than 3 months
  • Dialysis schedule: 3 times per week for 4 hours each session
  • Stable vascular access (arteriovenous fistula or tunneled central catheter)
  • Blood flow > 300 mL/min
  • Anuric (urine output < 500 mL/24 h)
  • Dialysis method: hemodialysis or hemodiafiltration

Exclusion Criteria:

  • Age < 18 years
  • Patient on dialysis for < 3 months
  • Unstable vascular access
  • Blood flow rate < 300 mL/min
  • Urine output > 500 mL/day
  • Dialysis technique: hemofiltration
  • Severe intercurrent condition (somatic or psychiatric)
  • Pregnant or breastfeeding patients.
  • Patients who are legally incapacitated, under guardianship, or under conservatorship

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: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Dialysate flow at 400mL/min
Other: Dialysate flow at 400mL/min
Dialysate flow fixed at 400mL/min for one month.
Active Comparator: Dialysate flow at 500mL/min
Other: Dialysate flow at 500mL/min
Dialysate flow fixed at 500mL/min for one month.

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
Mesure of Urea Kt/V
Time Frame: Day 0, Month 1
Mesure of Urea clearance by two blood samples, after dialysis minus before dialyse (of urea blood sample), at Day 0 and Month 1
Day 0, Month 1

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Mesure of Beta2-microglobulin clearance
Time Frame: Day 0, Month 1
Mesure of Beta2-microglobulin clearance by two blood samples, after dialysis minus before dialyse (of urea blood sample), at Day 0 and Month 1
Day 0, Month 1
Potassium rate before dialysis
Time Frame: Day 0, Month 1
Mesure of Potassium rate before dialysis (Blood sample), at Day 0 and Month 1
Day 0, Month 1
Phosphorus rate before dialysis
Time Frame: Day 0, Month 1
Mesure of Phosphorus rate before dialysis (Blood sample), at Day 0 and Month 1
Day 0, Month 1
Bicarbonate rate before dialysis
Time Frame: Day 0, Month 1
Mesure of bicarbonate rate before dialysis (Blood sample), at Day 0 and Month 1
Day 0, Month 1
Acid indol acetic dosage rate
Time Frame: Day 0, Month 1 - Only for patient in dialysis in Assistance Publique Hopitaux de Marseille
Blood sample before dialysis at Day 0 and Month 1
Day 0, Month 1 - Only for patient in dialysis in Assistance Publique Hopitaux de Marseille
Questionnaire The 5-level EQ-5D version (EQ-5D-5L)
Time Frame: Day 0, Month 1
Questionnaries Quality of life EQ-5D-5L for patients, at Day 0 and Month 1. Scale ranging from 0 to 100, higher scores mean a better outcome.
Day 0, Month 1
Questionnaire The Kidney Disease Quality of Life 36-item short form survey (KDQoL)
Time Frame: Day 0, Month 1
Questionnaries Quality of life for patients KDQoL, at Day 0 and Month 1. Scale ranging from 0 to 100, higher scores mean a better outcome.
Day 0, Month 1
Indoxyl sulfate dosing rate
Time Frame: Day 0, Month 1 - Only for patient in dialysis in Assistance Publique Hopitaux de Marseille
Blood sample before dialysis at Day 0 and Month 1
Day 0, Month 1 - Only for patient in dialysis in Assistance Publique Hopitaux de Marseille
Para cresyl sulfate dosage rate
Time Frame: Day 0, Month 1 - Only for patient in dialysis in Assistance Publique Hopitaux de Marseille
Blood sample before dialysis at Day 0 and Month 1
Day 0, Month 1 - Only for patient in dialysis in Assistance Publique Hopitaux de Marseille

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.
Assistance Publique Hopitaux De Marseille

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Aix Marseille Université

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)

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.
January 1, 2027

Primary Completion (Estimated)

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.
April 1, 2029

Study Completion (Estimated)

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.
October 1, 2029

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).
July 7, 2026

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.
July 17, 2026

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.
July 22, 2026

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.
July 22, 2026

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.
July 17, 2026

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.
July 1, 2026

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.
  • RCAPHM25_0445
  • 2025-A02924-45 (Other Identifier: ANSM)

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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