Continuous Renal Replacement TherapyCRRTHCTNCT07293936
Post-Filter Hematocrit
A study testing Calculated Post-Filter Hematocrit and Measured Post-Filter Hematocrit in people with Continuous Renal Replacement Therapy and Renal Failure, run by Gwyndolyn M. Radford at 1 site in United States.
Trial summary
Filter clotting is a major complication of continuous renal replacement therapy (CRRT), resulting in blood loss, reduced treatment efficacy, and increased cost. One modifiable factor associated with filter clotting is filtration fraction (FF), or the proportion of plasma water being removed from the blood over the… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Continuous Renal Replacement Therapy, Renal Failure, Hemofilter Clotting
- What is being tested?
- Calculated Post-Filter Hematocrit and Measured Post-Filter Hematocrit
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Mar 2025to 15 Mar 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- patients initiated on CRRT age equal than or greater to 18 years of age
Who cannot join
- patients on ECMO
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Iowa Hospitals and Clinics
Iowa City, Iowa, 52242
Gwyndolyn M Radford, MD, 319-384-9668, gwyndolyn-radford@uiowa.edu
About this study
Official title: Validation of a Post-Filter Hematocrit Calculation Formula: A Comparative Analysis With Measured Post-Filter Hematocrit Values
Filter clotting is a major complication of continuous renal replacement therapy (CRRT), resulting in blood loss, reduced treatment efficacy, and increased cost. One modifiable factor associated with filter clotting is filtration fraction (FF), or the proportion of plasma water being removed from the blood over the course of the filter. In convention, a cutoff of FF<20-30% has been used to prevent hemofilter clotting, but no evidence correlating FF with hemofilter clotting has been documented. Some experts have proposed that post-filter hematocrit (Hct) could be a more direct marker for determining hemofilter clotting risk, but evidence supporting clinical utility of this marker is lacking.
HCTpost=HCTpre/(FF(HCTpre-1)+1)
Read more
In our proposed validation study, we hope to determine whether our formula for post-filter Hct provides accurate results when compared to measured values. The information obtained from this study will potentially justify the use of utilizing the formula in future studies.
The procedure of this study is collecting blood samples from the post-filter lines of patients on CRRT at different time points and different flow rates. This will be considered the "measured post-filter hematocrit" which will then be compared to the calculated formula above, using the other values obtained from daily labs (for pre-filter hematocrit) and CRRT machine settings.
Read the detailed description
This investigational study is listed as "other" because it is a validation study comparing two measurement methods-comparing a calculated versus a machine-measured post-filter hematocrit- and is typically classified as a cross-sectional investigational study in the context of diagnostic or method comparison research.
- Being tested
- Calculated Post-Filter Hematocrit, Measured Post-Filter Hematocrit
- Keywords
- crrt, continuous renal replacement therapy, hemofilter clotting, post-filter hematocrit, filtration fraction
- Medical subject headings
- Renal Insufficiency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Calculated Post-Filter HematocritOther
using the formula: HCTpost=HCTpre/(FF(HCTpre-1)+1)
Measured Post-Filter HematocritOther
Measured from blood sample taken from CRRT machine
| Study group | Role | What they receive |
|---|---|---|
| CRRT patients | Other | All participants will receive the same "intervention" of both measuring and calculating post-filter hematocrit. Receives: Other: Calculated Post-Filter Hematocrit; Other: Measured Post-Filter Hematocrit |
What is being measured
The primary outcome is the main question the study is designed to answer.
Agreement between measured and calculated post-filter hematocrit values.
Use Bland-Altman analysis to assess agreement and quantify bias and limits of agreement. Calculate correlation coefficients (Pearson or Spearman) to evaluate the strength of association.
Measured: Participation begins at consent and includes a single study procedure in which four post-filter blood samples are collected over ~40 minutes. Participation ends after the final draw. Generally, no longer than 1 day.
Secondary outcomes (2)
Analyze the impact of CRRT settings on discrepancies between measured and calculated Filtration Fraction
How do different settings (e.g., Q_B, Q_UF, Q_prefilter, Q_postfilter) on the machine affect the discrepancies (if there are any) between calculated and measured filtration fraction. Will be using change in post-filter hematocrit values as the measured filtration fraction and comparing to calculated filtration fraction using standard flow-rate derived formula used in practice.
Measured: Participation begins at consent and includes a single study procedure in which four post-filter blood samples are collected over ~40 minutes. Participation ends after the final draw. Generally, no longer than one day.
Subgroup analysis based on patient-specific factors
Post-filter hematocrit values will be stratified and compared across subgroups defined by baseline pre-filter hematocrit category, anticoagulation strategy (e.g., citrate vs. heparin vs. none), and blood-flow rate category. The metric reported will be the mean post-filter hematocrit within each subgroup and the between-group differences.
Measured: Participation begins at consent and includes a single study procedure in which four post-filter blood samples are collected over ~40 minutes. Participation ends after the final draw.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Dec 2025
- Study start15 Mar 2025
- Primary completion1 Feb 2026 (estimated)
- Study completion15 Mar 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Continuous Renal Replacement TherapyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- All participants will undergo the same "intervention" of both using their blood samples to measure post-filter hematocrit and using their other lab values and CRRT settings to calculate post-filter hematocrit.
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Gwyndolyn M. Radford
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Gwyndolyn M. Radford, University of Iowa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07293936
- Sponsor's protocol ID
- 202412294
- Acronym
- CRRTHCT
- Status last verified
- Dec 2025
- First submitted
- 4 Mar 2025
- Last updated
- 19 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Validation of a Post-Filter Hematocrit Calculation Formula: A Comparative Analysis With Measured Post-Filter Hematocrit Values
- ClinicalTrials.gov ID
- NCT07293936
- Acronym / sponsor ID
- CRRTHCT / 202412294
- Keywords
- crrt, continuous renal replacement therapy, hemofilter clotting, post-filter hematocrit, filtration fraction
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Gwyndolyn M. RadfordUniversity, hospital or other
- Study start
- 15 Mar 2025 (actual)
- Primary completion
- 1 Feb 2026 (estimated)
- Study completion
- 15 Mar 2026 (estimated)
- First posted
- 19 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Filter clotting is a major complication of continuous renal replacement therapy (CRRT), resulting in blood loss, reduced treatment efficacy, and increased cost. One modifiable factor associated with filter clotting is filtration fraction (FF), or the proportion of plasma water being removed from the blood over the course of the filter. In convention, a cutoff of FF<20-30% has been used to prevent hemofilter clotting, but no evidence correlating FF with hemofilter clotting has been documented. Some experts have proposed that post-filter hematocrit (Hct) could be a more direct marker for determining hemofilter clotting risk, but evidence supporting clinical utility of this marker is lacking.
HCTpost=HCTpre/(FF(HCTpre-1)+1)
In our proposed validation study, we hope to determine whether our formula for post-filter Hct provides accurate results when compared to measured values. The information obtained from this study will potentially justify the use of utilizing the formula in future studies.
The procedure of this study is collecting blood samples from the post-filter lines of patients on CRRT at different time points and different flow rates. This will be considered the "measured post-filter hematocrit" which will then be compared to the calculated formula above, using the other values obtained from daily labs (for pre-filter hematocrit) and CRRT machine settings.
Detailed description
This investigational study is listed as "other" because it is a validation study comparing two measurement methods-comparing a calculated versus a machine-measured post-filter hematocrit- and is typically classified as a cross-sectional investigational study in the context of diagnostic or method comparison research.
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- All participants will undergo the same "intervention" of both using their blood samples to measure post-filter hematocrit and using their other lab values and CRRT settings to calculate post-filter hematocrit.
| Arm | Type | Receives |
|---|---|---|
| CRRT patients | Other | Other: Calculated Post-Filter Hematocrit, Other: Measured Post-Filter HematocritAll participants will receive the same "intervention" of both measuring and calculating post-filter hematocrit. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- patients initiated on CRRT age equal than or greater to 18 years of age
Key exclusion criteria (1 listed)
- patients on ECMO
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Calculated Post-Filter Hematocritusing the formula: HCTpost=HCTpre/(FF(HCTpre-1)+1) | Other | CRRT patients |
| Measured Post-Filter HematocritMeasured from blood sample taken from CRRT machine | Other | CRRT patients |
Primary outcome
Agreement between measured and calculated post-filter hematocrit values.
Time frame: Participation begins at consent and includes a single study procedure in which four post-filter blood samples are collected over ~40 minutes. Participation ends after the final draw. Generally, no longer than 1 day.
Use Bland-Altman analysis to assess agreement and quantify bias and limits of agreement. Calculate correlation coefficients (Pearson or Spearman) to evaluate the strength of association.
2 secondary outcomes
Analyze the impact of CRRT settings on discrepancies between measured and calculated Filtration Fraction
Time frame: Participation begins at consent and includes a single study procedure in which four post-filter blood samples are collected over ~40 minutes. Participation ends after the final draw. Generally, no longer than one day.
Subgroup analysis based on patient-specific factors
Time frame: Participation begins at consent and includes a single study procedure in which four post-filter blood samples are collected over ~40 minutes. Participation ends after the final draw.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Dec 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Calculated Post-Filter Hematocrit and Measured Post-Filter Hematocrit in people with Continuous Renal Replacement Therapy and Renal Failure, run by Gwyndolyn M. Radford at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 19 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Gwyndolyn M Radford, MD (7858179620, gradford@uiowa.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Agreement between measured and calculated post-filter hematocrit values. (time frame: Participation begins at consent and includes a single study procedure in which four post-filter blood samples are collected over ~40 minutes. Participation ends after the final draw. Generally, no longer than 1 day.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Dec 2025.