An interventional study of Calculated Post-Filter Hematocrit and Measured Post-Filter Hematocrit in Continuous Renal Replacement Therapy, Renal Failure and Hemofilter Clotting, sponsored by Gwyndolyn M. Radford. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-12-19.
Sponsored by Gwyndolyn M. Radford · Not applicable, Interventional, and Other
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.
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.
1,995 studies on the registry are indexed under Renal Insufficiency; 173 are open to participants now.
This study's planned enrollment of 20 is below the median of 43 across 1,504 interventional studies indexed under Renal Insufficiency.
Browse Renal Insufficiency studies →This is the only study on the registry with Gwyndolyn M. Radford as lead sponsor.
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Exclusion Criteria:
All participants will receive the same "intervention" of both measuring and calculating post-filter hematocrit.
Other: Calculated Post-Filter Hematocrit · Other: Measured Post-Filter Hematocrit
using the formula: HCTpost=HCTpre/(FF(HCTpre-1)+1)
Measured from blood sample taken from CRRT machine
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.
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.
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.
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
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.
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.
Plan to share: No
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