Optimization of Fluid Balance Guided by Bioelectrical Impedance Analysis in Patients Undergoing Continuous Renal Replacement Therapy in Critical Care (OBHIMER)

In critical care, hemodynamic instability often requires volume expansion to restore tissue perfusion, increasing fluid balance and TBW, factors associated with higher mortality. Excess fluid leads to organ dysfunction due to venous congestion, making fluid removal crucial. When diuretics fail, RRT, typically through continuous renal replacement therapy (CRRT), is recommended. However, prescribing the correct level of UF is challenging; insufficient UF can worsen edema, while excessive UF risks hemodynamic instability. This pilot, single-center, prospective, interventional, randomized, controlled, open-label study includes two parallel groups: a standard group with UF prescribed by the physician based on clinical and hemodynamic status and an experimental group with UF guided by the extracellular to total body water (ECW/TBWat) ratio measured by BIA. The aim is to determine if ECW/TBW-guided UF improves fluid and TBW reduction over a 72-hour RRT period.

Study Overview

• Status: Recruiting
• Conditions: Congestion; Fluid Removal; RRT; UF; Bio-impendance Analysis; Diuretics; Overload
• Intervention / Treatment: Procedure: continuous renal replacement therapy (CRRT); Other: Free UF Prescription

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Christophe Beyls, MD; Phone Number: 33 + 03 22 08 78 66; Email: beyls.christophe@chu-amiens.fr

Study Locations

• France
  • Salouel, France, 80480
    • Recruiting
    • CHRU Amiens
    • Contact: Christophe Beyls, MD; Phone Number: 33 + 03 22 08 78 66; Email: beyls.christophe@chu-amiens.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age > 18 years
• The patient was hospitalized in the intensive care unit of Amiens-Picardie University Hospital.
• Patient with an increase in fluid balance (TBW > 5%)
• Patient receiving continuous veno-venous hemofiltration (CVVH) on a PrismaFlexR or PrisMaxR machine, initiated due to oliguria, potassium level > 6.5 mmol/L, urea level > 25 mmol/L, or creatinine > 300 µmol/L and severe metabolic acidosis (pH < 7.2).
• Hemodynamically stable patient with a mean arterial pressure (MAP) > 65 mmHg for more than 4 hours with norepinephrine.
• Signed consent to participate in the study by the patient or, if unconscious, their legal representative/next of kin.

Exclusion Criteria:

• Invalid BIA measurements
• Internal device powered by an electrical current (pacemaker, implantable cardioverter-defibrillator, neurostimulator)
• Cardiac arrhythmia (atrial fibrillation, atrial flutter) present at the inclusion
• Chronic dialysis patient
• Moribund patient
• The patient is on extracorporeal mechanical support
• Hemorrhagic shock
• Pregnant woman
• Patient under guardianship or conservators.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Free UF Prescription; Free UF Prescription : The UF (ml/h) is prescribed by the responsible physician based on the patient's clinical, congestive, and hemodynamic status. The physician can implement the UF whenever necessary based on the patient's hemodynamic condition.	Procedure: continuous renal replacement therapy (CRRT); The patient is included in the study once they meet the eligibility criteria and as soon as the responsible physician has prescribed RRT according to the department's protocol. Randomization will be performed, and the patient will be assigned to either the standard or experimental groups.
Experimental: UF Prescription Guided by the ECW/TBWat Ratio; Experimental Group - UF Prescription Guided by the ECW/TBWat Ratio : In the experimental group, the patient will receive a prescription for UF guided by the ECW/TBWat ratio. The goal is to achieve an ECW/TBWat ratio of less than 0.400 by the end of the 72-hour RRT session.; To meet this objective, the physician must measure the ECW/TBWat ratio each time the UF is adjusted. If the patient's ECW/TBWat ratio is less than 0.400 at the measurement time, the goal is to maintain it below 0.400 during the RRT session.; To calculate the ECW/TBWATratio, the Inbody BWA 2.0 device requires the initial TBW, which will be measured by the Hill-Room Acella 900 bed (Hill-Room, Batesville, USA).; The ratio is calculated by the Inbody BWA 2.0 and is based on the average of 3 consecutive measurements.; The physician determines the prescription for adjusting the UF (ml/h) based on the patient's hemodynamic and clinical condition during the RRT session.	Other: Free UF Prescription; The UF (ml/h) is prescribed by the responsible physician based on the patient's clinical, congestive, and hemodynamic status. The physician can implement the UF whenever necessary based on the patient's hemodynamic condition.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
comparison of TBW between both groups	To assess the impact of UF prescription guided by the ECW/TBWat ratio on weight loss, a comparison of TBW (∆TBW) between the two groups will be conducted. The ∆TBW is the difference between the initial TBW at H0 and the TBW at H72.	at 72 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Variation of cumulative net UF	The net UF is the difference between the fluids removed by RRT and the replacement fluids infused before and after the RRT filter. The cumulative net UF is the UF measured from H0 to H72. The volume of UF and infused replacement fluid will be calculated using data extracted from the memory card of the RRT machine.	at 72 hours
Measurement of the net UF rate	Measurement of the net UF rate (ml/kg/h): The net UF rate is calculated as follows: cumulative net UF / (TBW at H0) x effective treatment duration during the 72 hours of the study. The treatment duration will be measured using data extracted from the memory card of the RRT machine.	at 72 hours
Measurement of the ECW/TBWATratio and its association with the VeXUS score	Measurement of the ECW/TBWATratio and its association with the VeXUS score at H0 . The VeXUS score is an echocardiographic score (ranging from 0 to 3) used to analyze venous congestion at the cardiac, renal, and hepatic levels.	day 0
Measurement of the ECW/TBWATratio and its association with the VeXUS score	Measurement of the ECW/TBWATratio and its association with the VeXUS score at H72 . The VeXUS score is an echocardiographic score (ranging from 0 to 3) used to analyze venous congestion at the cardiac, renal, and hepatic levels.	at 72 hours
Measurement of the ECW/TBWAT ratio	Measurement of the ECW/TBWATratio and its association with conventional right heart function parameters and those evaluated by speckle tracking at H0. The speckle tracking-based parameters used will measure: (a) Longitudinal displacement of the septal and lateral walls and right ventricular shortening; (b) Global longitudinal strain and free wall strain of the right ventricle and (c) Right atrial strain (reservoir, conduit, and contraction phases). The parameters will be measured offline using the QLAB 15.0 software (Philips Healthcare).	day 0
Measurement of the ECW/TBWAT ratio	Measurement of the ECW/TBWATratio and its association with conventional right heart function parameters and those evaluated by speckle tracking at H72. The speckle tracking-based parameters used will measure: (a) Longitudinal displacement of the septal and lateral walls and right ventricular shortening; (b) Global longitudinal strain and free wall strain of the right ventricle and (c) Right atrial strain (reservoir, conduit, and contraction phases). The parameters will be measured offline using the QLAB 15.0 software (Philips Healthcare).	72 hours
number of filters used in both groups	Reporting of complications related to RRT in both groups : number of filters used	at 24 hours
number of filters used in both groups	Reporting of complications related to RRT in both groups : number of filters used	at 48 hours
number of filters used in both groups	Reporting of complications related to RRT in both groups : number of filters used	at 72 hours
duration of use for each filter in both groups	complications related to RRT in both groups : duration of use for each filter in both groups	at 24 hours
duration of use for each filter in both groups	complications related to RRT in both groups : duration of use for each filter in both groups	at 48 hours
duration of use for each filter in both groups	complications related to RRT in both groups : duration of use for each filter in both groups	at 72 hours
Number of hypotensive episodes during dialysis	Number of hypotensive episodes during dialysis: A hypotensive episode is defined as a mean arterial pressure (MAP) < 65 mmHg for 1 minute, measured using hemodynamic monitoring	at 24 hours
Number of hypotensive episodes during dialysis	Number of hypotensive episodes during dialysis: A hypotensive episode is defined as a mean arterial pressure (MAP) < 65 mmHg for 1 minute, measured using hemodynamic monitoring	at 48 hours
Number of hypotensive episodes during dialysis	Number of hypotensive episodes during dialysis: A hypotensive episode is defined as a mean arterial pressure (MAP) < 65 mmHg for 1 minute, measured using hemodynamic monitoring	at 72 hours
Number of arrhythmias in both groups	Number of arrhythmias in both groups	at 24 hours
Number of arrhythmias in both groups	Number of arrhythmias in both groups	at 48 hours
Number of arrhythmias in both groups	Number of arrhythmias in both groups	at 72 hours
Number of arrhythmias with hemodynamic instability	Number of arrhythmias with hemodynamic instability	at 24 hours
Number of arrhythmias with hemodynamic instability	Number of arrhythmias with hemodynamic instability	at 48 hours
Number of arrhythmias with hemodynamic instability	Number of arrhythmias with hemodynamic instability	at 72 hours
Measurement of serum potassium	Measurement of serum potassium	at 24 hours
Measurement of serum potassium	Measurement of serum potassium	at 48 hours
Measurement of serum potassium	Measurement of serum potassium	at 72 hours
Measurement of serum phosphate	Measurement of serum phosphate	at 24 hours
Measurement of serum phosphate	Measurement of serum phosphate	at 48 hours
Measurement of serum phosphate	Measurement of serum phosphate	at 72 hours
Cumulative volume of crystalloid administration	Cumulative volume of crystalloid administration	at 72 hours
Cumulative volume of colloid administration	Cumulative volume of colloid administration	at 72 hours
Cumulative dose of norepinephrine administration	Cumulative dose of norepinephrine administration	at 72 hours
Duration of norepinephrine administration	Duration of norepinephrine administration	at 72 hours
Duration of mechanical ventilation	Duration of mechanical ventilation	at day 30
30-day mortality	30-day mortality	at day 30
Length of stay in intensive care	Length of stay in intensive care	at day 30
Length of stay at the hospital	Length of stay at the hospital	at day 30

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire, Amiens

Study record dates

Study Major Dates

• Study Start (Actual): September 26, 2024
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: November 12, 2024
• First Submitted That Met QC Criteria: January 28, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 28, 2025
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: diuretics; RRT; congestion; fluid removal; bio-impendance analysis; overload; UF
• Other Study ID Numbers: PI2022_843_0069

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