Randomized Bioimpedance vs Clinical Methods in Guiding Ultrafiltration in Hemodialysis Patients

Study Overview
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Brief Summary
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The investigators developed a prospective, randomized, controlled trial to compare strict volume control using bioimpedance (using the BCM - Body Composition Monitor device) versus traditional clinical volume control in hemodialysis patients and the impact on mortality, hydration status, blood pressure values and arterial stiffness.

Detailed Description
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The investigators developed a randomized controlled study to compare exclusively bioimpedance guided ultrafiltration in hemodialysis patients versus traditional methods for volume assessment. The duration of the study was 3,5 years. During the first 2,5 years of the study all enrolled patients were randomized using a block randomization algorithm in two arms. In the interventional arm the post-dialysis dry weight was prescribed exclusively using the BCM device (Body Composition Monitor - Fresenius Medical Care, Germany). In the control arm dry weight assessment was done by traditional clinical methods. In both arms,during the intervention period (2,5 years) BCM measurements were performed every 3 months before dialysis, but only in the interventional arm the values were disclosed to the medical personnel and used to guide the dry weight and ultrafiltration volumes. In the control arm (clinical), both patients and caregivers were fully blinded from the BCM results. The BCM device measures for each patient an ideal dry weight interval ( +/- 1.1 kg). In the interventional arm, the prescribed dry weights of the patients were strictly maintained in the ideal weight interval (+/- 1.1 kg) proposed by the BCM device. Primary outcome was all cause-mortality compared in the strict bioimpedance arm versus the clinical (control) arm and was assessed at 2,5 years. Secondary end-points, assessed during the randomization period (2,5 years), were to compare blood pressure (determined pre dialysis), arterial stiffness and relative fluid overload (RFO = overhydration/ total body water), as measured by the BCM device. During the last year of the study, all patients were left free of any intervention, and only arterial stiffness was assessed a third time at 3,5 years.

Official Title
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Bioimpedance Versus Clinical Methods in Guiding Ultrafiltration in Hemodialysis Patients: a Randomized Trial

Conditions
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Haemodialyzed Patients, Volume Status

Intervention / Treatment
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* Other: Strict bioimpedance guided dry weight prescription


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: older than 18-year on chronic hemodialysis for more than 3 months Exclusion Criteria: - life expectancy of less than 1 year Presence of a condition that may interfere with the determination of dry weight using the Body Composition Monitor (R): severe ascites (decompensated liver failure) limb amputations cardiac stent, pacemaker or defibrillator hip prosthetic pregnancy mental deficiency (impossibility to give consent)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Clinical (control)<br>In the clinical arm, dry weight and ultrafiltration prescription were done exclusively using traditional clinical methods of volume assessment. | |
| Active Comparator: Bioimpedance arm<br>Strict bioimpedance guided dry weight prescription arm. All patients dry weights were permanently maintained in the dry weight interval recommended by the BCM device (+/- 1,1 kg); BCM measurements were performed every 3 months. | Other: Strict bioimpedance guided dry weight prescription<br>* Post dialysis patient dry weight was exclusively prescribed using the ideal weight measured by the BCM device (+/- 1.1 Kg).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| All cause mortality | We assessed all-cause mortality in the two arms of the study at the end of intervention period. | 2,5 years follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arterial stiffness | Arterial stiffness was evaluated by applanation tonometry, measuring pulse wave velocity, and was done with a SphygmoCor® device (AtCor Medical, Westmead, Sydney, Australia). Measurements were performed in both arms at baseline, end of intervention (2,5 years) and at the end of the study (3,5 years). | 3,5 years | 
| Blood pressure values | In both arms, blood pressure was measured predialysis every 3 months and noted as a mean of the previous 3 predialysis BP values. | 2,5 years | 
| Overhydration | Overhydration was evaluated in both arms of the study using the Body Composition Monitor (BCM device), every 3 months. Overhydration was quantified as Relative fluid overload (RFO = overhydration/ total body water - as measured by the BCM. | 2,5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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hemodialysis, fluid management, bioimpedance, mortality, arterial stiffness