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Effect of Dialysis Techniques on Blood Pressure and Cardiac Function During Dialysis

Not Applicable
Completed
Conditions
End Stage Renal Disease (ESRD)
Diastolic Dysfunction
Hemodiafiltration
Intradialytic Hypotension
Hemodialysis
Interventions
Device: standard hemodialysis
Device: low volume hemodiafiltration
Device: cool hemodialysis
Device: high volume hemodiafiltration
Registration Number
NCT03249532
Lead Sponsor
Amsterdam UMC, location VUmc
Brief Summary

Online hemodiafiltration confers a reduced mortality risk. However, it is not clear why HDF improved survival. To gain more insight in this issue, the effect of 4 dialysis techniques (differing in dialysate temperature and the absence/presence of convective clearance) on intradialytic hemodynamic stability and cardiac function will be investigated in a prospective cross over trial.

Detailed Description

Despite the use of high permeable dialyzers, which combine diffusive with convective clearance, the clinical outcome of hemodialysis (HD) patients remains poor. In post-dilution online hemodiafiltration (denoted further on as HDF) diffusive clearance is similar to HD, while the amount of convective transport is considerable increased. Recently, 4 randomized controlled trails have been published which compared HD with HDF. Although the results of the individual studies were inconclusive, a recent meta-analysis, using individual patient data of these studies, showed a superior outcome for patients treated with HDF. The largest mortality reduction was obtained in patients receiving the highest convection volume (high-volume HDF \[HV-HDF\] \>23 L/1.73 m2/session): all-cause mortality \[22% (95 % confidence interval \[CI\] 2-38)\], cardiovascular disease (CVD) mortality \[31% (95 % CI 0-53)\].

It is far from clear, however, why (HV)HDF is associated with an improved survival. Both long term and short term effects may be involved. With respect to the latter, the intra-dialytic removal of middle molecular weight (MMW) uremic retention products and a superior bio-incompatibility (BI) profile may play a role. In addition, treatment with HDF may induce less intra-dialytic hypotension (IDH) and less tissue injury. Enhanced removal of the MMW substance FGF23 may reduce the intra-dialytic acute phase reaction (APR), which is regarded a chief element of HD-induced BI. Other key components which may contribute to IDH and are supposed to be alleviated by HDF, include dialysis-induced hypoxia and intra-dialytic extracellular vesicle release. Patho-physiologically, IDH depends both on a decline in the circulating blood volume and an impaired response to hypovolaemia. As a result, venous return, cardiac output and peripheral vascular resistance are impaired. Since IDH is reduced by HD with cool dialysate (C-HD), thermal factors may play an important role.

Microcirculatory dysfunction is a prominent feature of HD patients. Since IDH occurs in 20-30% of the sessions, any interference with an already abnormal perfusion may further deteriorate the structure and function of vital organs, such as the brain, gut and heart. HD-associated cardiomyopathy, which is considered a model of repetitive organ ischemia-reperfusion injury, is superimposed on the cardiac changes resulting from the various inflammatory and metabolic derangements of pre-dialysis kidney disease. As measured by imaging techniques and biomarkers, HD induces a fall in cardiac perfusion and elicits tissue injury. While cardiac MRI is considered the reference method for LV quantification, intra-dialytic measurements can only be obtained in stable patients who can be safely transferred to the radiology department. Echocardiography, though, can be performed in all individuals at the bed-side, including hypotension-prone patients. Because of its superiority over standard echocardiography, especially with respect to diastolic (dys)function, speckle tracking echocardiography will be used in the present study.

As mentioned, the effect on long term survival is especially prominent when HV-HDF is applied. Theoretically, HV-HDF is also the preferred treatment to circumvent dialysis-induced IDH, and hence, to alleviate the repetitive intra-dialytic tissue damage. Therefore, the following hypotheses will be tested:

1. intra-dialytic hemodynamic stability is better preserved during HV-HDF as compared to standard (S)-HD, C-HD and low volume (LV)-HDF;

2. mainly as a result of a better intra-dialytic hemodynamic stability, the severity of organ injury, especially the heart, is least evident during HV-HDF;

3. the mechanism of a better preserved intra-dialytic hemodynamic stability during HV-HDF depends on its superior thermal balance and/or bio-incompatibility, clearance of MMW substances, or a combination of these items.

Worldwide, however, (HV)HDF is only limited available. Since intradialytic hemodynamic instability may contribute substantially to the poor clinical prospects of end-stage-kidney-disease (ESKD) patients, these individuals may benefit from each maneuver that minimizes the number and severity of intradialytic hypotensive episodes. Therefore, the question which of the comparator treatments \[(S)-HD, C-HD and LV-HDF\] has the best intradialytic hemodynamic stability, appears relevant as well.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
40
Inclusion Criteria
  • treatment with HD or HDF 3 x per week during at least 4 hours for at least 2 months
  • ability to understand study procedures
  • willingness to provide informed consent
  • single pool Kt/V urea (spKt/Vurea) ≥ 1.2
  • achievement of blood flow of ≥360 ml/min and/or convection volume of >23 Liter per treatment during the run-in phase
Exclusion Criteria
    • current age < 18 years
  • severe incompliance to dialysis procedure and accompanying prescriptions, especially frequency and duration of dialysis treatment
  • life expectancy < 3 months
  • participation in another clinical intervention trial

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
cool hemodialysishigh volume hemodiafiltrationprescription of dialysate temperature: 35.5 degrees celsius prescription of convection volume: 0 L
standard hemodialysishigh volume hemodiafiltrationprescription of dialysate temperature: 36.5 degrees celsius prescription of convection volume: 0 Liters (L)
low volume hemodiafiltrationstandard hemodialysisprescription of dialysate temperature: 36.5 degrees celsius prescription of convection volume: 15 L
standard hemodialysislow volume hemodiafiltrationprescription of dialysate temperature: 36.5 degrees celsius prescription of convection volume: 0 Liters (L)
cool hemodialysisstandard hemodialysisprescription of dialysate temperature: 35.5 degrees celsius prescription of convection volume: 0 L
low volume hemodiafiltrationcool hemodialysisprescription of dialysate temperature: 36.5 degrees celsius prescription of convection volume: 15 L
high volume hemodiafiltrationcool hemodialysisprescription of dialysate temperature: 36.5 degrees celsius prescription of convection volume: 25 L
standard hemodialysiscool hemodialysisprescription of dialysate temperature: 36.5 degrees celsius prescription of convection volume: 0 Liters (L)
cool hemodialysislow volume hemodiafiltrationprescription of dialysate temperature: 35.5 degrees celsius prescription of convection volume: 0 L
low volume hemodiafiltrationhigh volume hemodiafiltrationprescription of dialysate temperature: 36.5 degrees celsius prescription of convection volume: 15 L
high volume hemodiafiltrationlow volume hemodiafiltrationprescription of dialysate temperature: 36.5 degrees celsius prescription of convection volume: 25 L
high volume hemodiafiltrationstandard hemodialysisprescription of dialysate temperature: 36.5 degrees celsius prescription of convection volume: 25 L
Primary Outcome Measures
NameTimeMethod
intradialytic hypotensionup to 4 hours (= one dialysis treatment); assessed during 3 treatments on each modality

nadir in systolic blood pressure (SBP) of 90 mmHg for patient with predialysis SBP \<160mmHg and a nadir of 100 mmHg for patients with predialysis SBP ≥160 mmHg during treatment (blood pressure will be measured before and every 15 minutes after the start of dialysis during the treatment)

Secondary Outcome Measures
NameTimeMethod
diastolic dysfunction during treatmentup to 4 hours (= one dialysis treatment); assessed during 1 treatment on each modality

speckle tracking echocardiography will be performed before, after 60 minutes of dialysis and after and after 3,5 hours

Trial Locations

Locations (3)

St Antonius Ziekenhuis

🇳🇱

Nieuwegein, Utrecht, Netherlands

Niercentrum aan de Amstel

🇳🇱

Amstelveen, Netherlands

VUmc

🇳🇱

Amsterdam, Netherlands

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