The Effect of Bicarbonate Profiling in Dialysis Fluid on Phosphate Removal During Hemodialysis and Blood pH

Study Overview
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Brief Summary
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Hyperphosphatemia is still an unresolved problem among hemodialysis patients and significantly increases the risk of death from cardiovascular diseases. Research to date has not answered the question of whether dialysate bicarbonate concentration profiling can improve phosphate removal and its concentration without negative impact on the acid-base balance. This study addressed this issue. Twenty stable hemodialysis patients will enroll to a four-week study during which different dialysate bicarbonate concentration profiles will be used each week. Each patient will undergo the following profiles (one-week periods): Treatment A - stable dialysate bicarbonate concentration Dbic 35 mmol/L during the whole HD session, Treatment B - Dbic 35 mmol/L for the first two hours and Dbic 30 mmol/L for the next two hours and Treatment C - the opposite mid-HD change Dbic from 30 to 35 mmol/L and one week wash-out period between Treatment B and C. We will collect blood samples each hour during the session and one hour after HD completion.

Official Title
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The Effect of Bicarbonate Profiling in Dialysis Fluid on Phosphate Removal During Hemodialysis and Blood pH

Conditions
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Phosphorus Metabolism Disorders, Acid-Base Balance Disorder

Intervention / Treatment
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* Other: Group 1: B) Dbic 35 -30 mmol/L C) Dbic 30- 35 mmol/L
* Other: Group 2: C) Dbic 30 -35 mmol/L B) Dbic 35- 30 mmol/L


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: stable general condition hemodialysis more than 3 months Dialysis 3 times a week/ 4 hours +/- 20 minutes Dialysis with arterio-venous fistulas bicarbonate titer before hemodialysis 22-24 mmol/l Exclusion Criteria: diabetes mellitus cachexia inflamation processes usage of sevelamer last month utrafiltration during dialysis more than 2500 ml

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: Non-Randomized
Intervention Model: Single Group Assignment
Interventional Model Description: Blood acid-base and uremic solute levels were measured in twenty chronic HD patients during 4-hour treatments with A) constant Dbic of 35 mmol/L; B) Dbic of 35 mmol/L for the first two hours and 30 mmol/L for the second two hours; and C) Dbic of 30 mmol/L for the first 2 hours and 35 mmol/L later. Treatment interventions were fixed during a given week, arterial blood samples were obtained predialysis and every hour during the treatment, during the second and third treatments of the week.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Group 1: B) Dbic 35 -30 mmol/L C) Dbic 30- 35 mmol/L<br>Week 1 - a constant Dbic 35 mmol/L -Treatment A. Week 2 - Dbic 35 mmol/L for the first two hours followed by 30 mmol/L for the remainder of the treatment- Treatment B. Week 3 - a constant Dbic 35 mmol/L (wash-out period). Week 4 - Dbic 30 mmol/L for the first two hours followed by 35 mmol/L for the remainder of the treatment -Treatment C. | Other: Group 1: B) Dbic 35 -30 mmol/L C) Dbic 30- 35 mmol/L<br>* A change Dbic in a middle of hemodialysis<br>|
| Active Comparator: Group 2: C) Dbic 30- 35 mmol/L B) Dbic 35 -30 mmol/L<br>Week 1 - a constant Dbic 35 mmol/L -Treatment A. Week 2 - Dbic 30 mmol/L for the first two hours followed by 35 mmol/L for the remainder of the treatment- Treatment C. Week 3 - a constant Dbic 35 mmol/L (wash-out period). Week 4 - Dbic 35 mmol/L for the first two hours followed by 30 mmol/L for the remainder of the treatment -Treatment B. | Other: Group 2: C) Dbic 30 -35 mmol/L B) Dbic 35- 30 mmol/L<br>* A change Dbic in a middle of hemodialysis<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The blood phosphorus concentration change in hemodialysis patient | The blood phosphorus concentration change in hemodialysis patient using dialysate bicarbonate profiling | 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The maintaining the acid-base balance in accordance with applicable recommendations. |  | 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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phosphorus, hemodialysis, bicarbonate, acidosis, alkalosis