Effect of Varied Dialysate Bicarbonate Levels on Phosphate and Potassium Removal

May 27, 2015 updated by: Elizabeth Harvey, The Hospital for Sick Children

Effect of Varied Dialysate Bicarbonate Levels on Phosphate and Potassium Removal: A Pilot Study

Modeling of bicarbonate within the dialysate fluid, specifically a lower than standard concentration has been suggested in facilitating the removal of phosphate and potassium. To test this hypothesis, the study will use a cross-over study design to evaluate phosphate and potassium removal during dialysis by altering bicarbonate concentration in dialysis fluid (i.e. high bicarbonate, standard bicarbonate washout, low bicarbonate), and compare the effects of the different dialysate bicarbonate concentrations on the removal of phosphate and potassium during hemodialysis

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Elevation of blood phosphate levels in chronic dialysis patients is associated with increased mortality due to cardiovascular events, and if sustained leads to hyperactivity of parathyroid glands and renal bone disease. Similarly, increased calcium-phosphate product as a result of elevated levels of phosphate in the blood is an additional risk factor for vascular calcification. Elevated blood potassium levels is another major electrolyte disorder in patients with advanced renal disease which is potentially life threatening. Therefore control of blood phosphate and potassium levels is a fundamental component of treatment for end stage renal disease. Management of hyperelectrolyte levels in renal failure patients requires restriction of phosphate and potassium intake through dietary measures, promotion of excretion via GI tract through medication delivery (i.e. supplementary binders), and removal through dialysis. All these strategies come with limitations however, specifically adherence to dietary restrictions and medication compliance is poor due to lack of immediate repercussions, as well as the complex kinetics involved with removal via dialysis given the dependence on duration and frequency of dialysis whose manipulation is limited by time considerations for the patient and scheduling issues in the dialysis unit.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
12

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Toronto, Ontario, Canada, M5G 1X8
        • The Hospital for Sick Children

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

No older than 14 years (Child, Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients 0-18 years old
  • Patients receiving maintenance hemodialysis* for a total of 9-15 hours per week
  • Pre-dialysis serum potassium value between 4.0 and 6.5 mmol/L on the first day of the treatment protocol
  • Pre-dialysis serum phosphate value greater than low normal for age on the first day of the treatment protocol
  • Pre-dialysis serum bicarbonate (total CO2) value between 18 and 30 mmol/L on the first day of the treatment protocol
  • Pre-dialysis corrected calcium value between 1.80-2.85 mmol/L on the first day of the treatment protocol

Exclusion Criteria:

  • Hemodynamically unstable patients (requiring inotropes or midodrine for support).
  • Pre-dialysis potassium value < 4.0 or > 6.5 mmol/L on the first day of the treatment protocol
  • Pre-dialysis serum phosphate value less than low normal for age on the first day of the treatment protocol (i.e. hypophosphatemia)
  • Pre-dialysis serum bicarbonate (total CO2) value <18 or > 30 mmol/L on the first day of the treatment protocol
  • Pre-dialysis corrected calcium <1.8 and >2.85 mmol/L on the first day of the treatment protocol
  • Patients mechanically ventilated
  • Drugs that could modify internal phosphate and potassium balance such as insulin, bicarbonate injection, hypertonic dextrose solution or mannitol infusion during HD

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Hemodialysis patients
Each patient will be evaluated during a total of 3.5 weeks correlating to routine dialysis treatment appointments. Each participant will start with low bicarbonate, followed by the washout phase (standard bicarbonate), then high bicarbonate, finishing with the follow up period. Dialysis prescription is standardized for each patient throughout the entire 3.5 week study period.
Drug: Bicarbonate hemodialysis solution (low concentration)
One-week experimental session (3 dialysis treatments) with low dialysate bicarbonate (28 mmol/L)
Drug: Bicarbonate hemodialysis solution (high concentration)
One-week experimental session with high dialysate bicarbonate (38 mmol/L)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Phosphate/Potassium Removal
Time Frame: Dialysis Treatment 1 (Day 1) - Pre and Post dialysis (0hrs and 4hours)

The amount of phosphate/potassium removed with each dialysis as measured from dialysate aliquots and total calculated volume of dialysate. The following formula will be used to calculate Phosphate (PO4) and Potassium (K) mass removal (mmol/treatment):

Calculation based on the concentration of K/PO4 (mmol/L) in dialysate x (calculated volume of dialysate + calculated volume of ultrafiltrate)
Dialysis Treatment 1 (Day 1) - Pre and Post dialysis (0hrs and 4hours)
Phosphate/Potassium Removal
Time Frame: Dialysis Treatment 2 (Day 2) - Pre and Post dialysis (0hrs and 4hours)

The amount of phosphate/potassium removed with each dialysis as measured from dialysate aliquots and total calculated volume of dialysate. The following formula will be used to calculate Phosphate (PO4) and Potassium (K) mass removal (mmol/treatment):

Calculation based on the concentration of K/PO4 (mmol/L) in dialysate x (calculated volume of dialysate + calculated volume of ultrafiltrate)
Dialysis Treatment 2 (Day 2) - Pre and Post dialysis (0hrs and 4hours)
Phosphate/Potassium Removal
Time Frame: Dialysis Treatment 3 (Day 3) - Pre and Post dialysis (0hrs, 4hours, 5hours)

The amount of phosphate/potassium removed with each dialysis as measured from dialysate aliquots and total calculated volume of dialysate. The following formula will be used to calculate Phosphate (PO4) and Potassium (K) mass removal (mmol/treatment):

Calculation based on the concentration of K/PO4 (mmol/L) in dialysate x (calculated volume of dialysate + calculated volume of ultrafiltrate)
Dialysis Treatment 3 (Day 3) - Pre and Post dialysis (0hrs, 4hours, 5hours)
Phosphate/Potassium Removal
Time Frame: Dialysis Treatment 7 (Day 15) - Pre and Post dialysis (0hrs, 4hours)

The amount of phosphate/potassium removed with each dialysis as measured from dialysate aliquots and total calculated volume of dialysate. The following formula will be used to calculate Phosphate (PO4) and Potassium (K) mass removal (mmol/treatment):

Calculation based on the concentration of K/PO4 (mmol/L) in dialysate x (calculated volume of dialysate + calculated volume of ultrafiltrate)
Dialysis Treatment 7 (Day 15) - Pre and Post dialysis (0hrs, 4hours)
Phosphate/Potassium Removal
Time Frame: Dialysis Treatment 8 (Day 16) - Pre and Post dialysis (0hrs, 4hours)

The amount of phosphate/potassium removed with each dialysis as measured from dialysate aliquots and total calculated volume of dialysate. The following formula will be used to calculate Phosphate (PO4) and Potassium (K) mass removal (mmol/treatment):

Calculation based on the concentration of K/PO4 (mmol/L) in dialysate x (calculated volume of dialysate + calculated volume of ultrafiltrate)
Dialysis Treatment 8 (Day 16) - Pre and Post dialysis (0hrs, 4hours)
Phosphate/Potassium Removal
Time Frame: Dialysis Treatment 9 (Day 17) - Pre and Post dialysis (0hrs, 4hours, 5hours)

The amount of phosphate/potassium removed with each dialysis as measured from dialysate aliquots and total calculated volume of dialysate. The following formula will be used to calculate Phosphate (PO4) and Potassium (K) mass removal (mmol/treatment):

Calculation based on the concentration of K/PO4 (mmol/L) in dialysate x (calculated volume of dialysate + calculated volume of ultrafiltrate)
Dialysis Treatment 9 (Day 17) - Pre and Post dialysis (0hrs, 4hours, 5hours)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Plasma Phosphate Levels
Time Frame: Baseline and Post Dialysis (4hours)
Measurement of the biochemical (serum) parameters of Phosphate for each dialysis treatment
Baseline and Post Dialysis (4hours)
Plasma Potassium Levels
Time Frame: Pre and Post Dialysis
Measurement of the biochemical (serum) parameters of Potassium for each dialysis treatment
Pre and Post Dialysis
Total Plasma CO2 (bicarbonate)
Time Frame: Pre and Post Dialysis (0 and 4hours)
Measurement of the biochemical (serum) parameters of CO2 (bicarbonate) for each dialysis treatment
Pre and Post Dialysis (0 and 4hours)
Corrected Calcium Measurement
Time Frame: Pre and Post Dialysis (0 and 4hours)
Biochemical measurement of the blood for corrected caclium (calcium and albumin) for each dialysis treatment
Pre and Post Dialysis (0 and 4hours)
Dialysis Adequacy (Kt/ V)
Time Frame: Pre and Post Dialysis (0 and 4hours)
Measurement of Blood urea will be performed for each dialysis treatment.
Pre and Post Dialysis (0 and 4hours)
Dialysis Adequacy (Urea Reduction Ratio -URR)
Time Frame: Pre and Post Dialysis (0 and 4hours)
Measurement of Blood urea will be performed for each dialysis treatment.
Pre and Post Dialysis (0 and 4hours)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
The Hospital for Sick Children

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Denis Geary, MD, The Hospital for Sick Children

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 1, 2010

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2014

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2014

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 23, 2013

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 23, 2013

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 28, 2013

Study Record Updates

Last Update Posted (Estimate)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 28, 2015

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 27, 2015

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 1000014657

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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