Effect of Varied Dialysate Bicarbonate Levels on Phosphate and Potassium Removal

Chronic Dialysis Patients Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01930370
• Other study ID #: 1000014657
• Status: Completed
• Phase: Phase 4
• First received: August 23, 2013
• Last updated: May 27, 2015
• Start date: March 2010
• Est. completion date: December 2014

Study information

• Verified date: May 2015
• Source: The Hospital for Sick Children
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Ethics Review Committee
• Study type: Interventional

Clinical Trial Summary

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

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 12
• Est. completion date: December 2014
• Est. primary completion date: July 2014
• Accepts healthy volunteers: No
• Gender: Both
• Age group: N/A to 18 Years

Eligibility

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 Design

Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Chronic Dialysis Patients

Intervention

Drug:
• Bicarbonate hemodialysis solution (low concentration)
One-week experimental session (3 dialysis treatments) with low dialysate bicarbonate (28 mmol/L)
• Bicarbonate hemodialysis solution (high concentration)
One-week experimental session with high dialysate bicarbonate (38 mmol/L)

Locations

Country	Name	City	State
Canada	The Hospital for Sick Children	Toronto	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
The Hospital for Sick Children

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Phosphate/Potassium Removal	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)	No
Primary	Phosphate/Potassium Removal	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)	No
Primary	Phosphate/Potassium Removal	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)	No
Primary	Phosphate/Potassium Removal	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)	No
Primary	Phosphate/Potassium Removal	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)	No
Primary	Phosphate/Potassium Removal	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)	No
Secondary	Plasma Phosphate Levels	Measurement of the biochemical (serum) parameters of Phosphate for each dialysis treatment	Baseline and Post Dialysis (4hours)	No
Secondary	Plasma Potassium Levels	Measurement of the biochemical (serum) parameters of Potassium for each dialysis treatment	Pre and Post Dialysis	No
Secondary	Total Plasma CO2 (bicarbonate)	Measurement of the biochemical (serum) parameters of CO2 (bicarbonate) for each dialysis treatment	Pre and Post Dialysis (0 and 4hours)	No
Secondary	Corrected Calcium Measurement	Biochemical measurement of the blood for corrected caclium (calcium and albumin) for each dialysis treatment	Pre and Post Dialysis (0 and 4hours)	No
Secondary	Dialysis Adequacy (Kt/ V)	Measurement of Blood urea will be performed for each dialysis treatment.	Pre and Post Dialysis (0 and 4hours)	No
Secondary	Dialysis Adequacy (Urea Reduction Ratio -URR)	Measurement of Blood urea will be performed for each dialysis treatment.	Pre and Post Dialysis (0 and 4hours)	No