This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Phosphate Kinetic Modeling (PKM)

This study has been completed.
Information provided by (Responsible Party):
Fresenius Medical Care North America Identifier:
First received: October 27, 2009
Last updated: August 14, 2014
Last verified: November 2010
Cardiovascular disease is a major cause of death in hemodialysis (HD) patients and is associated with widespread vascular calcification. There is a consensus that the chronic overload of calcium and phosphorus is a major factor in vascular calcification. Hyperphosphatemia, deleterious in dialysis patients, is aggressively monitored and treated. Phosphate binders - designed to bind dietary phosphate and thus prevent its absorption, are ubiquitous in the dialysis patient population, and calcium-based phosphate binders are often first line therapy because they are tolerated well by the patients and low in cost. Phosphate Kinetic Modeling (PKM) is a tool to help physicians manage a hemodialysis patient's phosphate level. Once a subject consents to participate in the study, the subject's dietary phosphate intake will be estimated and the appropriate dose of the phosphate binder calcium acetate (PhosLo) will be recommended accordingly. If necessary, the Ca++ concentration of the dialysate will be changed to remove any excess calcium absorbed as the result of an increase in the PhosLo prescription to control phosphorus.Ongoing recommendations regarding oral phosphate binders dialysate calcium will be made using a computer generated algorithm.

Condition Intervention
End Stage Renal Disease Hyperphosphatemia Other: Computer algorithm management of hyperphosphatemia

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Phosphate Kinetic Modeling

Resource links provided by NLM:

Further study details as provided by Fresenius Medical Care North America:

Primary Outcome Measures:
  • The primary outcome variable is the change in serum phosphorus between a baseline period and the final 4 months of the study period. [ Time Frame: 6 months ]

Enrollment: 190
Study Start Date: October 2009
Study Completion Date: April 2011
Primary Completion Date: October 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: PKM modeling with graphical report Other: Computer algorithm management of hyperphosphatemia
The PKM algorithm is a computer based program that calculates Phosphorus intake between dialysis, phosphorus reduction during dialysis treatment and daily oral phosphate binder intake compliance. Based on pre and post dialysis serum phosphorus levels, the algorithm makes recommendations in relation to dialysate calcium, oral phosphate binder use, and dietary counseling.

Detailed Description:

PKM consists of a set of validated and computerized algorithms to perform the following steps:

  1. Calculate calcium (Ca) and phosphorus (P) intake and absorption in individual patients as a function of the prescribed doses of Vitamin D analogues, protein catabolic rate (PCR) and dietary and binder Ca intakes.
  2. Calculate P removal between dialyses by P binders and P and Ca removal during dialysis from kinetic analysis of total P and Ca transport during dialysis based on dialyzer P and Ca transport coefficients and the levels of dialysate Ca and serum Ca and P.
  3. Thus from analysis of intake, absorption and removal the program can calculate net Ca and P balance in modeled patients.
  4. Calculate the dose of phosphate binder required to reduce the serum P to normal in patients with hyperphosphatemia.
  5. Calculate the dialysate Ca required to achieve zero calcium balance over complete dialysis cycles - the interdialytic interval and immediately succeeding dialytic interval.
  6. The program also computes a Phosphorus-Protein index (PPI, the total P removed divided by PCR, mg/gm/day) which provides a quantitative index of compliance with prescribed dietary P restriction and/or the prescribed dose of binders. If the PPI exceeds 18, the report indicates it is likely the patient is not in compliance with respect to prescribed diet and/or binder. It is hoped that this information will be valuable to guide semiquantitative evaluations of diet P and binder intakes in patients difficult to manage.

Patients will be modeled on a monthly basis from pre- and post-dialytic Ca, P, PCR and other routine data readily available such as blood and dialysate flow rates, fluid removal etc. A monthly report will be generated for the physician and staff by Norma Ofsthun, PhD containing the analyses and recommendations for any changes in therapy.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Age ≥ 18 years
  2. Thrice weekly hemodialysis with a dialysate Ca++ concentration (CdiCa) of 2.25 or 2.5 mEq/L
  3. Stable CdiCa of either 2.25 or 2.5 mEq/L for ≥ 4 weeks
  4. Dialysis vintage ≥ 6 months
  5. Current serum phosphorus ("month -1") > 5.5 mg/dL and average serum phosphorus month -1 to -3 > 5.5 mg/dL and average serum phosphorus month -1 to -6 > 5.5 mg/dL
  6. Patients currently prescribed calcium acetate (PhosLo) mono-therapy , sevelamer monotherapy, or a combination therapy of PhosLo plus sevelamer for phosphate binding
  7. Fresenius Optiflux F 160, 180 or 200 dialyzer

Exclusion Criteria:

  1. Parathyroidectomy
  2. iPTH < 50 pg/mL
  3. Dialysate potassium prescription other than 2 or 3 mmol/L Corrected serum Ca++ < 7.5 mg/dL
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01003223

United States, Massachusetts
Fresenius Medical Services
Waltham, Massachusetts, United States, 02451
Sponsors and Collaborators
Fresenius Medical Care North America
  More Information

Responsible Party: Fresenius Medical Care North America Identifier: NCT01003223     History of Changes
Other Study ID Numbers: NEIRB PKM 09-207
Study First Received: October 27, 2009
Last Updated: August 14, 2014

Keywords provided by Fresenius Medical Care North America:
CKD stage V

Additional relevant MeSH terms:
Kidney Failure, Chronic
Renal Insufficiency, Chronic
Renal Insufficiency
Kidney Diseases
Urologic Diseases
Phosphorus Metabolism Disorders
Metabolic Diseases processed this record on July 25, 2017