Phosphate Kinetic Models in Hemodialysis: A Systematic Review.

BACKGROUND

Understanding phosphate kinetics in dialysis patients is important for the prevention of hyperphosphatemia and related complications. One approach to gain new insights into phosphate behavior is physiologic modeling. Various models that describe and quantify intra- and/or interdialytic phosphate kinetics have been proposed, but there is a dearth of comprehensive comparisons of the available models. The objective of this analysis was to provide a systematic review of existing published models of phosphate metabolism in the setting of maintenance hemodialysis therapy.

STUDY DESIGN

Systematic review.

SETTING & POPULATION

Hemodialysis patients.

SELECTION CRITERIA FOR STUDIES

Studies published in peer-reviewed journals in English about phosphate kinetic modeling in the setting of hemodialysis therapy.

PREDICTOR

Modeling equations from specific reviewed studies.

OUTCOMES

Changes in plasma phosphate or serum phosphate concentrations.

RESULTS

Of 1,964 nonduplicate studies evaluated, 11 were included, comprising 9 different phosphate models with 1-, 2-, 3-, or 4-compartment assumptions. Between 2 and 11 model parameters were included in the models studied. Quality scores of the studies using the Newcastle-Ottawa Scale ranged from 2 to 11 (scale, 0-14). 2 studies were considered low quality, 6 were considered medium quality, and 3 were considered high quality.

LIMITATIONS

Only English-language studies were included.

CONCLUSIONS

Many parameters known to influence phosphate balance are not included in existing phosphate models that do not fully reflect the physiology of phosphate metabolism in the setting of hemodialysis. Moreover, models have not been sufficiently validated for their use as a tool to simulate phosphate kinetics in hemodialysis therapy.

Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.