Abstract
The potential of convective solute transport for blood purification has been widely explored. New techniques (such as hemodiafiltration), based on a combination of diffusion and convection techniques, have been developed. Owing to the internal filtration/backfiltration (IF/BF) phenomenon, high-flux dialysis also relies on a convective component, which, however, is hard to quantify and thus optimize. In this work, we developed a mathematical model designed to supply the clinician with a quantification of the IF/BF fluxes taking place during high-flux dialysis. IF fluxes are predicted based on the machine settings and blood hematocrit/protein concentration. The hydraulic characteristics of commercial dialyzers were derived from bloodless bench tests. Moreover, an in vitro blood test was conducted on a 1.8 m2 polysulfone dialyzer using an established scintigraphic analysis, for verification of model prediction accuracy. Results of simulations show that the IF/BF rate is sensitive to the blood flow rate and (to a lesser extent) to the dialysate flow rate. Increasing net ultrafiltration rates resulted in parallel increases of direct filtration and simultaneous decreases of BF. IF/BF is rather influenced by blood composition, due to the complex dependence of oncotic pressure and blood viscosity upon hematocrit and plasma protein concentration. Simulation results showed an excellent agreement with the experimental results obtained with scintigraphy, with only a 3% prediction error. With respect to some previous works, this model is simpler in its theoretical approach. It allows implementation into a user-friendly software tool and might be used to predict the convective component in high-flux dialysis and possibly to optimize it.
| Original language | English |
|---|---|
| Pages (from-to) | 555-568 |
| Number of pages | 14 |
| Journal | Blood Purification |
| Volume | 24 |
| Issue number | 5-6 |
| DOIs | |
| Publication status | Published - Dec 2006 |
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Keywords
- Backfiltration
- Filtration, internal
- High-flux hemodialyzer
- Mathematical model
- Ultrafiltration
ASJC Scopus subject areas
- Nephrology
- Hematology
Cite this
A new semiempirical mathematical model for prediction of internal filtration in hollow fiber hemodialyzers. / Fiore, Gianfranco B.; Guadagni, Gualtiero; Lupi, Andrea; Ricci, Zaccaria; Ronco, Claudio.
In: Blood Purification, Vol. 24, No. 5-6, 12.2006, p. 555-568.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A new semiempirical mathematical model for prediction of internal filtration in hollow fiber hemodialyzers
AU - Fiore, Gianfranco B.
AU - Guadagni, Gualtiero
AU - Lupi, Andrea
AU - Ricci, Zaccaria
AU - Ronco, Claudio
PY - 2006/12
Y1 - 2006/12
N2 - The potential of convective solute transport for blood purification has been widely explored. New techniques (such as hemodiafiltration), based on a combination of diffusion and convection techniques, have been developed. Owing to the internal filtration/backfiltration (IF/BF) phenomenon, high-flux dialysis also relies on a convective component, which, however, is hard to quantify and thus optimize. In this work, we developed a mathematical model designed to supply the clinician with a quantification of the IF/BF fluxes taking place during high-flux dialysis. IF fluxes are predicted based on the machine settings and blood hematocrit/protein concentration. The hydraulic characteristics of commercial dialyzers were derived from bloodless bench tests. Moreover, an in vitro blood test was conducted on a 1.8 m2 polysulfone dialyzer using an established scintigraphic analysis, for verification of model prediction accuracy. Results of simulations show that the IF/BF rate is sensitive to the blood flow rate and (to a lesser extent) to the dialysate flow rate. Increasing net ultrafiltration rates resulted in parallel increases of direct filtration and simultaneous decreases of BF. IF/BF is rather influenced by blood composition, due to the complex dependence of oncotic pressure and blood viscosity upon hematocrit and plasma protein concentration. Simulation results showed an excellent agreement with the experimental results obtained with scintigraphy, with only a 3% prediction error. With respect to some previous works, this model is simpler in its theoretical approach. It allows implementation into a user-friendly software tool and might be used to predict the convective component in high-flux dialysis and possibly to optimize it.
AB - The potential of convective solute transport for blood purification has been widely explored. New techniques (such as hemodiafiltration), based on a combination of diffusion and convection techniques, have been developed. Owing to the internal filtration/backfiltration (IF/BF) phenomenon, high-flux dialysis also relies on a convective component, which, however, is hard to quantify and thus optimize. In this work, we developed a mathematical model designed to supply the clinician with a quantification of the IF/BF fluxes taking place during high-flux dialysis. IF fluxes are predicted based on the machine settings and blood hematocrit/protein concentration. The hydraulic characteristics of commercial dialyzers were derived from bloodless bench tests. Moreover, an in vitro blood test was conducted on a 1.8 m2 polysulfone dialyzer using an established scintigraphic analysis, for verification of model prediction accuracy. Results of simulations show that the IF/BF rate is sensitive to the blood flow rate and (to a lesser extent) to the dialysate flow rate. Increasing net ultrafiltration rates resulted in parallel increases of direct filtration and simultaneous decreases of BF. IF/BF is rather influenced by blood composition, due to the complex dependence of oncotic pressure and blood viscosity upon hematocrit and plasma protein concentration. Simulation results showed an excellent agreement with the experimental results obtained with scintigraphy, with only a 3% prediction error. With respect to some previous works, this model is simpler in its theoretical approach. It allows implementation into a user-friendly software tool and might be used to predict the convective component in high-flux dialysis and possibly to optimize it.
KW - Backfiltration
KW - Filtration, internal
KW - High-flux hemodialyzer
KW - Mathematical model
KW - Ultrafiltration
UR - http://www.scopus.com/inward/record.url?scp=33845920152&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33845920152&partnerID=8YFLogxK
U2 - 10.1159/000097079
DO - 10.1159/000097079
M3 - Article
C2 - 17124424
AN - SCOPUS:33845920152
VL - 24
SP - 555
EP - 568
JO - Blood Purification
JF - Blood Purification
SN - 0253-5068
IS - 5-6
ER -