Kidney Week

Abstract: SA-PO566

Artificial Diuresis: Development of a Mathematical Model to Assess Ultrafiltration

Session Information

• Bioengineering
  October 26, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Bioengineering

• 400 Bioengineering

Authors

• Lorenzin, Anna, Department of Nephrology, Dialysis and Transplantation, San Bortolo Hospital, Vicenza, Italy

Anna Lorenzin, MS, MSc

• Brendolan, Alessandra, International Renal Research Institute of Vicenza (IRRIV), Vicenza, Italy

Alessandra Brendolan

• Ronco, Claudio, International Renal Research Institute of Vicenza (IRRIV), Vicenza, Italy

Claudio Ronco, MD

• Zanella, Monica, Department of Nephrology, Dialysis and Transplantation, San Bortolo Hospital, Vicenza, Italy

Monica Zanella, MD

Background

Fluid overload (FO) is associated with adverse outcome both in heart failure and critically ill patients admitted to intensive care. Extracorporeal ultrafiltration (UF) represents a solution to avoid acute kidney injury due to FO; an UF miniaturized device AD1 has been developed. Reduced priming volume, low pressures and flows at which it operates make AD1safer and smaller than the conventional machines. AD1 has been already tested in vitro and in animal studies, no adverse events have been reported.
The aim of this study was to develop an UF mathematical formulation capable to mimic the UF behaviour of AD1. Data collected from the animal study were used to validate the model.

Methods

AD1 is equipped with a peristaltic pump for blood flow (Q_b) and a polysulfone mini-filter. Transmembrane pressure (TMP) is modulated by Q_b setting and the height at which is hanging the bag for UF. This generate a negative pressure in the filter UF compartment: higher is the gap between AD1 and the bag, greater the negative pressure, increasing TMP and ultrafiltration rate (Q_UF).
In animal study, 6h UF sessions were scheduled in 3 pigs with a Q_b=30mL/min and the bag placed 20cm below AD1. Clinical parameters and UF data were collected.
The UF mathematical formulation is based on hydrostatics and hydrodynamics laws. Parameters considered are Q_b, height of the bag, haematocrit, catheter features. Experimental data were compared with the formulation.

Results

In the animal sessions the Q_UF was in a range of 3-5ml/min. Average data of target Q_UF, observed Q_UF during the animal study and the model estimation are reported. In all treatments the Q_UF was obtained in the absence of major clinical or technical problems with a maximum deviation from the target Q_UF lower than 10%. Formulation reported a maximum error compared to the experimental data less than 10%.

Conclusion

The model reported data comparable with the results observed in the animal study. The selected parameters and the implementation adequately estimate the Q_UF in the animal model. Data derived from clinical trials will be necessary to further assess and improve the model.