Related Experiment Video
Updated: May 30, 2025
04:36
Measurement of Tissue Oxygenation Using Near-Infrared Spectroscopy in Patients Undergoing Hemodialysis
Published on: October 2, 2020
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Are there any session-to-session changes in ventilation during a weekly hemodialysis cycle?
Mauro Pietribiasi1, John K Leypoldt1, Monika Wieliczko2
1Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Warsaw, Poland.
The International Journal of Artificial Organs
|January 31, 2025
Summary
Hemodialysis patients experience variable CO2 levels due to bicarbonate treatments. Accurately predicting CO2 and bicarbonate requires models that account for daily changes in respiration, not fixed parameters.
Area of Science:
- Nephrology
- Physiology
- Mathematical Modeling
Background:
- Intermittent bicarbonate supplementation in hemodialysis (HD) patients causes significant weekly variations in pre-dialytic partial pressure of CO2 (pCO2).
- Predictive models using fixed parameters may inaccurately forecast pCO2 and plasma bicarbonate concentration (C_Bic) due to this interdialytic variability.
Purpose of the Study:
- To assess the impact of incorporating dynamic respiratory parameters into mathematical models for predicting acid-base equilibrium during hemodialysis.
- To improve the accuracy of predicting pCO2 and C_Bic by accounting for weekly variations in minute ventilation (V_E) and net acid generation rate (G_H).
Main Methods:
- A numerical model of acid-base equilibrium during HD was applied to 24 chronic HD patients.
- The model utilized both fixed weekly parameters and dynamically estimated V_E and G_H for each interdialytic interval.
- Dialysances for bicarbonate and dissolved CO2 were independently estimated for each HD session.
Main Results:
- Model error significantly decreased when V_E and G_H were estimated piecewise throughout the week.
- V_E showed significant changes between HD sessions (p < 0.05) and strongly correlated with pre-dialytic pCO2 (ρ = -0.97).
- G_H changes were not statistically significant and weakly correlated with pre-dialytic C_Bic (ρ = -0.30).
Conclusions:
- Acid-base equilibrium is highly sensitive to respiratory regulation in HD patients.
- Models predicting pCO2 and C_Bic evolution during the HD cycle must incorporate dynamic changes in respiratory parameters for accuracy.
- Failure to account for respiration variability leads to significant prediction errors.
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