Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Warsaw, Poland.
PLoS One. 2023 Feb 24;18(2):e0282104. doi: 10.1371/journal.pone.0282104. eCollection 2023.
Acid-base regulation by the kidneys is largely missing in end-stage renal disease patients undergoing hemodialysis (HD). Bicarbonate is added to the dialysis fluid during HD to replenish the buffers in the body and neutralize interdialytic acid accumulation. Predicting HD outcomes with mathematical models can help select the optimal patient-specific dialysate composition, but the kinetics of bicarbonate are difficult to quantify, because of the many factors involved in the regulation of the bicarbonate buffer in bodily fluids. We implemented a mathematical model of dissolved CO2 and bicarbonate transport that describes the changes in acid-base equilibrium induced by HD to assess the kinetics of bicarbonate, dissolved CO2, and other buffers not only in plasma but also in erythrocytes, interstitial fluid, and tissue cells; the model also includes respiratory control over the partial pressures of CO2 and oxygen. Clinical data were used to fit the model and identify missing parameters used in theoretical simulations. Our results demonstrate the feasibility of the model in describing the changes to acid-base homeostasis typical of HD, and highlight the importance of respiratory regulation during HD.
肾脏对酸碱的调节在接受血液透析 (HD) 的终末期肾病患者中基本缺失。在 HD 过程中向透析液中添加碳酸氢盐，以补充体内的缓冲液并中和透析间期的酸积累。通过数学模型预测 HD 结果有助于选择最佳的个体化透析液组成，但由于涉及到许多因素来调节体液中的碳酸氢盐缓冲液，因此很难量化碳酸氢盐的动力学。我们实施了一个描述 HD 引起的酸碱平衡变化的溶解二氧化碳和碳酸氢盐传输的数学模型，以评估碳酸氢盐、溶解二氧化碳和其他缓冲液的动力学，这些缓冲液不仅在血浆中，而且在红细胞、间质液和组织细胞中；该模型还包括对二氧化碳和氧气分压的呼吸控制。使用临床数据拟合模型并确定理论模拟中使用的缺失参数。我们的结果表明，该模型在描述 HD 中典型的酸碱平衡变化方面具有可行性，并强调了 HD 期间呼吸调节的重要性。
