Department of Clinical Engineering, Faculty of Health Care, Jikei University of Health Care Sciences, Osaka, Japan.
Department of Clinical Engineering, Miyamoto Clinic, Hyogo, Japan.
Blood Purif. 2024;53(6):505-510. doi: 10.1159/000536073. Epub 2024 Feb 4.
Continuous monitoring of relative blood volume (percentage BV) in hemodialysis (HD) is critical for determining dry weight and preventing intradialytic hypotension. However, the cause of the BV variation remains unknown. This research aimed to examine factors that influence the percentage BV.
We devised a formula based on coefficients ("a," "τ," and "b") to predict changes in percentage BV. "a" denotes a significant decrease in percentage BV in the early stages of HD. "τ" represents the transition from early to late phase of HD. "b" denotes the slope of the decrease in percentage BV in the late phase of HD. We measured the percentage BV in 18 patients with end-stage renal disease. The coefficients were estimated by fitting experimental data from patients using a least squares optimization algorithm. A correlation analysis of these parameters and patient predialysis data was performed.
Ultrafiltration rate (UFR) was found to be negatively correlated with "b" (r = -0.851, p < 0.01). However, UFR was not significantly related to "a." Predialysis serum total protein level was negatively correlated with "a" (r = -0.531, p = 0.042). Predialysis serum albumin and predialysis sodium were not significantly correlated with "a" and "τ." Plasma osmolarity did not have a significant relationship with "a" and "τ."
DISCUSSION/CONCLUSION: UFR influenced the decrease in percentage BV in the late phase but did not influence the decrease of percentage BV in the early phase. "a" was associated with predialysis serum total protein level but not with plasma osmolality or predialysis sodium. This implies that colloid oncotic pressure is important for plasma refilling immediately after dialysis begins. During the change of percentage BV, the decrease in the early phase of dialysis was not related to UFR, but related to other parameters, especially predialysis total protein level. A decrease in the late phase of dialysis is related to UFR.
在血液透析（HD）中连续监测相对血容量（BV%）对于确定干重和预防透析中低血压至关重要。然而，BV 变化的原因仍不清楚。本研究旨在探讨影响 BV%的因素。
我们设计了一个基于系数（“a”、“τ”和“b”）的公式来预测 BV%的变化。“a”表示 HD 早期 BV%的显著下降。“τ”代表从 HD 早期到晚期的过渡。“b”表示 HD 晚期 BV%下降的斜率。我们测量了 18 名终末期肾病患者的 BV%。通过使用最小二乘优化算法拟合患者的实验数据来估计系数。对这些参数与患者透析前数据进行相关性分析。
超滤率（UFR）与“b”呈负相关（r = -0.851，p < 0.01）。然而，UFR 与“a”无显著相关性。透析前血清总蛋白水平与“a”呈负相关（r = -0.531，p = 0.042）。透析前血清白蛋白和透析前钠与“a”和“τ”无显著相关性。血浆渗透压与“a”和“τ”无显著关系。
讨论/结论：UFR 影响晚期 BV%的下降，但不影响早期 BV%的下降。“a”与透析前血清总蛋白水平相关，与血浆渗透压或透析前钠无关。这意味着胶体渗透压对透析开始后立即的血浆再填充很重要。在 BV%变化过程中，透析早期的下降与 UFR 无关，但与其他参数有关，尤其是透析前总蛋白水平。透析晚期的下降与 UFR 有关。
