Supplementary Material for: Hepatic Oxygenation Changes and Symptomatic Intradialytic Hypotension

Introduction: Clinical studies on differences among changes in cerebral and hepatic oxygenation during hemodialysis (HD) in patients with and without intradialytic hypotension (IDH) are limited. We investigated changes in intradialytic cerebral and hepatic oxygenation before systolic blood pressure (SBP) reached the nadir during HD and compared these differences between patients with and without symptomatic IDH.
Methods: We analyzed data from 109 patients with (n=23) and without (n=86) symptomatic IDH who were treated with HD. Cerebral and hepatic regional oxygen saturation (rSO2), as a marker of tissue oxygenation and circulation, was monitored during HD using an INVOS 5100c oxygen saturation monitor. Changes in cerebral or hepatic rSO2 when SBP reached the nadir during HD were compared between the groups of patients.
Results: The cerebral rSO2 before HD in patients with and without symptomatic IDH was 49.7 ± 11.2% and 51.3 ± 9.1% (p = 0.491). %Changes in cerebral rSO2 did not significantly differ between the two groups from 60 min before the SBP nadir during HD. Hepatic rSO2 before HD in patients with and without symptomatic IDH were 58.5 ± 15.4% and 57.8 ± 15.9% (p = 0.869). The %changes in hepatic rSO2 were significantly lower in patients with symptomatic IDH than in those without throughout the observational period (p < 0.001). We calculated the area under the receiver operating characteristic curve (AUC) and estimated cut-off values for changes in hepatic rSO2 as a symptomatic IDH predictor. The predictive ability at 5 and 40 min before symptomatic IDH onset was excellent, with AUCs and cut-off values of 0.847 and 0.841, and -10.9% and -5.0%, respectively.
Conclusions: Hepatic oxygenation significantly decreased more in patients with symptomatic IDH before its onset, than in those without symptomatic IDH, whereas changes in cerebral oxygenation did not differ. Evaluating changes in hepatic oxygenation during HD might help to predict symptomatic IDH.

引言：关于血液透析（HD）过程中伴有和未伴有透析间期低血压（IDH）的患者大脑和肝氧合变化差异的临床研究有限。本研究旨在探讨血液透析过程中收缩压（SBP）达到最低点之前的大脑和肝氧合变化，并比较伴有和未伴有症状性IDH的患者之间的这些差异。
方法：我们对109例接受血液透析治疗的伴有（n=23）和未伴有（n=86）症状性IDH的患者进行了分析。使用INVOS 5100c氧饱和度监测仪在血液透析过程中监测大脑和肝区域氧饱和度（rSO2），作为组织氧合和循环的标志。比较了两组患者在血液透析过程中收缩压达到最低点时大脑或肝rSO2的变化。
结果：伴有和未伴有症状性IDH的患者在血液透析前的大脑rSO2分别为49.7 ± 11.2%和51.3 ± 9.1%（p = 0.491）。从SBP达到最低点前的60分钟开始，两组患者的 cerebral rSO2变化百分比无显著差异。伴有和未伴有症状性IDH的患者在血液透析前肝rSO2分别为58.5 ± 15.4%和57.8 ± 15.9%（p = 0.869）。在整个观察期间，症状性IDH患者的肝rSO2变化百分比显著低于未伴有症状性IDH的患者（p < 0.001）。我们计算了接收者操作特征曲线下面积（AUC）并估计了肝rSO2变化作为症状性IDH预测因子的截止值。在症状性IDH发作前5分钟和40分钟，预测能力均出色，AUC和截止值分别为0.847和0.841，以及-10.9%和-5.0%。
结论：在症状性IDH发作前，伴有症状性IDH患者的肝氧合显著降低，而大脑氧合的变化并无差异。评估血液透析过程中的肝氧合变化可能有助于预测症状性IDH。