Patients with kidney failure treated with hemodialysis (HD) may be at risk for cerebral hypoperfusion due to HD-induced BP decline in the setting of impaired cerebral autoregulation. Cerebrovascular reactivity (CVR), the cerebrovascular response to vasoactive stimuli, may be a useful indicator of cerebral autoregulation in the HD population and identify those at risk for cerebral hypoperfusion. We hypothesize that CVR combined with intradialytic BP changes will be associated with declines in cerebral oxygenation saturation (ScO₂) during HD.

Participants completed the MRI scans on a non-HD day and cerebral oximetry during HD. We measured CVR with resting-state fMRI (rs-fMRI) without a gas challenge and ScO₂ saturation with near-infrared spectroscopy. Regression analysis was used to examine the relationship between intradialytic cerebral oxygen desaturation, intradialytic BP, and CVR in different gray matter regions.

Twenty-six patients on HD had complete data for analysis. Sixteen patients were men, 18 had diabetes, and 20 had hypertension. Mean±SD age was 65.3±7.2 years, and mean±SD duration on HD was 11.5±9.4 months. CVR in the anterior cingulate gyrus (ACG; P=0.03, r²=0.19) and insular cortex (IC; P=0.03, r²=0.19) regions negatively correlated with decline in intradialytic ScO₂. Model prediction of intradialytic ScO₂ improved when including intradialytic BP change and ultrafiltration rate to the ACG rsCVR (P<0.01, r²=0.48) and IC rsCVR (P=0.02, r²=0.35) models, respectively.

We found significant relationships between regional rsCVR measured in the brain and decline in intradialytic ScO₂. Our results warrant further exploration of using CVR in determining a patient’s risk of cerebral ischemic injury during HD.

接受血液透析（HD）治疗的肾衰竭患者可能面临脑灌注不足的风险，因为在脑自动调节受损的情况下，HD 会导致血压下降。脑血管反应性（CVR），即脑血管对血管活性刺激的反应，可能是 HD 人群脑自动调节的有用指标，并识别那些有脑灌注不足风险的人。我们假设 CVR 与透析期间血压变化相结合与HD 期间脑氧饱和度 (ScO ₂ )的下降有关。

参与者在非 HD 日完成 MRI 扫描，并在 HD 期间完成脑血氧测定。我们在没有气体挑战的情况下使用静息态 fMRI (rs-fMRI) 测量了 CVR，并使用近红外光谱测量了ScO _{2饱和度。}采用回归分析来检验不同灰质区域透析中脑氧饱和度、透析中血压和CVR之间的关系。

26 名 HD 患者拥有完整的数据可供分析。16 名患者为男性，18 名患有糖尿病，20 名患有高血压。平均±SD年龄为65.3±7.2岁，平均±SD HD持续时间为11.5±9.4个月。前扣带回（ACG；P =0.03，r ² =0.19）和岛叶皮质（IC；P =0.03，r ² _{=0.19）区域的 CVR 与透析中 ScO 2}下降呈负相关。当分别将透析中血压变化和超滤率纳入ACG rsCVR（P <0.01，r ² =0.48）和IC rsCVR（P =0.02，r ² _{=0.35）模型时，透析中ScO 2}的模型预测得到改善。

我们发现大脑中测量的区域 rsCVR 与透析中 ScO ₂下降之间存在显着关系。我们的结果值得进一步探索使用 CVR 来确定患者 HD 期间发生脑缺血损伤的风险。