生物电阻抗频谱法分析血液透析患者体液分布异常及其对血压的影响

Abnormality of fluid distribution and its effect on blood pressure in hemodialysis patients analyzed by bioelectrical impedance spectroscopy method

目的了解血液透析(HD)患者透析前后体液的分布状况及其对血压的影响。方法106例健康志愿者作为正常对照,按性别分为组用生物电阻抗频谱法检测并计算细胞外2,液(ECV)、细胞内液(ICV)占体重的百分比(ECV%、ICV%)和ECV/ICV比值。选择我院透析龄月2以上的稳定HD患者67例,按照透析前后血压状况将患者分为低血压倾向组、正常血压组、普通高血压组和顽固性高血压组,分别于透析前和透析后测量体重、ECV、ICV,并计算ECV%、ICV%和ECV/ICV比值。ECV、ICV采用电生物阻抗分析仪测定。结果HD患者ECV%、ECV/ICV透后较透前下降,而ICV%上升;透前ECV%、ECV/ICV明显高于正常对照,透后接近正常人群水平。顽固性高血压患者(均为男性)透后ECV%仍明显高于正常对照水平[(31.6±1.0)%比(25.3±1.6)%,P<0.01],而低血压倾向患者均为女性在透析前()ECV%即与正常对照水平无明显差异[(21.6±1.5)%比(22.6±1.4)%,P>0.05],透后明显低于正常对照水平[(19.3±1.6)%比(22.6±1.4)%,P<0.01]。结论HD患者水分布与正常人相比存在着明显不同,表现为ECV%增加和ICV%减少,而血液透析通过脱水和水分向细胞内转移部分纠正了这种异常。ECV%反映了HD患者水负荷的情况,并与血压之间存在着密切的关系。

Objective To investigate the abnormality of fluid distribution and its effect on blood pressure (BP) in hemodialysis patients. Methods One hundred and six healthy volunteers as normal controls were divided into two groups(male group and female group).ECV%?ICV%(% means a percentage of weight) and ECV/ICV were measured by bioelectrical impedance spectroscopy and calculated in 2 groups respectively.Sixty-seven stable HD patients who had been on HD for more than 2 months in our hospital were selected. Patients were divided into 4 groups (hypotension prone group, normotensive group, hypertensive group and refractory hypertensive group). ECV%, ICV% and ECV/ICV were measured and calculated as above immediately before and after HD session. The measurement was conducted by Xitron 4200 HYDRA ECF/ICF Bio-Impedance Spectrum Analyzer. Results In patients on HD, a significant decrease of ECV% and ECV/ICV, and a significant increase of ICV% were seen post-HD. The pre-HD ECV% and ECV/ICV were significantly higher than those of normal controls but dropped close to normal level after hemodialysis. Post-HD ECV% was still higher than that of normal controls[(31.6±1.0)% vs (25.3±1.6)%, P < 0.01]in refractory hypertension group.However,pre-HD ECV% in hypotension prone group was already similar to that of normal controls [(21.6±1.5)% vs (22.6±1.4)%, P > 0.05]and post-HD ECV% of these patients was significantly lower than that of normal controlsand post-HD ECV% of these patients was significantly lower than that of normal controls[(19.3±1.6)% vs (22.6±1.4)%,P < 0.01). Conclusions The fluid distribution of patients on HD is significantly different from normal controls. They have higher ECV% and lower ICV% value than normal controls before HD. During HD session fluid shifts from extracellular to intracellular space, which can correct partly the abnormality. ECV% can reflect fluid load status in hemodialysis patients and is closely related with blood pressure.