生物电阻抗分析法评估血液透析患者干体重

目的利用生物电阻抗频谱分析法（bioimpedence analysis，BIA）了解维持性血液透析（hemodialysis，HD）患者的体液分布，同时了解其对血压的影响。方法选择苏州大学附属第一医院血透中心维持性血液透析患者85例，透析时间均大于3个月，应用BIA分别测定透析前后细胞内液（intra—cellular water，ICW）、细胞外液（extra—cellular water，ECW），并分别计算占体重的百分比（ECW％、ICW％）。另外选取83名性别、年龄、体重匹配的正常个体作为对照组。结果HD患者透前ECW％明显高于同性别正常对照（P〈0．01），透后较透前明显降低（P〈0．05），透后接近正常人群水平（P〉0．05）。HD患者ICW％透析后降低，但与透前相比无明显差异，且与同性别正常对照组亦无明显差异（P〉0．05）；HD患者高血压组透前、透后均高于正常对照（P〈0．05）；HD患者正常血压组透前高于正常对照（P〈0．05）。透后与正常对照组无显著差异；HD患者低血压组透前与正常对照无差异（P〉0．05），透后低于正常对照组（P〈0．05）。结论透析患者的体液分布存在明显异常，主要表现为透析前ECW％增加。透析脱水主要来自ECW，对ICW无明显影响。利用多频生物电阻抗测定透析后ECW％可用于评价HD患者干体重，但仍需进一步研究。

Assessment of Dry Weight in Patients on Maintenance Hemodialysis by Bio-impedance Spectrum Analysis

Objective To evaluate the fluid distribution in patients on maintenance hemodialysis by the whole-body bioimpedance spectroscopy and investigate its effect on blood pressure in hemodialysis patients. Methods A total of 85 patients with stable hemodialysis for more than 3 months were enrolled in this study.Pre- and post-dialysis intracellular water（ICW） and extracellular water（ECW） were measured by whole-body multi- frequency bio-impedance spectroscopy, and standardized by body weight to produce ICW% and ECW%.83 normal individuals of matched sex,age and body weight were used as controls.Results The pre-HD ECW% was significantly higher than those of normal controls（P 〈 0.01）,but decreased significantly after hemodialysis（P 〈 0.05）,post-HD ECW% was close to normal level after hemodialysis（P 〉 0.05）.By contrast,pre- and post-dialysis ICW% values in HD patients were similar to those of controls.Patients with hypertension had higher pre- and post-dialysis ECW% values than those without hypertension.In patients with normal blood pressure,pre- dialysis ECW% values were higher than those of controls,post-dialysis ECW% was similar to that of controls.Patients with hypotension had lower pre- and post-dialysis ECW% values than those without Hypotension.Conclusion Hemodialysis patients have higher pre-dialysis ECW%.Fluid ultrafiltration is mainly derived from extracellular water during hemodialysis.Post-dialysis ECW% may be a useful parameter for the evaluation of dry weight in HD patients.