BIA法评估维持性血液透析患者水平衡及干体质量

Evaluation of fluid balance and dry weight with BIA in patients with maintenance hemodialysis

目的采用全身生物电阻抗分析(BIA)法评估维持性血液透析(MHD)患者水平衡动态变化及干体质量。方法选择血液透析龄≥1年且病情稳定的20例MHD患者作为研究对象(MHD组),分别于血液透析前后及透析间期(透析后24 h和48 h)采用BIA法测定细胞外液量(ECW)和细胞内液量(ICW),计算并获得相关指标;分析MHD患者0 h达到干体质量与否及其平均每日尿量对ECW和ICW的影响。以20名健康志愿者作为正常对照组。结果与正常对照组比较,MHD组透析前理想体质量纠正的ECW明显升高(P<0.05)。在MHD组中,血液透析后ECW较透析前明显下降(P<0.05);与透析前和透析间期比较,血液透析后ECW/机体总水量(TBW)降低,ICW/TBW升高,差异均有统计学意义(P<0.05);各时间点ICW和ECW与患者相应体质量显著相关;达到干体质量患者0 h和24 h时间点理想体质量纠正的ICW和ECW均明显高于未达到干体质量患者(P<0.05);尿量<400 mL/d的患者透析前和透析后24 h,ECW和ICW均显著低于尿量≥400 mL/d的患者(P<0.05)。结论BIA法研究提示,MHD患者血液透析前后及透析间期水平衡动态变化以ECW为主,评价指标以ECW/TBW较为敏感;理想体质量纠正的ICW和ECW可能是评判干体质量的敏感指标。

Objective To evaluate the fluid balance and dry weight with whole body bioelectrical impedance analysis （BIA） in patients with maintenance hemodialysis （ MHD）. Methods Twenty patients in stable condition with MHD for more than one year were selected （MHD group）. Extra-cellular water （ECW） and intra-cellular water （ICW） were measured by BIA before hemodialysis, after hemodialysis and at intervals of hemodialysis （24 h and 48 h after hemodialysis）, and related parameters were calculated. Whether patients with MHD achieved dry weight at 0 h was analysed, and the effects of average daily urine volume on ECW and ICW were explored. Another 20 healthy volunteers were served as controls. Results Compared with control group, ECW retrieved by ideal body weight was significantly higher before hemodialysis in MHD group （P 〈0.05）. In MHD group, ECW was significantly lower after hemodialysis than that before hemodialysis （P 〈 0.05）. ECW/total body water （TBW） was significantly lower and ICW/TBW was significantly higher after hemodialysis than those before hemodialysis and at intervals of hemodialysis （P 〈 0. 05）. ICW and ECW at each time point were significantly related to body weight. ICW and ECW retrieved by ideal body weight at 0 h and 24 h of those who achieved dry weight were significantly higher than those who did not achieve dry weight （P 〈 0.05）. ECW and ICW before hemodialysis and 24 h after hemodialysis were significantly lower in those with urine volume 〈400 mL/d than those with urine volume ≥400 mL/d （P 〈0.05）. Conclusion BIA analysis indicates that changes of fluid balance before hemodialysis, after hemodialysis and at intervals of hemodialysis in patients with MHD are characterized by ECW, and ECW/TBW is a more sensitive parameter. ICW and ECW retrieved by ideal body weight may be sensitive parameters to determine the dry weight in patients with MHD.