目的 应用人体组织生物电阻率ρ作为测定干体重的方法评价透析患者的体液平衡状态，并对其含义与影响因素进行研究。方法 应用溴化钠分别测定正常男性和女性的细胞外液容积及其相应参数，比较ρ与这些参数的相关性。分别测定血液透析前、后患者血浆中主要电解质的浓度及其血浆电阻率和人体电阻率；比较透析前、后电解质浓度的变化对血浆电阻率与人体电阻率ρ的影响，同时观察超滤量（UFV）对ρ的影响。结果 ρ与单位体积组织的细胞外液容量 (EFV/Mass) 呈显著负相关，r = -0.7841，P<0.05。透析前、后细胞外液中主要阴、阳离子浓度及血浆电阻率均无明显变化；单位体积超滤量（UFV/Mass）与ρ相关的EFV/Mass的改变呈显著正相关，r=0.6203，P<0.05。结论 人体下肢电阻率ρ随细胞外液容量变化而变化，能够准确反映单位体积人体组织的细胞外液容量，可以作为监测透析患者体液变化、设定干体重的指标。

Objective To develop a simple and reliable technique for measuring dry-weight and detecting the abnormalities of hydrational status in dialysis patients for the assesment of dry-weight is one of the important things for dialysis in clinical concern. Method Low-frequenly resistemce of lower limb (ρ) was used as a specific parameter to indicate dry-weigt. Extracellular fluid volume (EFV) and extracellular fluid volume per body mass (EFV/mas) by na truim bromine method in healthy controls were measured and the correlationship between ρ and these parementers were studied. The plasma destrolyte concentration of prehemodialysis patients, posthemodialysis patients and healthy controls were measured and the influence of these changes on the ρ were observed. Results The ρ was significantly correlated with EFV/mass measured by NaBr, r=-0.7841, P<0.05. The concentrations of main anion and cation had no change pre and post-dialysis. The ratio of ultrafiltrated volume(UFV)to the body mass (UFV / mass) was positively correlated with the alteration of EFV/mass predicated by ρ, r=0.6203, P<0.05. Conclusions The ρ means extracellular fluid volume per body mass, and it changes with the alteration of EFV/mass. It can simply and acurately indicate the hydrational status of dialysis patients.