生物电阻抗技术监测血液透析时细胞外液量及其临床价值

目的：采用生物电阻抗技术监测血液透析过程中患者细胞外液量（ECV）的变化，以指导调整透析患者于体质量，透预防析中低血压或难治性高血压。方法：100例维持性血透患者，透析时间4～112（58．67±31．54）个月，根据临床表现分为正常血压组、症状性低血压组和难治性高血压组。采用生物电阻抗仪测定患者血透时的细胞外液量（ECV）％、细胞内液量（ICV）％、ECV／ICV的变化。观察透析过程中患者心率、呼吸、血压、超滤量和超滤率的变化，比较3组各项指标的变化，并分析各参数同的相互关系。结果：透析过程中随超滤量增加，超滤脱水率逐渐下降，3组中症状性低血压组超滤量最大，超滤率最高；难治性高血压组超滤量最小，超滤率最低。透析前3组ECV％、ECV／ICV均高于正常对照组，其中难治性高血压组最高。透析后3组ECV％、ECV/ICV均。显著下降,但难治性高血压组仍显著高于正常对照组。透析后3组ICV％显著升高，但仍低于正常对照组。透析时症状性低血压组随ECV下降，平均动脉压（MAP）明显下降，两者呈显著正相关（r=0．914，P〈0．001）。难治性高血压组随ECV下降，MAP逐渐升高，两者呈现负相关（r=-0．782，P=0．035）。对5例低血压和7例高血压患者在生物电阻抗监测ECV的指导下分别上调或下调干体质量后血压得到有效控制。结论：生物电阻抗监测ECV有助于指导调整干体质量，确定合适的超滤量，预防透析中低血压和控制高血压。

The Effect of Extracellular Water Volume Monitor Using Bioelectric Impedance Technique on Control of Blood Pressure during Hemodialysis

Objective：To prevent hemodialysis associated complications such as symptomatic hypotension and dialysis-refractory hypertension through the adjustment of dry weight,with bioelectric impedance（BEI） technique which could monitor the changes of extracellular volume during hemodialysis. Methods：One hundred maintenance hemodialysis patients with an average dialysis course of 58.67 ± 31.54 months were enrolled. The patients were divided into 3 groups： normal blood pressure group（n = 34）, symptomatic hypotension group （n = 22）, and refractory hypertension group （n = 44）. Using the BEI technique, we measured the changes of ECV% and ICV% and ECV/ICV, and analyzed its influence on heart rate, respiration rate, blood pressure, uhrafiltration volume and uhrafihration rate. Results：The uhrafiltration rate decreased gradually with the increase of removed fluid by uhrafihration. Symptomatic hypotension group had the highest ultrafihration volume and the highest uhrafiltration rate, while the lowest ultrafihration volume and uhrafihration rate occurred in the refractory hypertension group. The pre-hemodialysis ECV% and ECV/ICV in three groups were higher than those of normal control group, the refractory hypertension group has the highest values （P〈0. 05）. The post-hemodialysis ECV% and ECV/ICV were significantly lower than their pre-hemodialysis values, but the refractory hypertension group still has a higher values compared with the normal control group （P〈0.05）. ICV% increased significantly after hemodialysis therapy, but still lower than that in normal control group. In symptomatic hypotension group, with the increase of extracellular fluid removal by hemodialysis uhrafihration, MAP de creased gradually. A significant positive correlation was observed between ECV and MAP（r = 0. 914, P〈0.001）. As for the re- fractory hypertension group, with the increase of extracellular fluid removal, MAP increased gradually. A significant negative correlation was observed between ECV and MAP（r =