超声稀释法监测血液透析患者的内瘘功能

目的对维持性血液透析患者进行内瘘血流量（Qb）及再循环率（R％）测定，了解血液透析患者的内瘘功能状态。方法在患者血液透析开始后30min及结束前1h采用超声稀释法测定内瘘功能。对内瘘血流量过低（Qb〈600ml／min）及过高（Qb〉1800ml／min）的患者进行彩色多普勒超声检查。测量内瘘头静脉内径、桡动脉内径、肱动脉内径及平均血流速度并排除血管腔有无狭窄。结果180例患者中的163例成功进行了内瘘功能测定，3例再循环率〉0，占0．02％。平均Qb（1010．3±662．6）ml／min，40例Qb〈600ml／min（24．5％，低流量组），104例Qb为600-1800ml／min（63.8％，正常流量组），19例Qb〉1800ml／min（11．7％，高流量组）。多普勒超声检查低流量组10例，高流量组7例。两组比较在头静脉内径、桡动脉内径、流速、肱动脉流速方面差异均有统计学意义。结论超声稀释法评定血管内瘘功能有较好的敏感性和特异性，是血管通路（包括自身血管和人造血管）功能监测的一种良好的手段。

Monitoring the function of vascular access in hemodialysis patients by ultrasound dilution method

To evaluate the function of vascular access by measuring blood flow (Qb) and recirculation in hemodialysis patients. Methods Qb and recirculation were measured by Transonic HD02 Monitor 30 minutes after the initiation and 60 minutes before the end of hemodialysis session. When the Qb was too low（Qb<600 ml/min）or too high (Qb>1800 ml/min), the internal diameter and blood flow velocity of vascular access, such as cephalic vein, radial artery and brachial artery, were measured by color Doppler ultrasonography. Results Monitoring of vascular access was successfully performed in 163 of 180 patients. Access recirculation >0 was found in 3 patients (0.02%). The mean Qb was (1010.3±662.6) ml/min. Qb<600 ml/min was found in 40 patients (24.5%), Qb=600~1800 ml/min in 104 patients (63.8%), Qb>1800 ml/min in 19 patients (11.7%). Ten patients presented low Qb measured by color Doppler ultrasonography. Among these 10 patients, stenosis at the inosculated part of blood vessel was found in 4 patients (40%), intima hyperplasia at the site frequently punctured was found in 2 patients (20%), vein shunt was found in 2 patients (20%), and the vascular access was normal in 2 patients (20%). Overall, 80% patients showed abnormalities to a certain extent. The radial arteries in all of the 7 patients whose Qb was too high were dilated. There were significant differences of the diameter of cephalic vein, radial artery and the flow velocity of radial artery, brachial artery between two groups. Conclusions Sensitivity and specificity of ultrasound dilution method in monitoring the vascular access of hemodialysis patients are quite satisfactory. This may be a simple and reliable method for access function surveillance.