人体成份分析仪联合在线清除率监测评估血液透析剂量的临床应用价值

Evaluation of hemodialysis adequacy using body composition monitor combined with online clearance monitoring

目的通过单中心前瞻性自身对照研究探讨人体成份分析仪(body composition monitor,BCM)联合在线清除率监测(online clearance monitoring,OCM)评估血液透析充分性的准确性和实用性。方法选取维持性血液透析(maintance hemodialysis,MHD)患者138例,在同一次血液透析中应用3种评估透析充分性方法:(1)血液透析前后抽取患者全血检测尿素氮水平,根据Daugirdas公式计算Kt/V_(Dau);(2)应用OCM计算Kt/V_(Ocm)(尿素分布容积V值由Watson公式计算得出);(3)应用BCM计算Kt/V_(Bcm)(尿素分布容积V值由BCM测量得出,Kt值由OCM计算得出)。另外,以Kt/V_(Bcm)-Kt/V_(Ocm)差值0.25(根据Bland-Altman分析平均差值得出)为界,分为Kt/V_(Bcm)-Kt/V_(Ocm)<0.25组和Kt/V_(Bcm)-Kt/V_(Ocm)≥0.25组,比较2组患者临床资料和身体成份各项指标差异。结果本研究共纳入138例MHD患者,男性76例,占55.934%,平均年龄(54.934±12.705)岁。3种方法评估透析剂量分别为Kt/V_(Dau)1.432(1.235,1.718),Kt/V_(Bcm)1.434(1.244,1.642),Kt/V_(Ocm)1.177(1.076,1.355),Kt/V_(Dau)与Kt/V_(Bcm)比较无统计学意义(Z=-0.224,P=0.823)。箱图显示Kt/V_(Dau)存在较多"温和异常值"和"极端异常值"。Bland-Altman分析显示Kt/V_(Dau)与Kt/V_(Bcm)平均差值为0.07,95%置信区间(0.020,0.204),相关系数为0.842(0.821~0.862)。Kt/V_(Ocm)和Kt/V_(Bcm)值的差异与两种方法使用不同尿素分布容积V值有关(t=25.400,P<0.001)。高龄(t=-3.748,P<0.001)、女性(c2=5.163,P=0.023)、低肌肉组织指数(t=11.345,P<0.001)、低人体总液量(t=7.988,P<0.001)、低细胞内外液量(t=5.878,P<0.001;t=8.564,P<0.001)和高脂肪组织指数(t=-4.242,P<0.001)患者Kt/V_(Bcm)-Kt/V_(Ocm)差值越大。LTI和LTI_(dtr)与Kt/V_(Bcm)-Kt/V_(Ocm)差值相关性最强(g=-0.781,P<0.001;g=-0.728,P<0.001)。结论 BCM联合OCM监测功能可稳定、全面、准确评估患者透析剂量和有利于优化透析处方,值得临床推广使用。

Objective To evaluate the adequacy of hemodialysis by Body Composition Monitor（BCM） and Online Clearance Monitoring（OCM）. Methods In a prospective clinical trial,including 138 patients,three different methods determining dialysis dose were simultaneously applied：Kt/VDau（conventional method with Daugirdas formula）,Kt/VOcm（online clearance measurement with urea distribution volume V based on anthropometric estimate）,and Kt/VBcm （OCM measurement with V measured by BCM）.Using the difference value of 0.25（between Kt/VBcm and Kt/VOcm） as the boundary,we divided the patients into two groups：Kt/VBcm-Kt/VOcm〈0.25 group and Kt/VBcm-Kt/VOcm〉0.25group.Clinical indices were compared between the two groups. Linear regressiong was applied to analyze the potential impact factors of the difference between Kt/V values calcualted by the two methods. Results A total of 138 MHD patients with an average age of （54.934±12.705）years old were enrolled, and 55.934% of them were males.The dialysis dose was measured as Kt/VDau=1.583±0.649,Kt/VBcm=1.471±0.300, and Kt/VOcm=1.220±0.204. Kt/VDau was incidentally prone to falsely high values due to operative errors,whereas in these cases OCM-based measurement Kt/VBcm and Kt/VOcm delivered realistic values. An excellent correlation was observed between Kt/VDau and Kt/VBcm,the mean difference was 0.07, 95%CI（0.79,-0.66）,the correlation coefficient was 0.842（0.821~0.862）.The difference between Kt/VBcm and Kt/VOcm was due to the difference between anthropometric estimated Vwatson and measured VBCM.A higher mean Kt/VBcm - Kt/VOcm value was correlated to older age（p=0.000）, femal（（p=0.023）, higher fat tissue index（p=0.000）, lower total body water（p=0.000）, lower extracecellar water（p=0.000）, lower innercellar water（p=0.000）, and lower lean tissue index（p=0.000）. Conclusion BCM can give more accurate parameters of urea distribution volume , thus modifying the result of Kt/V.It is very useful not only in monitoring the adequacy of dialysis ,but also in evaluating nutritional status.