Long-term precision of glomerular filtration rate measurements using Cr-51-EDTA plasma clearance
Long-term precision of glomerular filtration rate measurements using Cr-51-EDTA plasma clearance
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DOI：
10.1097/00006231-199708000-00012
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发表时间：
1997-08-01
影响因子：
1.5
通讯作者：
Lazarus, CR
中科院分区：
文献类型：
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作者：
Blake, GM;Roe, D;Lazarus, CR
在一项回顾性研究中评价了铬-51乙二胺四乙酸（Cr-51-EDTA）测量肾小球滤过率（GFR）的长期精密度，该研究收集了12年的数据。每个GFR测量值来自注射3 MBq Cr-51-EDTA后2、3和4 h采集的血浆样本。对7507例患者的记录进行了审查，其中55例受试者被确定为参加了10次或以上的研究。平均9.4年（范围4.3-11.8年）内，每例患者的平均研究数量为12.9（范围10-23）。绘制每例患者的GFR、清除半衰期（T-1/2）和分布容积（V-D）图，并用于确定显示随时间线性变化的受试者，这些变化可使用线性回归拟合。每个残差表示为根据回归线计算的预期值的百分比，所有残差合并以给出GFR、T-1/2和V-D的直方图。每个直方图均拟合有-3 S. D. +3 SD使用加权最小二乘限制。变异系数的最终结果为：GFR 9.8%，T-1/2 6.7%，V-D 9.4%。精密度误差用于计算Cr-51-EDTA技术可测量的最小统计学显著性变化。在10%显著性和80%把握度下，GFR的最小可测量变化为30%，T-1/2为20%。除非有临床依据认为患者的分布容积发生了变化，否则T-1/2是识别肾功能真实的变化的最佳参数。
The long-term precision of chromium-51 ethylenediamine tetraacetic acid (Cr-51-EDTA) measurements of glomerular filtration rate (GFR) was evaluated in a retrospective study of data obtained over a 12 year period. Each GFR measurement was derived from plasma samples taken at 2, 3 and 4 h following injection of 3 MBq Cr-51-EDTA. The records of 7507 patients were reviewed, from which 55 subjects were identified as having had studies on 10 or more occasions. The mean number of studies per patient was 12.9 (range 10-23) over a mean period of 9.4 years (range 4.3-11.8 years). Plots of GFR, clearance half-life, (T-1/2) and volume of distribution (V-D) were drawn for each patient and used to identify subjects showing linear changes with time that could be fitted using linear regression. Each residual was expressed as a percentage of the expected value calculated from the regression line and all the residuals combined to give histograms for GFR, T-1/2 and V-D. Each histogram was fitted with a normal distribution between the -3 S.D. and +3 S.D. limits using weighted least squares. Final results for the coefficient of variation were: GFR 9.8%, T-1/2 6.7%, V-D 9.4%. The precision errors were used to calculate the smallest statistically significant change measurable by the Cr-51-EDTA technique. With 10% significance and 80% power, the smallest measurable change was 30% for GFR and 20% for T-1/2. Unless there are clinical grounds for thinking that a patient's volume of distribution has changed, T-1/2 is the optimal parameter for identifying real changes in renal function.