Retooling the Creatinine Clearance Equation to Estimate Kinetic GFR when the Plasma Creatinine Is Changing Acutely
Retooling the Creatinine Clearance Equation to Estimate Kinetic GFR when the Plasma Creatinine Is Changing Acutely
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DOI：
10.1681/asn.2012070653
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发表时间：
2013-06-01
影响因子：
13.6
通讯作者：
Chen, Sheldon
中科院分区：
文献类型：
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作者：
Chen, Sheldon
通常需要在床边估计 GFR (eGFR) 以评估 AKI 或肾脏恢复情况。目前的 eGFR 方程可在血浆肌酐稳定时估计肾功能，但如果血浆肌酐快速变化则不起作用。为了分析急性环境下的肾功能，提出了一个简单的公式，该公式仅需要少量的输入，这些输入可以很容易地从临床实验室数据中获得。所谓的动态 eGFR (KeGFR) 公式源自初始肌酐含量、分布容积、肌酐生成率以及给定时间内连续血浆肌酐之间的定量差异。在此期间，破译肌酐排泄量即可得出肌酐清除率。所需的附加公式变量包括任何稳态血浆肌酐、经验公式对应的 eGFR，以及无尿时每天肌酐的最大增量。该动力学公式补充了临床直觉，还为肾功能评估增加了定量和视觉维度，这通过对几种 AKI 或肾脏恢复情况下血浆肌酐波动背后的 GFR 的分析得到证明。 KeGFR 公式从肌酐平衡生理学的基本原理推导出来，增强了基本的清除方程，具有在血浆肌酐急剧变化时估计肾功能的能力和多功能性。
It is often desirable to estimate the GFR (eGFR) at the bedside to assess AKI or renal recovery. Current eGFR equations estimate kidney function when the plasma creatinine is stable, but do not work if the plasma creatinine is changing rapidly. To analyze kidney function in the acute setting, a simple formula is proposed that requires only a modest number of inputs that are readily obtainable from clinical laboratory data. The so-called kinetic eGFR (KeGFR) formula is derived from the initial creatinine content, volume of distribution, creatinine production rate, and the quantitative difference between consecutive plasma creatinines over a given time. For that period, the deciphered creatinine excretion then yields the creatinine clearance rate. The additional formula variables needed are any steady-state plasma creatinine, the corresponding eGFR by an empirical formula, and the maximum increase in creatinine per day if anuric. The kinetic formula complements clinical intuition but also adds a quantitative and visual dimension to the assessment of kidney function, demonstrated by its analysis of GFRs underlying the plasma creatinine fluctuations in several scenarios of AKI or renal recovery. Deduced from first principles regarding the physiology of creatinine balance, the KeGFR formula enhances the fundamental clearance equation with the power and versatility to estimate the kidney function when the plasma creatinine is varying acutely.