对吗？谢谢

Multiplying urine solute concentrations by the estimated or known urine output converts these concentrations to daily or hourly excretion rates of these substances. The familiar urine protein/creatinine ratio is based on this simple concept and the urine potassium/creatinine ratio has been suggested to substitute for the more complex (and probably invalid) transtubular potassium gradient in the evaluation of hypokalemia and hyperkalemia [8]. A calculation based on the urine creatinine concentration alone will overestimate urine output in small, elderly or frail patients with reduced muscle mass who excrete <1 g of creatinine daily and it will underestimate output in young muscular patients who excrete >1 g of creatinine daily. As was recently suggested by Decaux and Musch, a more accurate estimate of V can be obtained if the estimated glomerular filtration rate (eGFR), derived from the plasma creatinine concentration (Pcreat) using Modification of Diet in Renal Disease or Chronic Kidney Disease Epidemiology Collaboration equations, is included (Table 1) [9]. Assuming that eGFR equals creatinine clearance (which is only approximately true):

用尿液溶质浓度乘以估计的或已知的尿量可将这些浓度转化为这些物质的每日或每小时排泄率。我们熟悉的尿蛋白/肌酐比率就是基于这个简单的概念，而尿钾/肌酐比率已经被建议用来替代更复杂的（也可能是无效的）肾小管内外钾梯度来评估低钾和高钾血症。单纯以尿液肌酐浓度计算，会高估小、老年或肌体衰弱、每天排泄肌酐<1 g的患者的排尿量，也会低估每天排泄肌酐>1 g年轻肌肉多的患者的排尿量。正如Decaux和Musch最近提出的，如果将肾小球滤过率（eGFR）（通过肾脏疾病或慢性肾脏疾病流行病学合作方程中饮食的改变而得到的血浆肌酐浓度（Pcreat））考虑在内，则可以获得更准确的尿量（V）（表1）。假设eGFR等于肌酐清除率（这只是大致正确的）:

理解的对吗？尤其是这几个地方，谢谢