Fushimi K, Shichiri M, Marumo F
Second Department of Internal Medicine, Tokyo Medical and Dental University, Japan.
Am J Nephrol. 1990;10(6):489-94. doi: 10.1159/000168174.
Although the fractional excretion of uric acid (FEUA) is known to reflect extracellular fluid volume changes, the diagnostic significance of decreased FEUA in dehydration has not been previously reported. We studied the possible association between low FEUA and acute prerenal azotemia, and its diagnostic value, compared with other traditional indices, in discriminating prerenal azotemia from renal parenchymal causes of acute renal failure. In 65 chronic renal disease patients, 174 FEUA measurements were obtained from 24-hour urine collections. FEUA levels increased as reciprocal serum creatinine levels decreased. All 8 patients with prerenal azotemia showed significantly decreased FEUA values compared with chronic renal disease patients with a comparable degree of serum creatinine elevation, whereas all 7 patients with acute renal failure had FEUA values higher than those of chronic renal disease patients with comparable creatinine levels. FEUA values in prerenal azotemia were distinctly lower than those in acute renal failure (p less than 0.001). Patients with prerenal azotemia showed a lower fractional excretion of sodium, a lower fractional excretion of chloride and renal failure index, and a higher urine-to-plasma creatinine ratio than those with acute renal failure (p less than 0.05). However, these traditional indices were not useful in discriminating between the two conditions. The urine-to-plasma urea nitrogen ratio and the ratio of plasma urea nitrogen to creatinine showed no statistical difference between prerenal azotemia and acute renal failure. We conclude that, in acute azotemia, a decreased FEUA value may represent a reliable indicator of prerenal azotemia in the differential diagnosis of acute renal failure.
虽然已知尿酸排泄分数（FEUA）可反映细胞外液量变化，但此前尚未报道FEUA降低在脱水诊断中的意义。我们研究了低FEUA与急性肾前性氮质血症之间的可能关联，以及与其他传统指标相比，其在区分肾前性氮质血症与急性肾衰竭的肾实质病因方面的诊断价值。在65例慢性肾病患者中，通过收集24小时尿液获得了174次FEUA测量值。FEUA水平随血清肌酐水平的倒数降低而升高。与血清肌酐升高程度相当的慢性肾病患者相比，所有8例肾前性氮质血症患者的FEUA值均显著降低，而所有7例急性肾衰竭患者的FEUA值均高于肌酐水平相当的慢性肾病患者。肾前性氮质血症患者的FEUA值明显低于急性肾衰竭患者（p<0.001）。与急性肾衰竭患者相比，肾前性氮质血症患者的尿钠排泄分数、尿氯排泄分数和肾衰竭指数更低，尿肌酐与血肌酐比值更高（p<0.05）。然而，这些传统指标在区分这两种情况时并无用处。肾前性氮质血症与急性肾衰竭患者的尿尿素氮与血尿素氮比值以及血尿素氮与肌酐比值无统计学差异。我们得出结论，在急性氮质血症中，FEUA值降低可能是急性肾衰竭鉴别诊断中肾前性氮质血症的可靠指标。
