Reliability of FEUA in AKI and its Combination with Other Renal Failure Indices, ADEL TAIE, MOHAMAD HOSNY, ENAS ABDELLATEEF and NAEL SAMIR
Abstract
Purpose: An early detection of adult patients with acute kidney injury may provide the opportunity to treat and prevent the extension of kidney injury. Fractional excretion of sodium (FENa) has been used in the differentiation of acute kidney injury (AKI) into traditional categories of prerenal azotemia (PR) and acute tubular necrosis (ATN). However, many patients with PR have already received diuretics or saline at the time of diagnosis, which increase FENa. In contrast, the fractional excretion of uric acid (FEUA) and urea (FEUN) is less influ-enced by diuretics. We investigated the diagnostic significance of the FEUA and FEUN in differentiating between PR and ATN.
Methods: The FENa, FEUA, and FEUN were calculated in 20 patients with PR and 20 patients with ATN at day 0 (D0), day 1 (D1) and day 2 (D2), sequentially.
Results: FEUA (PR14.49±6.23% vs. ATN 47.09±23.35, p<0.001) and FEUN (PR 32.21±9.54% vs. ATN 54.97±17.14%, p<0.001) were lower in PR than in ATN patients. At the cut-off value of 1.04% FENa, sensitivity and specificity for the detection of PR was 75% and 85%, respectively. At the cut-off value of 39.4% FEUN, sensitivity and specificity for the detection of PR was 75% and 80%, respectively. At the cut-off value of 19.83% FEUA, sensitivity and specificity for the detection of PR was 85% and 90%, respectively. When FENa, FEUA and FEUN were combined, sensitivity and specificity was 84% and100%, respectively.
Conclusion: FEUA and FEUN may be useful in differen-tiating between PR and ATN. The combination of FENa, FEUA and FEUN might increase diagnostic sensitivity and specificity in the differential diagnosis of AKI.