Diagnostic Performance of Fractional Excretion of Urea in Evaluating Patients with Acute Kidney Injury with Diuretics Treatment

Lim, Dae Hun; Jeong, Ji Min; Oh, Seul Hyun; Lee, Hyung Chul; Choi, Joon Suk; Kim, Min Jee; Park, Jeong Woo; Bae, Eun Hui; Ma, Seong Kwon; Kim, Nam Ho; Kim, Soo Wan

Abstract

PURPOSE:Although fractional excretion of sodium (FENa) has been used to distinguish transient-acute kidney injury (T-AKI) from persistent-AKI (P-AKI), the availability of FENa in the diagnosis of T-AKI is reported low in patients with diuretics use. We compared the diagnostic performance of fractional excretion of urea (FEUrea) with that of FENa in patients with diuretics use.
METHODS
One hundred seven AKI patients were classified as having T-AKIor P-AKI according to the clinical context. Each group was again subdivided according to exposure to diuretics. According to the cut off value generated by receiver operating characteristic (ROC) curves, sensitivity and specificity of FENa and FEUrea were compared with each other.
RESULTS
The numbers of patients administered with diuretics were 67 out of total 107 AKI patients (63%), 27 out of 52 (52%) of T-AKI patients, and 40 out of total (65) 55 (73%) of P-AKI patients. When the cutoff value of T-AKI was defined as FENa < or =1.5 and FEUrea < or = 30 according to the ROC curves, sensitivity and specificity of FENa were 96% and 100% in non-diuretics group, and 63% and 98% in diuretics group, respectively. Sensitivity and specificity of FEUrea were 92% and 87% in non- diuretics group, and 96% and 83% in diuretics group, respectively.
CONCLUSION
FEUrea is as good as FENa at distinguishing T-AKI from P-AKI in patients administered with diuretics.