Acute kidney injury in patients hospitalized with febrile urinary tract infections: A prospective observational study

Febrile urinary tract infection (fUTI) can be associated with acute kidney injury (AKI). We aimed to study the risk factors for AKI, its pathophysiological categories, and the role of urinary neutrophil gelatinase-associated lipocalin (uNGAL) in differentiating these categories in patients hospitalized with fUTI. We prospectively studied patients with fUTI admitted to the Department of Medicine of a tertiary care hospital in southern India from January 2017 to December 2018. Clinical evaluation, renal imaging, and estimation of fractional excretion of sodium (FeNa) and uNGAL were done at baseline. AKI was defined as ≥ 0.3 mg/dL rise in serum creatinine (SCr) within 48 hours during hospital stay (KDIGO criterion) or discharge SCr value 0.5 mg/dL or less compared to peak SCr after admission. We studied 100 patients. Their mean age was 52 (± 14) years; 45 were men. In all, 52 had AKI: pre-renal in 11 (21%), intrinsic renal in 24 (47%), post-renal in 16 (31%), and missing data 1 patient. uNGAL levels were significantly higher in the AKI group compared to the no-AKI group (median [IQR] 91.1 [13.2 - 188] vs. 264.9 [115.2 - 355.2] ng/mL; p