Urine Microscopy Findings Predict Outcomes In Hospitalized Patients With Acute Kidney Injury

Though urine microscopy has long been highly regarded by nephrologists as an essential diagnostic tool, its potential utility in predicting outcome in acute kidney injury (AKI) warrants further exploration. In this study, urine sediment microscopy was performed on 165 hospitalized patients on the first day of their clinical AKI diagnosis to determine whether microscopy findings early in the course of this disease correlate with worsening, a composite of increasing AKI stage and in-hospital mortality. Microscopy findings were recorded as individual cells and casts along with a microscopy score derived from renal tubular epithelial (RTE) cells and granular casts. Our data suggest that both increasing numbers of granular casts and a higher microscopy score are predictive of overall worsening (p = 0.027 and p = 0.046, respectively), but other microscopy features such as the number of RTE cells are not. These data demonstrate that urine microscopy even at the time of initial diagnosis can be predictive of eventual outcome, potentially serving as a useful adjunct to clinical and other biochemical data in the study of AKI