Cytodiagnostic Urinalysis Is Very Useful in the Differential Diagnosis of Acute Renal Failure and Can Predict the Severity

Abstract

Cytodiagnostic urinalysis was tested to determine its utility in the differential diagnosis of acute renal failure (ARF). Fifty-one patients with acute renal failure were included and evaluated clinically with regard to the etiology of the renal failure, whether underlying chronic renal failure was present, and if dialysis was required. Urine specimens were macroscopically examined and subjected to a multiparameter reagent-strip analysis. Papanicolaou stain was done on cytocentrifuge preparations and the number of blood cells, renal cells, and casts examined in a standardized fashion. The results showed that the 34 patients with acute tubular necrosis (ATN) of either ischemic or toxic origin had a higher number of collecting duct cells, and a higher total number of casts than the 17 non-ATN patients. Twelve patients requiring dialysis had a higher number of different types of casts (granular, waxy, leukocytic, broad casts) as well as more renal cells (mainly necrotic) than the 39 patients who did not require dialysis. A significant positive correlation was found between the magnitude of rise of serum creatinine and a number of cytodiagnostic parameters. We conclude that cytodiagnostic urinalysis may be valuable in addition to other tests in the evaluation of patients with acute renal failure.

Diagnostic Value of Urine Microscopy for Differential Diagnosis of Acute Kidney Injury in Hospitalized Patients

“…Previous studies showed that the identification of granular casts and RTEC in the urine sediment analysis correlates well with ATN (17,18). Schentag et al (17) demonstrated that the increase in urinary cast excretion provides information about kidney injury that allows one to adjust aminoglycoside dosages 5 to 9 d before a rise in serum creatinine concentration develops in patients with aminoglycoside nephrotoxicity.…”

Prognostic Value of Tubular Proteinuria and Enzymuria in Nonoliguric Acute Tubular Necrosis

“…We applied this series of criteria recently validated or established to indicate ATN because no single standard test exists to diagnose ATN (Fig. 1, step 3): (a) sepsis or systemic inflammatory response syndrome (32 ); (b) arterial hypotension (32 ); (c) intravenous administration of aminoglycosides, amphotericin B, or contrast media; (d) rhabdomyolysis, defined as serum myoglobin Ͼ10 mg/L; (e) fractionated sodium excretion Ͼ1% (29 -31 ); (f) fractionated urea nitrogen excretion Ͼ35% (31 ); (g) blood urea nitrogen-to-serum creatinine ratio Ͻ15 (6,31 ); (h) urine osmolality Ͻ300 mosmol/kg of H 2 O (6 ); and (i) tubule cells or granular casts in the urine sediment (33,34 ).…”

“…In addition, differentiation between prerenal ARF and ATN may be difficult. Although the ATN criteria applied were validated recently or are commonly acknowledged, they may not completely differentiate both conditions (6,30,31,33 ).…”

Traditional Urinary Biomarkers in the Assessment of Hospital-Acquired AKI

“…In AKI, worsening of kidney function, requirement for dialysis, and death are such end points. Marcussen and colleagues undertook such a study in 51 patients with hospital-acquired AKI who had prerenal AKI, "non-ATN" AKI, or ATN (15). They found that the number of urinary cells and granular casts had a positive correlation with the magnitude of increase in serum creatinine (i.e., worsening AKI).…”