Role of supravital staining of urine sediment and bright field microscopy in diagnosis of acute renal failure in bedside medicine.

ABSTRACT

BACKGROUND: An early accurate etiological categorization of acute renal failure (ARF) into acute glomerulonephritis (AGN), acute tubular necrosis (ATN) and acute interstitial nephritis (AIN) is very important in clinical medicine. METHODS: To evaluate the efficacy of a simple, cheap supravital staining method developed in our laboratory, we examined urine of 32 cases of ARF at their initial presentation in oliguric phase, which were later biopsied. The stain consisted of 1% crystal violet and 0.5% safranin in normal saline. The coverslip preparations of coded and stained urine sediments were examined under ordinary bright field microscope (BFM) by two independent observers. RESULTS: The renal biopsy showed 12 cases of AGN, 12 ATN and 8 AIN. The diagnosis could be predicted by supravital staining method in 75% cases with 95% uniformity among two observers with a sensitivity of 85.7% for AGN followed by AIN (80%) and ATN (75%). CONCLUSION: Thus this simple supravital staining technique can be used with ordinary BFM for accurate urine sediment analysis in cases of ARF in bedside medicine.