Fractional electrolyte excretion and osmolality in the early diagnosis of acute kidney injury in cats with urethral obstruction

Resumo

Acute Kidney Injury (AKI) can be defined as a spectrum of diseases associated with a sudden onset of a renal failure status, the feline patient has azotemia, the disorder in fractional electrolyte excretion (FE), and shedding of epithelial cells from renal tubular segments observed in the urinary sediment. Thus, the objective of the present study was to evaluate the FE, plasma and urinary osmolality, and urinary specific gravity (USG) in cats that spontaneously developed AKI due to urethral obstruction (UO) and healthy cats. Blood and urine samples were collected from a group of 20 cats diagnosed with AKI secondary to urethral obstruction (GAKI; n=20) and clinically healthy cats (GC; n=15). The serum creatinine (sCre) and urinary creatinine (uCre), were measured by spectrophotometry, serum and urinary analyzes of sodium, potassium and chloride by ion selective electrode device and serum and urinary osmolarity by osmometer. The GAKI results were statistically compared with those of the CG using Student's t tests to assess normal data, while the Maan-Whitney test was used for non-normal data. A significant increase in the sCr, sK, FENa, FECl and RFI parameters of the GAKI cats when compared to the GC (p < 0.05). The sCl, USG, uCr, uK and uOSM parameters decreased significantly when compared between the two groups. Thus, given the established methodology and the results found, it is possible to infer that an increase in EFNa, EFCl in addition to the RFI and a decrease in USG and uOSM were associated with cats with AKI and can serve as markers of kidney damage, as well as monitoring the prognosis.