ESTIMATION OF ARCUATE ARTERY RESISTIVE INDEX AS A DIAGNOSTIC-TOOL FORAMINOGLYCOSIDE INDUCED ACUTE-RENAL-FAILURE IN DOGS

Objective-To determine the potential clinical usefulness of duplex Dop pler estimation of arcuate artery resistive index (a measure of intrar enal blood flow impedance) for diagnosis of aminoglycoside-induced nep hrotoxicosis. Animals-30 adult, female, mixed-breed dogs, allotted to 3 groups of 10 dogs each as: toxic dosage of gentamicin, therapeutic d osage of gentamicin, and saline solution sham equivalent in volume to that of the toxic dosage of gentamicin. Procedure-After baseline scree ning to establish normalcy (serum biochemical analysis, endogenous cre atinine clearance determination, urinalysis, urine protein-to-creatine ratio, urine culture, gray-scale sonography, and percutaneous ultraso und-guided renal biopsy), results of arcuate artery resistive index de termination were compared with serum creatinine and urine specific gra vity values on a Monday-Wednesday-Friday data collection schedule for 10 days. Endogenous creatinine clearance determination, ultrasound-gui ded renal biopsy, and urine culture were repeated at the end of data c ollection in all 3 groups. Results-Significant differences in resistiv e index measurements were not observed, despite clinicopathologic and renal biopsy results compatible with severe acute tubular necrosis in dogs of the toxic dosage group. Conclusions-Duplex Doppler sonography of arcuate artery blood flow impedance, expressed as the resistive ind ex, appears to have poor clinical usefulness as a diagnostic tool in t his disorder. Clinical Relevance-Normal arcuate artery resistive index values obtained in dogs for which aminoglycoside-induced nephrotoxico sis is suspected do not exclude the disorder. If abnormal arcuate arte ry resistive index values are obtained for such dogs, further evaluati on for nephropathies other than aminoglycoside-induced nephrotoxicosis may be considered.