Indication for voiding cystourethrography during first urinary tract infection

There is confusion surrounding the precise indications for voiding cystourethrography (VCUG) during the assessment of vesicoureteral reflex (VUR) after a first febrile urinary tract infection (UTI). The aim of this study was to determine the combination of clinical, laboratory and ultrasonography factors correlating with grades IV-V VUR in young children with a first febrile UTI.

Children 0-24 months of age who were brought to the emergency department at National Center for Child Health and Development with the diagnosis of first time febrile UTI between March 2004 and May 2011, were enrolled. We compared clinical, laboratory and ultrasonography findings between children with grades IV-V VUR (high-grade VUR) and those with no or grades I-III VUR (normal or low-grade VUR).

A total of 231 patients were eligible and 19 had high-grade VUR. Poor clinical appearance, presence of a uropathogen other than Escherichia coli, positive blood culture, hydroureter and thickened renal pelvic wall were all independently associated with high-grade VUR. When one or more of these factors were present, sensitivity, specificity, positive or negative predictive value, and positive or negative likelihood ratio were 94.7%, 69.4%, 23.1%, 99.3%, 3.1 and 0.1, respectively. When none of the factors was present, the proportion of high-grade VUR was 0.7%; if one factor, 11.3%; two factors, 55.6%; three factors, 85.7%.

In the absence of five specific factors during the first febrile UTI episode in young children, VCUG is not necessary to detect high-grade VUR. When more than one factor is present, however, VCUG is indicated.