Investigators from multiple institutions conducted a prospective cohort study to identify predictors of abnormal renal bladder ultrasounds (RBUS) in young children with a first febrile UTI. Study participants were patients 0 to 24 months old hospitalized with a first febrile UTI at a quaternary care children’s hospital between October 2016 and December 2018. Eligible children were identified on an ongoing basis by review of the medical records of hospitalized patients who had a urine culture performed. Children were considered to have a febrile UTI if they had a temperature ≥100.4°F, a urine specimen was obtained by suprapubic aspiration or catheterization and grew ≥50,000 colony forming units (CFU) on culture, and pyuria was present on urinalysis (positive leukocyte esterase or ≥5 white blood cells per high power field); infants <2 months old were included if their urine culture grew ≥10,000 CFU with pyuria or ≥50,000 CFU. Demographic and clinical data were collected on study participants by interview with caregivers and review of the medical record. Information collected included gestational age, family history of kidney disease, uropathogen (Escherichia coli vs others), presence of bacteremia, sex, and, in males, history of circumcision. Information regarding prenatal ultrasound (PNUS) was collected by caregiver interview and included number of PNUS, trimester of last PNUS, and results.
The primary study outcome was abnormal RBUS during the hospitalization for febrile UTI. A multidisciplinary team developed criteria for defining a clinically significant abnormal RBUS based on specific findings reported by the radiologist. Possible demographic or clinical predictors of an abnormal RBUS identified by bivariate analyses were included in a multivariate logistic regression model to identify independent predictors.
Data were analyzed on 211 children. Among these children, the median age was 1.0 month (65% were <2 months old), and 60% were male, of whom 91% were uncircumcised. Urine cultures grew E coli in 85% of study patients, and 20% had bacteremia. All study children had PNUS, 84% had ≥3, and 84% had a PNUS in the last trimester; the last PNUS in 10% of patients was reportedly abnormal. With bivariate analysis, gestational age and abnormal PNUS were identified as possible predictors of an abnormal RBUS; however, in the multivariate analysis neither of these was independently associated with an abnormal RBUS.
The authors concluded that no independent predictors of an abnormal RBUS were identified in this study.
Dr Winer has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.
Over the last 10 years there has been a shift toward reducing unnecessary imaging in infants and toddlers presenting with febrile UTIs.1 Based on evidence that medical treatment of low-grade vesicoureteral reflux does not prevent subsequent UTIs or...