- Age <12 months?
- Maximum temperature ≥39°C (102.2°F)?
- Self-described race as black (fully or partially)?
- Female or uncircumcised male?
- Other fever source identified?
If the calculator generates a score corresponding to a <2 percent risk for UTI, it indicates that no urine testing is required. When the generated score indicates higher risks, providers then must move to a second step, which assesses the subsequent urinalysis results. Based on the combination of the presence or absence of nitrites, leukocyte esterase, bacteria on Gram’s stain, and the white blood cell/mm3 concentration, the calculator generates a probability of UTI. When the calculated probability is <5 percent, no empiric antibiotics are required.
Explore This IssueACEP Now: Vol 38 – No 07 – July 2019
Sometimes, the decision hinges on the eventual culture results. Whether delayed treatment causes renal impairment and hypertension later in life is controversial. American Academy of Pediatrics (AAP) guidelines suggest that delays in appropriate treatment could increase the risk of renal damage.3 Some studies suggest that early antibiotic therapy within 72 hours is necessary to prevent renal scarring. However, these studies didn’t assess patient-oriented outcomes or long-term complications like chronic renal failure and hypertension. We simply do not know whether treating pediatric UTI prevents clinically relevant renal disease.
In higher-risk patients (>2 percent risk on step 1 of the UTI calculator) or in those who appear toxically ill, it may be appropriate to treat with antibiotics empirically. Always discuss the need to have the culture results reviewed to make the definitive diagnoses (and either continue therapy or stop it based on the culture results) with the family. If the patient is at lower risk (either <2 percent via step 1 of the calculator or <5 percent via step 2) and appears well, a watchful waiting approach whereby empiric antibiotics are not administered is reasonable.
How to Test the Urine
Once you’ve decided to order a urinalysis, the question is how best to obtain the sample. In the 2– to 24-month age group, the AAP guidelines suggest two options: obtain urine either through catheterization or suprapubic aspiration for culture and urinalysis or through the most convenient means to perform a urinalysis.3 If the urinalysis suggests a UTI (leukocyte esterase or nitrite test positive, or microscopic analysis results for leukocytes or bacteria), then a second urine specimen should be obtained through catheterization or suprapubic aspiration and cultured. Specimens obtained via urine bag have been shown to be effective to exclude UTI diagnosis; however, urine bags should not be sent for culture due to high risk of contamination.7 All positive urine bag dipsticks/urinalyses must be confirmed with a catheterized or midstream specimen before sending for culture.
As we all know, infants do not produce urine on command in the emergency department. To help speed up the clean catch process (while obtaining a sample less prone to contamination), two effective methods have been described. The Quick-Wee Method involves gentle suprapubic cutaneous stimulation (circular movement) using gauze soaked in cold fluid (for infants ages 1–12 months) until the clean catch urine is obtained.7
The Bladder Tap Technique involves three providers.8 The patient is fed 25 minutes prior. One provider gently taps the suprapubic area, at a rate of 100 taps per minute, for 30 seconds. The other provider then massages the lumbar paravertebral area in the lower back for 30 seconds. Both maneuvers are repeated until the third provider collects a clean catch urine sample.
There is little, if any, role for imaging in the emergency department for pediatric UTI. The latest AAP guideline no longer recommends voiding cystourethrograms after a single UTI. AAP and Canadian Paediatric Society guidelines both recommend children <2 years of age should be investigated with a renal bladder ultrasound after their first febrile UTI to identify any significant renal abnormalities (albeit a level C recommendation).2,9 There is no convincing evidence suggesting that ultrasound improves patient-oriented outcomes, and ultrasound imaging may lead to further invasive testing that can cause harm.
My hope is that if we all think carefully about the predictive value of the clinical features of pediatric UTI, less unnecessary testing will occur. Consider using the UTI calculator and treating appropriately with antibiotics only when truly indicated and without imaging. By doing this, we can collectively reduce the harms that we are currently causing by overtesting, overdiagnosing, and overtreating pediatric UTI.
Special thanks to Dr. Michelle Science and Dr. Olivia Ostrow for their contributions to the EM Cases podcast that inspired this article.