Urinary tract infection in infants and children: Diagnosis and management Flashcards
What percentage of children 2-24mo with fever without a source were diagnosed with UTI?
7%
What percentage of children 2-19yo with possible urinary symptoms were diagnosed with UTI?
8%
What is the rate of UTI in uncircumcised febrile boys <3mo?
20.7%
What is the rate of UTI in circumcised febrile boys <3mo?
2.4%
What is the rate of UTI in uncircumcised febrile boys 6-12mo?
7.3%
What is the rate of UTI in circumcised febrile boys 6-12mo?
0.3%
What is the rate of UTI in febrile girls <3mo?
7.5%
What is the rate of UTI in febrile girls 3-6mo?
5.7%
What is the rate of UTI in febrile girls 6-12mo?
8.3%
What is the rate of UTI in febrile girls 12-24mo?
2.1%
When should a urinanlysis and urine culture be obtained?
Children <3yo with a fever (>39 degrees rectal) with no apparent source
Children >3yo with urinary symptoms
Should febrile children 2mo-3yo with rhinitis, cough, wheeze, rash, or diarrhea need to be investigated for UTI?
No
What features predispose girls to URI?
- <12mo
- White race
- Temperature >39
- Fever >2d
- Absence of another source of fever
Children with no more than one of these features have <1% risk of UTI
What is the contamination rate of bag samples?
63%
What are recommended methods of obtaining urine samples from non-toilet trained children?
- Urethral catheterization
- Suprapubic aspiration
- Leaving the diaper off and obtaining a clean-catch urine when child voids
What is the recommended method of obtaining urine samples from a toilet trained child?
Clean catch
What is the specificity and specificity of components of the urinanalysis in predicting UTI?
- Leukocyte esterase (LE) 83% sens 76% spec
- Nitrites (NT) 53% sens 98% spec
- Either LE or NT positive 93% sens 72% spec
- Microscopy WBC 73% sens 81% spec
- Microscopy bacteria 81% sens 83% spec
- LE, NT, or microscopy positive 99.8% sens 70% spec
What are the minimum colony counts that are indicative of a UTI?
- Clean catch >10^5 CFU/mL or >10^8 CFU/L
- In and out catheter specimen >5x10^4 CFU/mL or >5x10^7 CFU/L
Mixed growth = contamination
- Suprapubic aspiration any growth
When should blood cultures be drawn in a child with a UTI?
If child is hemodynamically unstable
When should renal function be monitored in a child with UTI?
Complicated UTI
Treatment with aminoglycosides >48h
What is the recommended empiric treatment for febrile UTI in non-toxic children with no structural urological abnormalities?
Cefixime PO x 10-14d
What is the recommended empiric therapy for febrile UTI in hospitalized children?
IV gentamicin +/- IV ampicillin
Consider cefotaxime or ceftriaxone due to nephrotoxicity of gentamicin
What is the recommended empiric therapy for non-febrile UTI (cystitis) with urinary symptoms?
PO antibiotics x 2-4d cover E coli
When to be concerned that a child has complicated UTI?
- Hemodynamically unstable
- Elevated serum Cr level
- Bladder or abdominal mass
- Poor urine flow
- Not improving clinically within 24h
- Fever not trending down within 48h of antibiotics
What are the recommendations for complicated UTI?
US to r/o obstruction or abscess
IV antibiotics
What should one do if a multiresistant organism is isolated in urine?
May use quinolones if organism is resistant to all other oral antibiotics
If clinical improvement and patient asymptomatic consider repeating urine culture and not changing antibiotics
What parenteral antibiotics are commonly used to treat UTIs in children >2mo if isolate is susceptible?
Ampicillin IV Ceftriaxone IV/IM Cefotaxime IV/IM Gentamicin IV/IM Tobramycin IV
What oral antibiotics are commonly used to treat UTIs in children >2mo if isolate is susceptible?
Amoxicillin Amoxi-clav SMX/TMP Cefixime Cefprozil Cephalexin Ciprofloxacin
When should a RBUS be performed?
US in <2yo with first febrile UTI within 2wks of acute illness
When should VCUG be obtained?
- <2yo with second well-documented UTI
2. RBUS suggestive of selected renal abnormalities, obstruction, or high grade VUR
When can a nuclear cystogram (NCG) be used?
In place of VCUG in initial test for females and in follow-up studies for both sexes
What will nuclear cystograms (NCG) miss?
Posterior urethral valves
When can a DMSA scan be used?
Diagnose acute pyelonephritis and to identify renal scars
What are the recommendations regarding UTI?
- 2-36mo with fever >39°C and no other source should have urine collected by catheter or suprapubic aspirate sent for culture. May use bag urinalysis to screen.
- In toilet trained child use midstream urine for R&M and C&S.
- Children with possible UTI who require antibiotic treatment immediately for other indications, such as suspected bacteremia, should have urine collected for urinalysis, microscopy and culture. The test sample should be midstream urine if the child is toilet trained, and a catheter or SPA or clean-catch specimen if not, and obtained before starting antibiotics.
- Overdiagnosis of UTI is a common problem, leading to overuse of antibiotics and unnecessary imaging.
- Urines collected by bag should never be used for diagnosis of UTI. Urines with low colony counts, mixed growth or no pyuria are usually contaminated.
- Infants and children with febrile UTI should be treated with antibiotics for seven to 10 days. Oral antibiotics can be administered as initial treatment when the child has no other indication for admission to hospital and is considered likely to receive and tolerate every dose.
- There is no evidence that children with UTIs and documented bacteremia who have a rapid clinical response to antibiotics require intravenous antibiotics or a longer course of antibiotics. However, all such children need to be assessed by a physician the day that the blood culture is known to be positive. The choice of antibiotic should be guided by the resistance pattern of common urinary pathogens in the community and changed to a less broad spectrum agent, if practical, when the sensitivity of the pathogen is known.
- Children <2 years of age should be investigated after their first febrile UTI with a renal and bladder ultrasound (RBUS) to identify significant renal abnormalities and grade IV or V VUR. A voiding cystourethrogram (VCUG) is not indicated with a first febrile UTI when the RBUS is normal.
- Antibiotic prophylaxis is no longer recommended for grades I through III VUR or pending results of the initial RBUS.
- Children with grade IV or V VUR or a significantly abnormal RBUS should be discussed with a paediatric urologist or nephrologist to determine whether there is an urgent need for a consult and make the best plan for further investigation and management.
- Parents of all children with febrile UTIs, with or without VUR, should be advised that their child needs to be assessed for the possibility of recurrent UTI early in the course of any unexplained fever. Such guidance is especially pertinent in this era, where very few children are on prophylactic antibiotics for UTIs.
- For older children with no fever and presumed cystitis, a two- to four-day course of oral antibiotics is usually adequate.
What future research is needed for optimal management of UTI in children?
- Long-term cohort studies to establish the relationship between UTI in infants and young children and reduced renal function and hypertension in adults.
- Less invasive techniques for diagnosis of VUR and better understanding of the contribution of VUR and other risk factors to the development of renal function abnormalities.
- Assessment of optimal treatment strategies (length of therapy, choice of antibiotics) for febrile UTIs and for older children with cystitis.
- Management strategies for infants <2 months of age with UTIs
