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Urinary Tract Infections, Pediatric, Emergency Medicine

Basics

Description

- Bacteria colonize via retrograde contamination of rectal or perineal flora: - Infants " ”often hematogenous spread - Older children " ”vesicoureteral reflux (VUR) major risk

- UTI is defined by culture of a single organism of >10,000/mL on a catheterized or suprapubic specimen. Other collection techniques are not routinely used in young children for definitive diagnosis. - In infants 0 " “3 mo old, UTI is associated with a 30% incidence of sepsis. - Predisposing factors: - Poor perineal hygiene - Short urethra of female - Female > male - Infrequent voiding - Constipation - Sexual activity - Male circumcision probably reduces risk

- 1 mo " “3 yr of age: - Fever - Irritability - Vomiting, diarrhea - Abdominal pain - Poor feeding, failure to thrive

- Hematuria - In girls <2 yr, an increased risk is associated with those having ≥3 factors (<12 mo old, white, temperature ≥39 ‚ °C, absence of other source of fever, fever ≥2 days) - Children >3 yr of age: - Dysuria - Frequency - Enuresis - New onset of urinary incontinence - Pain: Abdominal, suprapubic, back, costovertebral angle (CVA) - Fever - Hematuria - Malodorous cloudy urine - Systemic toxicity: High fever and chills with CVA tenderness

- Perinephric abscess - Bacteremia/sepsis - Urolithiasis

- Clean-catch and bag specimens - Clean catch in cooperative male children - Plastic bag collection adequate for UA (70% contamination rate). - Clean the perineum (females) and glans (males) before application. - Can be used as a screening tool to rule out an infection if patient is not placed on antibiotics empirically and follow-up culture possible if the initial assessment is suggestive of infection.

- Catheterization is the preferred technique to obtain urine because contamination is common with bag collection and clean catch: - Bladder catheterization: - Acceptable in all infants - Higher success rate than suprapubic aspiration - Aseptic technique essential - Discarding the 1st 1 " “2 mL of urine before collecting specimen reduces contamination.

- Suprapubic aspiration is used on rare occasion and does provide a good specimen: - Most useful in infants - Full bladder optimal - Uncommonly used - Ultrasound may be useful adjunctive measure to improve yield.

- Outpatient oral antibiotic for 10 " “14 days for children discharged. Should reflect local resistance patterns. Once sensitivity is known, antibiotic may need to be changed: - Amoxicillin - Amoxicillin/clavulanate - Cephalexin - Trimethoprim " “sulfamethoxazole (TMP " “SMX) - Many suggest 3rd-generation cephalosporin (cefixime, cefdinir) as 1st-line drug in treatment of children without GU anomaly because of changing resistance patterns. Oral therapy is generally adequate although close follow-up is essential to monitor clinical response and sensitivity of the etiologic organism. - Recent UTI may provide information related to sensitivities in children with recurrent UTIs - Length of treatment in children with afebrile UTI may be shortened to 5 days in children >2 yr. The short course is still not generally recommended in children with febrile UTI.

  • Bacteria colonize via retrograde contamination of rectal or perineal flora:Infants " ”often hematogenous spreadOlder children " ”vesicoureteral reflux (VUR) major risk
  • UTI is defined by culture of a single organism of >10,000/mL on a catheterized or suprapubic specimen. Other collection techniques are not routinely used in young children for definitive diagnosis.
  • In infants 0 " “3 mo old, UTI is associated with a 30% incidence of sepsis.
  • Predisposing factors:Poor perineal hygieneShort urethra of femaleFemale > maleInfrequent voidingConstipationSexual activityMale circumcision probably reduces risk

Etiology

  • UTI found in 4 " “7% of febrile infants
  • Bacterial agents:Escherichia coli accounts for 80%Klebsiella pneumoniaeStaphylococcus aureusEnterobacter speciesProteus speciesPseudomonas aeruginosaEnterococcus species

Diagnosis

UTIs in children may be difficult to diagnose without lab confirmation. ‚

Signs and Symptoms

History

  • Often nonspecific
  • Neonates:Manifestations of sepsisFeeding difficultiesIrritability, listlessnessFever, hypothermia
  • 1 mo " “3 yr of age:FeverIrritabilityVomiting, diarrheaAbdominal painPoor feeding, failure to thrive
  • Hematuria
  • In girls <2 yr, an increased risk is associated with those having ≥3 factors (<12 mo old, white, temperature ≥39 ‚ °C, absence of other source of fever, fever ≥2 days)
  • Children >3 yr of age:DysuriaFrequencyEnuresisNew onset of urinary incontinencePain: Abdominal, suprapubic, back, costovertebral angle (CVA)FeverHematuriaMalodorous cloudy urineSystemic toxicity: High fever and chills with CVA tenderness
  • Complications:Recurrent UTIPyelonephritisChronic renal failure:Scarring probably may be reduced by early detection and interventionPerinephric abscessBacteremia/sepsisUrolithiasis

Physical Exam

  • Vital signs, esp. temperature and blood pressure
  • Toxicity
  • Growth parameters
  • Abdomen: Tenderness, esp. CVA pain
  • GU: Genitalia

Essential Workup

  • UA with microscopic RBC and WBC counts and Gram stain for bacteria:UA alone has low diagnostic sensitivity in infants.Causes of pyuria besides UTI include chemical (bubble bath) or physical (masturbation) irritation, dehydration, renal tuberculosis, trauma, acute glomerulonephritis, respiratory infections, appendicitis, pelvic infection, and gastroenteritis.Leukocyte esterase correlates with presence of pyuria.Positive nitrite test indicates presence of bacteria capable of fixing nitrate. False-negative tests commonGram stain of urinary sediment is more reliable than dipstick methods of diagnosis and superior to traditional UA.Up to 80% of UAs in neonates with documented UTIs may be normal.
  • Urine culture:Specimen should be cultured within 30 min or refrigerated.False-negative results may be caused by dilution, improper culture medium, recent antimicrobial therapy, fastidious organisms, bacteriostatic agent in urine, and complete obstruction of ureter.
  • Clean-catch and bag specimensClean catch in cooperative male childrenPlastic bag collection adequate for UA (70% contamination rate).Clean the perineum (females) and glans (males) before application.Can be used as a screening tool to rule out an infection if patient is not placed on antibiotics empirically and follow-up culture possible if the initial assessment is suggestive of infection.
  • Catheterization is the preferred technique to obtain urine because contamination is common with bag collection and clean catch:Bladder catheterization:Acceptable in all infantsHigher success rate than suprapubic aspirationAseptic technique essentialDiscarding the 1st 1 " “2 mL of urine before collecting specimen reduces contamination.
  • Suprapubic aspiration is used on rare occasion and does provide a good specimen:Most useful in infantsFull bladder optimalUncommonly usedUltrasound may be useful adjunctive measure to improve yield.

Diagnosis Tests & Interpretation

Lab

  • CBC and blood culture for young children with fever or nonspecific symptoms and no source on exam. Consider additional evaluation as appropriate.
  • Electrolytes, BUN, creatinine:Check if there is dehydration, pyelonephritis, or recurrent infection.

Imaging

  • Children requiring radiologic evaluation:Infants <3 mo of ageMales (increased association with anomaly) with 1st UTIClinical signs and symptoms consistent with pyelonephritisClinical evidence of renal diseaseSome suggest that girls <3 yr of age with a 1st UTI should be studied.Females >3 yr of age1st UTI in patients who have a family history of UTIs, abnormal voiding pattern, poor growth, HTN, urinary tract anomalies, or failure to respond promptly to therapy2nd UTI
  • Voiding cystoureterogram (VCUG):UTI is often associated with VUR and other genitourinary abnormalities and identified by VCUG. The importance of identifying VUR has been questioned.
  • Renal/bladder ultrasound (US):Ultrasonography is useful in excluding obstructive lesion and identifying children with solitary/ectopic kidney and some patients with moderate renal damage/scarring:Renal/bladder US is indicated to identify anatomic abnormalities. Should be done in children <2 yr with 1st febrile UTI, children with recurrent febrile UTIs, children with a UTI and family history of GU disease, poor growth, or hypertension as well as those children who do not respond as anticipated to antibiotics.Nuclear cystogram (DMSA) may be substituted for VCUG in females. Its role is being clarified.Further evaluation with nuclear medicine studies depends upon the grade of VUR and response to treatment

Differential Diagnosis

  • Infection:VulvovaginitisViral cystitisUrethritis (Neisseria gonorrhoeae or Chlamydia trachomatis)GlomerulonephritisAppendicitis
  • Trauma:Chemical irritation/cystitisPerinealSexual abuseGenitourinaryMasturbationForeign body
  • Nephrolithiasis
  • Diabetes

Treatment

Initial Stabilization/Therapy

  • Treat infants <3 mo old presumptively for sepsis if febrile and/or toxic until blood and other appropriate cultures are final.
  • Airway intervention for septic/acidotic infants with depressed respiratory drive
  • Bolus of 20 mL/kg 0.9% NS for dehydration, hypovolemia, or sepsis; may repeat

Ed Treatment/Procedures

  • Initiate IV antibiotics in all febrile infants <3 mo with UTI:Ampicillin and gentamicin in neonatesCephalosporins after 4 " “8 wk of age
  • Outpatient oral antibiotic for 10 " “14 days for children discharged. Should reflect local resistance patterns. Once sensitivity is known, antibiotic may need to be changed:AmoxicillinAmoxicillin/clavulanateCephalexinTrimethoprim " “sulfamethoxazole (TMP " “SMX)Many suggest 3rd-generation cephalosporin (cefixime, cefdinir) as 1st-line drug in treatment of children without GU anomaly because of changing resistance patterns. Oral therapy is generally adequate although close follow-up is essential to monitor clinical response and sensitivity of the etiologic organism.Recent UTI may provide information related to sensitivities in children with recurrent UTIsLength of treatment in children with afebrile UTI may be shortened to 5 days in children >2 yr. The short course is still not generally recommended in children with febrile UTI.

Medication

First Line

  • Amoxicillin: 40 mg/kg/24 h PO q8h
  • Amoxicillin/clavulanate: 40 mg/kg/24 h PO q8h
  • Ampicillin: 100 mg/kg/24 h IV q6h
  • Cefdinir 14 mg/kg/24 h PO QD
  • Cefixime 16 mg/kg/24 h PO on 1st day followed by 8 mg/kg/24 h PO QD
  • Ceftriaxone: 50 " “75 mg/kg/24 h q12 " “24h IV or IM
  • Cephalexin: 50 mg/kg/24 h PO q6 " “12h
  • Gentamicin: 2.5 mg/kg/dose IV q8h if full-term and age >7 days; 2.5 mg/kg/dose IV q12h if full-term and age 0 " “7 days (special dosing regimens in infants <36 wk postconceptual age)
  • TMP " “SMX (Bactrim or Septra suspension): 5 mL liquid (of 40/200 per 5 mL) per 10 kg per dose PO BID

Follow-Up

Disposition

Admission Criteria

  • Infants <3 mo
  • Dehydration
  • Ill appearance/toxicity/sepsis
  • Suspected pyelonephritis
  • Urinary obstruction
  • Vomiting, inability to retain medications
  • Failure to respond to outpatient therapy
  • Immunocompromised patient
  • Renal insufficiency
  • Foreign body (indwelling catheter)
  • Pregnant patient

Discharge Criteria

  • Sufficiently hydrated
  • Low risk for sepsis or meningitis
  • Nontoxic
  • Able to take oral antibiotics; compliant

Issues for Referral

  • Patients needing admission often require a pediatrician, urologist, or infectious disease consultant, esp. if there is VUR, renal anomaly, impaired renal function, recurrent infection, or hypertension.
  • Good follow-up is mandatory.

Followup Recommendations

Monitoring of urine for sterility, further evaluation for underlying pathology, and following growth pattern ‚

Pearls and Pitfalls

  • UTI may require lab confirmation of clinical suspicion. Signs and symptoms are often nonspecific.
  • Febrile infants with UTI may be bacteremic.
  • Neonates with UTI may have normal urinalysis.

Additional Reading

  • American Academy of Pediatrics, Subcommittee on Urinary Tract Infection. Urinary tract infection: Clinical practice guidelines for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. Pediatrics. 2011;128:595 " “610.
  • Hoberman ‚ A, Keren ‚ R: Antimicrobial prophylaxis for urinary tract infection in children. N Engl J Med. 2009;361:1804 " “1806.
  • Marks ‚ SD, Gordon ‚ I, Tulls ‚ K. Imaging in childhood urinary tract infection: Time to reduce investigations. Pediatr Nephrol. 2008;23:9 " “17.
  • Peniakov ‚ M, Antonelli ‚ J, Naor ‚ O, et al. Reduction of contamination of urine samples obtained by in-out catheterization by culturing the later urine stream. Pediatr Emerg Care. 2004;6:418 " “419.
  • Sahsi ‚ RS, Carpenter ‚ CR. Does this children have a urinary tract infection? Ann Emerg Med. 2009;53:680 " “684.
  • Wald ‚ E. Urinary tract infections in infants and children: A comprehensive overview. Curr Opin Pediatr. 2004;16:85 " “88.

See Also (Topic, Algorithm, Electronic Media Element)

UTI, Adult ‚

Codes

ICD9

  • 041.49 Other and unspecified Escherichia coli [E. coli]
  • 593.70 Vesicoureteral reflux unspecified or without reflux nephropathy
  • 599.0 Urinary tract infection, site not specified
  • 041.3 Klebsiella pneumoniae
  • 599.70 Hematuria, unspecified

ICD10

  • B96.20 Unsp Escherichia coli as the cause of diseases classd elswhr
  • N13.70 Vesicoureteral-reflux, unspecified
  • N39.0 Urinary tract infection, site not specified
  • B96.1 Klebsiella pneumoniae as the cause of diseases classd elswhr
  • R31.9 Hematuria, unspecified

SNOMED

  • 68566005 urinary tract infectious disease (disorder)
  • 197811007 vesicoureteric reflux (disorder)
  • 301011002 Escherichia coli urinary tract infection (disorder)
  • 186435004 Friedlanders bacillus infection (disorder)
  • 34436003 Blood in urine (finding)