Rosen & Barkin's 5-Minute Emergency Medicine Consult (746 page)

DIAGNOSIS

• Often nonspecific
  
• Neonates:
  
  • Manifestations of sepsis
    
  • Feeding difficulties
    
  • Irritability, listlessness
    
  • Fever, hypothermia
    
• 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
    
• Complications:
  
  • Recurrent UTI
    
  • Pyelonephritis
    
  • Chronic renal failure:
    
    • Scarring probably may be reduced by early detection and intervention
      
  • Perinephric abscess
    
  • Bacteremia/sepsis
    
  • Urolithiasis
    

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

• 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 common
    
  • Gram 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 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.
    

• 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.
    

• Children requiring radiologic evaluation:
  
  • Infants <3 mo of age
    
  • Males (increased association with anomaly) with 1st UTI
    
  • Clinical signs and symptoms consistent with pyelonephritis
    
  • Clinical evidence of renal disease
    
  • Some suggest that girls <3 yr of age with a 1st UTI should be studied.
    
  • Females >3 yr of age
    
  • 1st 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 therapy
    
  • 2nd 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
    

• Infection:
  
  • Vulvovaginitis
    
  • Viral cystitis
    
  • Urethritis (
    Neisseria gonorrhoeae or Chlamydia trachomatis
    )
    
  • Glomerulonephritis
    
  • Appendicitis
    
• Trauma:
  
  • Chemical irritation/cystitis
    
  • Perineal
    
  • Sexual abuse
    
  • Genitourinary
    
  • Masturbation
    
  • Foreign body
    
• Nephrolithiasis
  
• Diabetes
  

TREATMENT

• 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
  

• Initiate IV antibiotics in all febrile infants <3 mo with UTI:
  
  • Ampicillin and gentamicin in neonates
    
  • Cephalosporins 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:
  
  • 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.
    

• 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

• 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
  

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

• 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.
  

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