Surgical Aspects of Urinary Tract Infections

The surgical significance of urinary tract infections (UTIs) in children Marisa Seepersaud MBBS MRCS DM

2011 (Sarah Amin) 

Records were poor

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22 patients , age 5 and under , who were treated for UTI at the GPHC

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Urinalysis: All Urine culture: 4/22 (18%)

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Abdominal ultrasound: 7/22 (32%) (2 “enlarged kidneys”, 5 Normal study)

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2 referrals to urology1 PUV

Brandon Seepersaud

Urinary Tract Infection (UTI) 

UTIs are among the most common bacterial infections in children under 2 yrs old

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The diagnosis is often missed on history and physical examination

Recent Recommendations 

AAP, American Academy of Pediatrics , (1999) 2013

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Consensus Document, Management of UTI in Jamaican Children, (2005), August 2011

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NICE, National Institute for Health and Care Excellence, UK (2007) May 2011

Incidence 

~1% of children below age 1

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~ 5 % of febrile children*, 2- 24 months of age

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7.5% girls, 10% uncircumcised males, 2.5% of circumcised males who present with a fever under 2yrs

Clinical significance of UTI 

Associated with life-threatening sepsis in the newborn

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Increased rates of renal scarring in young children hypertension chronic kidney disease  pregnancy induced hypertension

Urinary tract infections may occur as a result of structural anomalies of the urinary tract

The diagnosis of urinary tract infection in a young child is an important marker for urinary tract abnormalities Mandates investigation

Important to accurately make the diagnosis

Under-diagnosing UTI may lead to under-treatment, underinvestigation, and risks permanent renal damage

Risk of renal scarring with recurrent UTI Jodul U. The natural history of bacteriuria in childhood. Infect Dis Clin North Am. 1987;1(4):713–729

100% 80% 60% 40% 20% 0% 1

2

3

4

5

Important to accurately make the diagnosis Over-diagnosing UTI may result in the development of resistant organisms, the use of limited resources for unnecessary and expensive investigations, (uncomfortable/painful/ scary for patient; distressing for the parents)

Age group

Symptoms and signs Most common

Infants younger than 3 months

Infants older Preverbal than 3 months, and children

Verbal



Least common

Fever Vomiting Lethargy Irritability

Poor feeding Failure to thrive

Fever

Abd pain Vomiting Poor feeding Loin tenderness

Lethargy Irritability Haematuria Malodorous urine Failure to thrive

Frequency Dysuria

Dysfunctional voiding Sec enuresis Abd pain Loin tenderness

Fever Malaise Vomiting Haematuria Malorous urine Cloudy urine

Who should be screened for a UTI? 

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Infants and children with symptoms and signs of UTI

Infants* with 1 or more of the following: temperature of at least 38°C fever for at least 2 days absence of another obvious source of infection

Option 

If the patient does not require immediate antimicrobial treatment

 period of observation prior to investigation and treatment for UTI

Dipstick screening of fresh urine Both leukocyte esterase and nitrite POSITIVE

UTI Send urine for culture May start antibiotics

Leukocyte esterase : negative Nitrite : positive

Send urine for culture

Leukocyte esterase : positive Nitrite : negative

Send urine for culture

Leukocyte esterase : negative Nitrite : negative

UTI unlikely

Diagnosis 

Must involve urine culture

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Traditionally: >100,000 cfu/ml

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Issues: contamination, false negatives, false positives

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Asymptomatic bacteriuria

Asymptomatic Bacteriuria (AS) Colonization of the urinary tract with non-pathogenic organisms Study of 3581 infants  2.5% male infants, 0.9% female infants  2 patients with AS developed symptomatic UTI soon after  None of the other patients who developed UTI in the first year of life were found to have AS at initial screening Another study involving school aged girls with AS  No difference in renal growth or function when patients were randomised to treatment vs observation  But the treated group appeared to be more likely to develop pyleonephritis after antibiotics were stopped

Diagnosis of UTI: 2013 AAP recommendations 

Presence of both >50 000cfu/ml of a single organism/uropathogen AND

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Pyuria

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In an appropriately collected specimen

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Febrile 2-24 month olds who have no obvious neurologic or anatomic abnormalities known to be associated with rec UTI or renal damage (may be extrapolated to under 5yr old)

Investigation of UTI: Culture 

Urine collected in a bag

- only valid if NEGATIVE - cannot be used to make a diagnosis of UTI - positive culture is likely to be false positive (88%) ! - positive culture requires confirmation, which is impossible if antibiotics were started*

REMEMBER: You want the most accurate test to be done initially since urine may be rapidly sterilised

Appropriate methods 

Catheter specimen urine (CSU)

 sensitivity: 95%  specificity: 99%  difficult in young girls*

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Suprapubic Aspiration/ Bladder Tap (SPA)

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MSU in older patients

Diagnosis 

Urinalysis is Positive when: Dipstick nitrite leukocyte esterase test Microscopy  white blood cells/pus cells

 +/- bacteria

The urinalysis may be negative despite a positive culture:  

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Contamination Asymptomatic bacteriuria Urinalysis is not sensitive enough

Requires 4 hrs of “stasis” in the bladder Young children, infants and neonates may void more often

Treatment 

Initiating treatment orally or parenterally is equally efficacious, so choice is based on practical considerations.

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Choice of drug should be based on local sensitivity patterns, adjusted according to sensitivity of particular uropathogen

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Duration of treatment: 7–14 days

EVERY CHILD, who has had a diagnosis of a urinary tract infection, must be investigated for the presence of a predisposing anatomic abnormality of the urinary tract

Investigation 

~5% of patients will be found to have some abnormality on investigation

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~16% of patients with febrile UTI

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Overall about 1-2% of cases will be determined to have “actionable” findings which require some intervention.

Should patients be put on prophylaxis while awaiting investigations? 

YES

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No

Parental education 

Implications/complications of a UTI

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Symptoms/signs of a recurrent UTI

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Need for a urine culture for future febrile illnesses , even when there is an apparent source of fever

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Instructed to seek prompt medical evaluation for future febrile illnesses to ensure that recurrent infections can be detected and treated promptly

Imaging Investigations for UTI 

Abdominal Ultrasound

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MCUG/VCUG

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Renal scan (DMSA)

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Intravenous Pyelogram (IVP)

Investigation: KUB USS 

All patients diagnosed with UTI should undergo kidney/ureter/bladder sonography (KUB USS)

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Timing: 6weeks post treatment

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Exception: if

patient is not responding to treatment as expected, unusually ill  KUB USS within 48hrs

Micturating/Voiding cystourethrogram (MCUG/VCUG) 

MCUG is not recommended routinely after the first febrile UTI if KUB USS is normal. Schroeder AR, Abidari JM, Kirpekar R, et al. Impact of a more restrictive approach to urinary tract imaging after febrile urinary tract infection. Arch Pediatr Adolesc Med. 2011;165(11):1027–1032

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Recommended in the presence of  an abnormal KUB USS  recurrent UTI  atypical UTI

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MCUG done 4-6 weeks after the UTI Look at the films , incl post micturation films

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Renal Scan/ Radionucleotide Scan (RNC) May be used in the acute setting to diagnose pyleonephritis  Helpful in distinguishing between obstructive and nonobstructive causes of hydronephrosis

Provides information on differential function  Indentify renal cortical defects (DMSA)

IVP is useful in the absence of the RNC

All patients with UTI’s should have: Urine culture  Urinalysis  Abdominal Ultrasound 

+/- MCUG  +/- Renal scan  +/- IVP (in the absence of renal scan) 

What about long term urinary prophylaxis following UTI? 

Urinary prophylaxis is dictated by the underlying pathology

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Antibiotic prophylaxis should not be recommended in infants and children after the first UTI (if no underlying abnormality was found )

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May be considered in infants and children with recurrent UTI

Dysfunctional elimination syndromes and constipation should be addressed in infants and children who have had a UTI.

Normal Cystogram (MCUG)

Normal Bladder and Urethra

Posterior urethral valves (PUV)

Posterior urethral valves

Bladder Diverticulum

Bladder diverticuli

Detrusor Instability

Grade I Vesicoureteric Reflux (VUR)

Grade II Vesicoureteric Reflux (VUR)

Grade IV Vesicoureteric Reflux (VUR)

Contrary to previous beliefs 

“VUR with UTI without structural abnormalities in the kidneys seems not to cause CKD.”

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“Active treatment of VUR seems not to reduce the occurrence of CKD and, in large prospective follow-up studies, the renal function of patients with VUR has been well preserved.”

Salo J, Ikäheimo R, Tapiainen T, et al. Childhood urinary tract infections as a cause of chronic kidney disease. Pediatrics. 2011;128(5):840–847

Recurrence of UTI in patients with VUR prophylaxis vs observation Prophylaxis Reflux Grade

No Prophylaxis

N

P

# of Recurrences / Total N

# of Recurrences / Total N

None

373

7 / 210

11 / 163

0.15

Grade I

72

2 / 37

2 / 35

1.00

Grade II

257

11 / 133

10 / 124

0.95

Grade III

285

31 / 140

40 / 145

0.29

Grade IV

104

16 / 55

21 / 49

0.14

Grade V Vesicoureteric Reflux (VUR)

Recurrence rate of febrile UTI in ages 2-24 months

100% 80% Prophylaxis 60%

No Prophylaxis

40% 20% 0% None

Grade I

Grade II

Grade III

Grade IV

Normal Intravenous Pyelogram (IVP)

Pelviureteric Junction (PUJ) Obstruction

Urolithiasis

Who should be referred to the paediatric nephrologist/ paediatric urologist/ paediatric surgeon?  

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Poor response to treatment of UTI/uncertainties of Mx Recurrent UTI Neurogenic bladder Voiding dysfunction Symptoms of dysfunctional elimination syndrome Hydronephrosis (obstructive or non obstructive; intrauterine or post natal) Abnormal radiology (KUB USS, MCUG, Renal scan) Suspicious looking radiology even if reported as normal Renal scarring Obstructive uropathy (antenatally or postnatally diagnosed)

Role of Circumcision 

Presence of foreskin does not worsen UTI or increase risk of UTI once there is proper hygiene

Role of Circumcision Circumcision has a limited role in treatment of UTI: 1. 2.

Recurrent UTI with no other abnormality Solitary hydronephrotic kidney

Summary: Diagnosis/Mx UTI 

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Diagnosis – Abnormal urinalysis as well as positive culture – Positive culture = ≥50,000 colony-forming units (cfu)/ml Treatment - Oral as effective as parenteral Imaging - KUB USS for all patients - Voiding cystourethrography (VCUG) not recommended routinely after first febrile UTI; required if KUB USS is abnormal; necessary for recurrent and atypical UTI Follow up – Emphasis on urine testing with subsequent febrile illnesses Referral – Early referral to paediatric surgery (paedi urology /nephrology)

Thank You.