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Pediatric UTIs

General considerations and risk factors

• UTI is cause of 7% febrile infections in infants, 8% if > 24mo
• Bacteremia present in 7-13% with fever
• If < 24mo, fever > 40, hx UTI, SP tenderness, and uncircumcised penis are most predictive of UTI in a febrile child
• Age/gender: 2.7% boys vs 0.7% have a UTI during 1st year, then 0.03%-0.2% boys vs 1-3% girls per year after 1st year
• Circumcision in 1st 6mo of life decreases rates x10 - 111 otherwise-normal boys need to be circumcised to prevent one UTI, but only 11 if hx UTI, only 4 if hx high grade VUR
• Other risk factors: vesicoureteral reflux, neurogenic bladder, bowel/bladder dysfunctoin

Imaging for UTI

• Renal US: obtain if febrile UTI, < 6mo, or > 6mo and atypical UTI
• VCUG: obtain if abnormal RUS, 2+ febrile UTI, UTI in circumcised boy, or abnormal UTI, can perform as soon as asymptomatic and urine is sterile, cycling study recommended (more sensitive)
• DMSA scan: consider if atypical UTI, may need to wait 1-2yrs to assess scarring

Treatment considerations

• Indications for inpatient management: age < 1mo (some say < 2-6mo), toxic appearance, not tolerating PO intake, concerns for antibiotic compliance
• Consider renal US if no improvement within 48hrs
• Duration: treat for 7-14 days, longer for severe infections
• Age considerations: avoid TMP/SMX if < 6 weeks, avoid nitrofurantoin if < 3mo

Other Infections

• Viral cystitis: more common in immunosuppressed situations, can have 50-80% mortality rate without treatment
• Funguria: more common with catheterization or prior antibiotic therapy, consider imaging to assess for fungal balls

Antibiotics for UTI

Antibiotic	Dosing	N/V/D	Rash	Other side effects
Nitrofurantoin	3-5mg/kg/d, BID	Yes	No	Hyperbilirubinemia if given < 3mo old
TMP/SMX	8-10mg/kg/d (trimethoprim), BID		Yes	Photosensitivity
Augmentin	20-40mg/kg/d, TID			No
Cephalexin	50-100mg/kg/d, QID			Headache, diarrhea
Cefprozil	20mg/kg/d, BID

Vesicoureteral reflux (VUR)

Considerations

• Primary reflux: congenital defect in UVJ structure, normal bladder function
• Secondary reflux: due to either elevated intravesical pressures or anatomically abnormal UVJ
• May be neurogenic, bowel/bladder dysfunction (BBD), detrusor overactivity
• BBD increases risk for breakthrough UTIs while on prophylaxis (45% vs 15%) and after VUR repair
• VUR does not cause UTI, but does allow rapid infection of upper tract
• Megacystis/megaureter: bladder dilation secondary to constant emptying to upper tracts, can be diagnosed prenatally, manage with vesicostomy and eventual VUR treatment
• Reflux nephropathy: triad of renal scarring, hypertension, and reflux
• Women with history VUR have increased risk for morbidity, even if prior VUR treatment
• Spontaneous resolution: Grade 2 (63-85%), Grade 3 (50%), Grade 4-5 (9-38%)
• Indications for newborn VCUG: high grade hydronephrosis (especially bilateral), renal cortical abnormalities, ureteral dilation, suspected ureteroceles or duplication, and bladder abnormalities
• Evaluation: obtain height/weight, vitals, creatinine level, urinalysis, renal US - DMSA is optional
• THE KEY: renal injury caused by upper tract infection, minimizing reflux will prevent cystitis from becoming pyelonephritis and leading to renal scarring

Tenets of VUR management

• Goals: prevent febrile UTI, prevent renal injury, minimize treatment morbidity
• Spontaneous resolution is common and more likely to improve with simultaneous BBD treatment
• VUR less likely to resolve if higher grade or older age
• Sterile reflux unlikely to cause significant damage
• UTI prevention more important than VUR resolution
• Antibiotic prophylaxis is safe/beneficial
• Most forms can be managed medically

Antibiotic prophylaxis

• Pre-bedtime dosing to maximize dwell time in bladder
• Macrobid tastes worse than bactrim
• Breakthrough UTIs: usually due to noncompliance, incorrect dose, or organism resistance
• Prophylaxis provides little benefit for Grade I/II especially if no BBD
• Recurrence: 15% within 2yrs, and 15% of them will develop renal scarring
• Daily prophylaxis: bactrim 2mg/kg/d (dose per trimethoprim), NFT 1-2mg/kg/d, amoxicillin 12.5-20mg/kg/d, cephalexin 12.5-20mg/kg/d

Endoscopic management

• Materials: PTFE (teflon), PDS (macroplastique), hyaluronate microspheres (deflux)
• Subureteric teflon injection (STING): inject 2-3mm distal to UVJ
• Double hydrodistension implantation technique (HIT): inject x2 within intramural ureter
• Maintain antibiotics x3 months, obtain US at 1mo to rule out new obstruction, obtain US + VCUG at 3mo
• Success: 87% for volcano-shape, only 53% for other shapes, 20% recurrence at 2yrs

Surgical management

• Indications: breakthrough infections despite antibiotics, high grade VUR, evidence renal scarring, lack of renal growth, or antibiotic noncompliance
• Politano-Ledbetter: native hiatus, vertical long submucosal tunnel
• Cohen: ureters directed cross-trigonally via submucosal tunnel (orifice is contralateral to native location)
• Lich-Gregoir: extravesical (bladder not opened), ureter secured within detrusorotomy, 20% risk of voiding difficulty requiring catheter
• VUR resolution 99% for low grade, 94% for high grade
• Majority of low grade VUR detected on 3mo postop VCUG disappears spontaneously
• Immediate postop obstruction usually secondary to inflammation and resolves spontaneously, chronic obstruction uncommon and may be due to ischemia, requiring dilation, stenting, unroofing, or reimplant
• Persistent reflux may be due to high pressure bladder

Randomized Intervention for Vesicoureteral Reflux (RIVUR)

• Compared TMP/SMX with placebo in 607 children with grade I-IV reflux after UTI, 56% toilet trained children had BBD
• Abx prophylaxis decreased febrile/symptomatic UTI risk - 26% vs 37%, RR 0.68
• No difference in renal scarring: 12% vs 10%
• 8 children require abx prophylaxis for 2yrs to prevent 1 febrile UTI
• Greatest risk reduction if BBD, hx febrile UTI, or higher grade VUR

Age Group	IF...	THEN...
< 1yo	Hx febrile UTI + VUR (Grade I-V)	Start abx ppx
	VUR (Grade III-V), no hx febrile UTI	Start abx ppx
	VUR (Grade I-II), no hx febrile UTI	Consider abx ppx
	Male w/ VUR or febrile UTI	Consider circumcision
> 1yo	BBD present	Manage BBD (will make VUR treatment more difficult)
	VUR + BBD and/or febrile UTI	Start abx ppx
	VUR without BBD, febrile UTI, renal anomalies	Consider starting abx ppx
All ages	Breakthrough febrile UTI on abx ppx	Surgical intervention (reimplant vs deflux) vs switching abx
	Worsening renal function, abnormal US, equivocal reflux, breakthrough UTI	Consider DMSA scan
	Non-febrile UTI	Consider abx ppx (can be non-febrile pyelonephritis)
	Asymptomatic on abx ppx	Annual BP, BMP, renal US
	Surgical intervention	Consider renal US +/- VCUG to assess for resolution
	Febrile UTI after surgical intervention	Rule out BBD, obtain VCUG
	Resolved reflux (Grade 0-I)	Discuss stopping abx ppx
	Sibling with VUR	Workup only if renal anomalies or size asymmetry, or hx UTI