Transcript Antenatal Hydronephrosis

Antenatal Hydronephrosis
Antenatal Hydronephrosis
• Definition:
AP diameter renal pelvis > 4mm @ 20 wk EGA
AP diameter renal pelvis > 7mm @ 30 wk EGA
• Incidence: 5% of pregnancies
Antenatal Hydronephrosis
• Standard work-up:
– Postnatal ultrasound
• Look for
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AP diameter
Calyceal/ureteral dilation
Renal size
Corticomedullary differentiation
Thinned/hyperechoic cortex
Cortical cysts
Ureterocele
Ectopic ureteral insertion
• Best after first 24 hours of life/when not volume depleted
ANH: Work-up (cont.)
– VCUG
• Vesicoureteral reflux
• Posterior urethral valves
• Ureterocele
– Antibiotics (Amoxicillin 10mg/kg/day) until
VCUG done (and normal)
Is a VCUG Necessary?
• Ismaili et al., Journal of Pediatrics, June 2004
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258 pts with ANH
81 w/u WNL
49 uncomplicated duplication or dilation resolved
83 with significant findings
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27 UPJ
23 primary VUR
15 primary megaureter
10 complicated duplication (ureterocele/ectopic ureter)
3 MCDK
2 posterior urethral valves
2 horseshoe kidney
1 renal dysplasia
Ismaili Article Continued
• Normal postnatal US 3% abnormal VCUG
• AP diameter 7-10mm -- 64% had
significant findings
• AP diameter >10mm -- 100% had
significant findings
• Recommends no VCUG if US wnl
• This is in sharp contrast to several earlier
studies
Phan, et al., Pediatric Nephrology,
October 2003
• 68/111 pts with ANH and AP diameter
<10mm (including several wnl)
• 16 (24%) had VUR
Anderson, et al., Pediatric
Nephrology, November 1997
• Postnatal renal sonogram could not
predict presence of VUR in pts with AP
diameter >4mm antenatally
• 9% of pts with nl postnatal US had VUR
Farhat, et al., Journal of Urology,
September 2000
• 27 % of pts with VUR (w/u prompted by
ANH) had a normal postnatal RBUS
Herndon, et al., Journal of Urology,
September 1999
• Of pts later dx’d with VUR (as part of ANH
w/u) 88% had AP diameter <10mm
• 25% had nl postnatal RBUS
• Only 26 ureters (of 112 refluxing units)
dilated on RBUS
Radiology 1993
• 25% of patients with ANH and nl postnatal
RBUS had VUR on VCUG
Breakdown of postnatal dx
• 60%--normal
• 25%--UPJ (includes those that require no
intervention)
• 15%--VUR
• 1-2% other
• (diagnoses may overlap)
When to get an IVP/Mag 3
• More reliable results after 8-12 weeks of
life
• Mag 3 nuclear renogram preferred
• Most algorithms now are based on
delayed T ½ on nuclear renogram and
changes in differential function
Mag 3 Nuclear Renogram with
Lasix Washout
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AP diameter >10mm
After 12 weeks of life
Differential function
Drainage (measured as time to drainage
of ½ volume of renal pelvis from
administration of Lasix [or peak of tracer]),
but the actual image may be more
revealing, depending on region of interest
drawn
When to intervene
• Differential function < 40%
• Progressive decrease in differential
function on sequential nuclear renograms
Onen, Jayanthi, and Koff. Journal
of Urology. September 2002
• Looks at bilateral Initial evaluation: US,
nuclear renogram, serum creatinine
• 13/38 kidneys required pyeloplasty—
criteria: worsening hydronephrosis,
decrease in relative function >10%
• Mean time to maximal improvement by US
post-op 14 months in operated group
• 10 months in nonoperative group
Other Reasons for Intervention
• Symptomatic
– Failure to thrive
– UTI
IVP
• Megaureter
• Persistence of AP diameter >10mm, but
preserved function at one year
DMSA
• Multicystic Dysplastic Kidney
• Assure that there is no function before
abandoning kidney
• 42% of kidneys dx’d as MCDK kidneys
antenatally are actually
hydronephrosis/UPJ obstruction
Conclusions
Most diagnoses made based on a finding of
prenatal hydronephrosis can be handled
conservatively.
However, until we have better ways to
predict who will require intervention, a
complete work-up, including RBUS and
VCUG is warranted in all pts with an AP
renal diameter >4mm prenatally.
Urinary Tract Infections in Children
Incidence
– Neonates: M > F
– Thereafter: F > M
Organisms
• Enterobacteriaciae
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Escherichia (80%)
Klebsiella
Enterobacter
Citrobacter
Proteus
Providencia
Morganella
Serratia
Salmonella
Other Organisms
• Pseudamonas
• Staphylococcus
• Enterobacter
Risk Factors
• Perineal colonization
• Family hx
• Presence of a prepuce
– 10x risk
– Periurethral colonization—circ eliminates this
– Adherence of P fimbriated E. coli to prepuce
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Urethral length
Urine pH (6-7 favors growth)
Urine concentration—dilute has less nutrients
Dysfunctional elimination
Risk Factors—
Dysfunctional Elimination
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Residual urine
Increased intravesical pressure
Bladder overdistension
Constipation
– 24% day wetters
– 34% night wetters
• 90% of pts with UTI and no structural
anomalies had dysfunctional elimination
Not Risk Factors
• Bubble baths
• Improper wiping
Risk Factors
Upper Tract Infections
• Antigen P1 blood group receptors
• Vesicoureteral Reflux
– 25-50% of patients with pyelonephritis have
VUR
– Less virulent strains of E. coli can cause pyelo
inpatients with VUR
• Obstruction
• Heredity
Presentation
• Nonverbal Patient
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Irritability
Poor feeding
Failure to thrive
Vomiting
Diarrhea
Fever
• Verbal Patient
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Urgency
Frequency
Enuresis
Dysuria
Fever
Diagnosis
• Urine Culture is ABSOLUTELY NECESSARY
• Symptoms are not enough
• History is not enough
• Of patients with dysuria, urgency, frequency,
enuresis 18% had + UCX, 40% had URI (yes,
respiratory infection!)
• Local symptoms could be the same with
vulvitis, urethritis, dysfunctional voiding,
dehydration
Urine Cultures
• Bagged specimens are only valuable
when negative
• Voided, midstream catch
• Catheterized best, and necessary in the
pre-potty training age, especially if there is
a fever and the diagnosis of UTI is going
to lead to further testing
Diagnosis
• UA
– WBC 70% reliable
– Bacteria on a centrifuged urine
• UTI if WBC>10/mL & UCx >50k cfu/mL
• Dipstick LE 52.9%, Nitrite 31.4% sensitive
• Nitrites require 4hrs of bacterial incubation
to be +
• LE may give false positive after prolonged
exposure to air
Level of Infection
• Cystitis
– Symptoms
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Dysuria
Frequency
Urgency
2o enuresis
Usually no systemic symptoms
Level of Infection
• Pyelonephritis
– Fever
– Flank pain
– Pyuria
– UCx positive
– Elevated serum WBC, ESR, CRP
Asymptomatic Bacteruria
• Positive urine culture
• No urinary symptoms
• Only 4% later progress to symptomatic
infection
• The organism may be commensal and
protective to prevent infection with a more
virulent organism
• In the absence of VUR, no treatment
necessary, but look for voiding dysfunction
Pyelonephritis (continued
• Diagnosis: UCx and pyuria, but DMSA to
be absolutely certain (in the first several
days of symptoms)
• Risks from episodes of pyelo
– Focal ischemia
– Inflammatory changes
– Renal scarring
– Hypertension
– Renal insufficiency
Treatment
• Lower Tract (no fever)
– Treat 3-5 days
– Start with TMP-SMX, nitrofurantoin or
cephalosporin
– Amoxil may change gut flora and lead to
future infections with resistant organisms
– FQ ok if there is no other oral agent to use
Treatment
• Pyelonephritis
– Treat 10-14 days
– Start with Bactrim of Cephalosporin until
culture is back
– Hospitalization in severe cases
• Abscess
– UCx may be negative
– Parenteral abx x 10 days then 14d oral
therapy
Work-up after a UTI
• Who?
– Fever or documented pyelonephritis
– <5yo
• What
– RBUS (prior to discharge & yes, kidneys &
bladder)
– VCUG once afebrile
– DMSA
• Prophylactic antibiotics until work-up
Prophylaxis
• Vesicoureteral reflux
• No Reflux, but <1yo
– 30-75% recurrence in the first year
• Frequent symptomatic UTIs