Nephrology 43-46, 55-57 Flashcards
Urinary tract infection pathogens
E. Coli
other gram-negatives (Klebsiella, Proteus, Enterobacter, Citrobacter)
gram-positives
(staphylococcus saprophyticus, enterococcus, staphylococcus aureus)
adenovirus,
fungi
Classification of UTI
depending on level of infection
- Upper urinary tract infection: pyelonephritis
- Lower urinary tract infection: cystitis
- Uncomplicated:
*limited to the lower tract
*age >2
*no underlying medical problems or anatomical malformations
*caused by typical microorganism - Complicated: if any of above is false
risk factors for UTI
- Lack of circumcision
- Boys younger than 1 year, girls older than 4 years
- Female gender (more connected to how bacteria attach to female urethra than its absolute length)
- Urinary obstruction, bladder/bowel dysfunction, vesicles-ureteral reflux, bladder catheterization ◦
Sexual activity
symptoms of UTI children below 2
fever (may be the only symptom),
irritability,
poor feeding,
weight gain
symptoms of UTI children above 2
fever,
dysuria,
urgency,
increased frequency,
incontinence,
hematuria, ◦
abdominal pain,
suprapubic tenderness,
costovertebral angle tenderness
UTI diagnosis
- clinical presentation
- urinary sample (dipstick, culture, microscopic)
- inflammatory marker
- imaging
-US
-voiding cystourethrogram
-renal scintigraphy (DMSA nuclear medicine: renal scarring) - Generally not mandatory during first and uncomplicated UTI
UTI - urine sample diagnosis
- Children who are not potty-trained —> catherization, suprapubic aspiration, (sterile collection bag - not recommended)
- Dipstick
- Urine culture ‣
- Microscopic evaluation ‣
- Bacteriuria: bacteria in urine ‣
- Pyuria: white blood cells in urine (not specific for UTI though, consider appendicitis, GAS
infection, Kawasaki disease
US indication in uti
1ST CHOICE
< 2 years with febrile UTI
recurrent febrile UT
no response to AB
family history of renal or urological disease
Voiding cystourethrogram indication
Best for testing VUR
Indications:
2+ febrile UTIs
abnormalities on US
uncommon pathogen
poor growth
complication of UTI
Upper UTI —>
renal scarring,
hypertension,
end-stage kidney disease
treatment of UTI
- Early antibiotic treatment may prevent renal damage ◦
- Empiric therapy - can be initiated immediately after urine collection with a high probability of UTI
- E. Coli antibiotic choice: 3rd generation cephalosporins (cefuroxime, cefotaxime, ceftriaxone)
50% are resistant against amoxicillin and ampicillin
Increasing resistance toward 1st generation cephalosporins
Aminoglycosides can also be given: gentamicin, amikacin
- E. Coli antibiotic choice UTI
3rd generation cephalosporins (cefuroxime, cefotaxime, ceftriaxone)
50% are resistant against amoxicillin and ampicillin
Aminoglycosides can also be given: gentamicin, amikacin
Considerations in neonates with UTI:
- Blood culture should also be obtained for diagnosis (but relative high risk of an urosepsis)
- US is recommended to identify structural abnormalities
- Empiric treatment: ampicillin + gentamicin 10-14 days, then amoxicillin until radiologic evaluation is done
empiric tratment of neonates with UTI
- Empiric treatment: ampicillin + gentamicin 10-14 days, then amoxicillin until radiologic evaluation is done
Urinary tract malformations incidence
Incidence: 2-3%
Urinary tract malformations are associated with
Associated with other organ anomalies: VATER/VACTERL
* Vertebral anomalies
* Anal atresia
* Cardiovascular anomalies
* Tracheoesophageal fistula,
* Esophageal atresia
* Renal and/or radial anomalies
* Limb defects
Urinary tract malformations suspicion signs
hypospadias
3rd nipple
neck cysts + fistulas
coloboma
aniridia
preauricular fibroma
Kidney malformations
- Renal agenesis
- Renal hypoplasia
- Horseshoe kidney
- Kidney dysplasia
- Multicystic dysplastic kidney
- Ectopic kidney
- Hydronephrosis
- Duplex kidney
Renal agenesis
Kidneys fail to develop
**Bilateral agenesis **
—> part of Potter syndrome, not compatible with life since oligohydramnion
(decreased amniotic fluid)
—> no normal lung development
—> respiratory failure
-
Unilateral agenesis
—> intact kidney is compensating and becomes larger
Renal hypoplasia
- Kidney size and number of nephrons are smaller than average —> reduced performance
- Bilateral hypoplasia
—> hypertension (from increased peripheral resistance)
—> chronic RF - Unilateral hypoplasia
—> asymptomatic, sometimes hypertension
treatment of renal hypoplasia
Treatment:
removal of HTN
+ recurrent pyelonephritis
+ performance < 10%
+ + other kidney is intact
Horseshoe kidney
- Kidneys are connected
- VACTERL-association
- Important to look for:
*males —> gonadal dysgenesis,
females —> Turner syndrome
Treatment not needed but can be associated with hydronephrosis
what can horseshoes kidney be associated with
VACTREL
HYDRONEPHROSIS
Kidney dysplasia
Histological structure shows a significant dysplasia/abnormal structure
- Bilateral dysplasia: decreased renal function, chronic kidney disease
- Unilateral dysplasia: asymptomatic
US finding of kidney dysplasia
Ultrasound findings:
increased echogenicity
cortex and medulla cannot be differentiated,
small cortical cysts
Multicystic dysplastic kidney
- Intact renal parenchyma does not develop, ureter atresia, kidney is completely dysfunctional
- Bilateral: incompatible with life
diagnosis of multicystic dysplastic kidney
intrauterine or neonatal US or physical examination
prognosis of Multicystic dysplastic kidney
- In 40% diseased kidney is absorbed
- In 25% intact kidney undergoes ectopia, hypoplasia, VUR, hydronephrosis
- Rarely malignant transformation (Wilms tumor) —> surgical removal should be considered
Ectopic kidney
- Kidney migration does not occur by the 8th gestational week —> stays in pelvis (may cross)
Bilateral ectopic kidneys: frequent pyelonephritis
Unilateral ectopic kidney: VUR
It’s size and performance is usually smaller than that of healthy kidney
Hydronephrosis
- Dilation of renal cavity
- Most common intrauterine ultrasound abnormality
Etiology hydronephrosis
stenosis of the urinary tract
VUR
ureteral or bladder dysfunction
pathomechanism of hydronephrosis
elevated renal cavity pressure
—> renal pelvis and calyces dilate + renal
parenchyma may also become thinner
prognostic factors for hydronephrosis
renal parenchyma thickness and reflectivity, renal performance
In mild cases —> regress spontaneously in the first months following birth
complication of hydronephrosis
Complication: pyelonephritis
Duplex kidney
- Separate kidney parts have a separate drainage system
- Usually unilateral
*The separate ureters of the pyelonephritis merge —> common entrance to bladder ‣
*The separate ureters of two pyelonephritis do not merge —> separate entrances to bladder (or one has an entrance to other organ like vagina/cervix/vestibule) - Associated with ureterocele
duplex kidney associated with
Associated with ureterocele
symptoms of duplex kidney
usually
* asymptomatic
* dysplasia
* hydronephrosis,
* VUR
* persistent and therapy-resistant UTIs
treatment of duplex kidney
depends on severity, if needed
—> ◦
neoimplantation
heminephrecto-ureterectomia
Cystic kidney diseases
- Monogenic cystic kidney disease
*AR Polycystic kidney disease
*AD polycystic kidney disease - acquired forms (very rare)
Monogenic cystic kidney disease inheritance
More than 70 gene mutations are known
Inheritance:
autosomal recessive OR autosomal dominant
monogenic cystic kidney disease is Responsible for what % of chronic renal failure in childhood
10-20%
Monogenic cystic kidney disease
Progressive disease which spends on the severity of the gene involved and the mutation
—> number and size of cysts increase with age
Autosomal recessive polycystic kidney disease (ARPKD)
Monogenic cystic kidney disease
* PKHD1 gene mutation
- The kidneys are enlarged and the tubule dilation affects the collecting ducts
what is more common ARPKD) or ADPKD
ADPKD
1:400- 1000
US finding of ARPKD
hyperreflectivity, tiny cysts
US finding of ADPKD
kidneys are not hyperreflective
complications of ARPKD
- Severe form of intrauterine oligohydramnios —> pulmonary hypoplasia
—> neonatal respiratory distress - Early HTN
- 50% develop end-stage renal disease by 18 years
- Urinary sepsis
what is ARPKD associated with
liver fibrosis
Autosomal dominant polycystic kidney disease (ADPKD) gene mutation
PKD1 (85%) gene mutation —> more severe form
OR
PKD2 (15%) gene mutation
Autosomal recessive polycystic kidney disease (ARPKD) gene mutation
PKHD1 gene mutation
complications of Autosomal dominant polycystic kidney disease (ADPKD)
Might develop end-stage renal disease by 50-60 years (in PKD1 type)
what is Autosomal dominant polycystic kidney disease (ADPKD) associated with
liver cysts,
berry aneurysms in brain
Ureter developmental disorders
- Pyelouretral junction (PUJ) stenosis (extrinsic VS instrinsic)
- Ureter-vesicular junction (UVJ) stenosis
- Ureterocele
- Vesico-ureteral reflux (VUR)
forms of PUJ stenosis
Forms: intrinsic or extrinsic (vessel strangulation)
◦
Mostly unilateral
diagnosis of PUJ stenosis
- US
(cavity dilation, site of stenosis,
renal parenchyma thickness) - Isotope test of kidney function
complication of PUJ Stenosis
hydronephrosis
treatment of PUJ stenosis
depends on severity,
nephrectomy if needed
treatment of PUJ stenosis
depends on severity,
nephrectomy if needed
Ureter-vesicular junction (UVJ) stenosis diagnosis
- US —> dilated kidney calyces/pyelon/ureter
- Isotope test of kidney function
Ureter-vesicular junction (UVJ) stenosis complications
ureteral dilation,
hydronephrosis