URINARY TRACT INFECTION & VESICOURETERAL REFLUX (UTI & VUR) Flashcards
FEBRILE
UTI
Severe disease ,
complicated with renal
scars, if postponed ,or
incorrect treatment
RENAL SCARS
99m Tc DMSA renal scan/ scintigraphy
ACUTE PYELONEPHRITIS ( PNF)
CLINICAL PRESENTATION
In little child, in newborn, or infant, PNF
appears like a systemic infection→ urosepsis
It is a severe form of nephritis, starting point
being a pyelitis; the inflammatory intrarenal
process involves tubules and renal papilae.
PNF = tubulointerstitial nephritis
It is a debilitating condition , a febrile disease,
which needs often hospitalization
UTI. ETIOLOGY
gram- negative, are predominantly involved
grame-negative bacilli
E.coli, Enterobacter, Citrobacter, Proteus.,
Pseudomonas aeruginosa, Providencia stuartii, Klebsiella,
Morganella morganii, Gardenella vaginalis)
grame – negative cocci
(Neisseria gonorrhea)
grame -positive cocci
Staphylococcus aureus, Staphylococ epiderm., Staf
saprophyte,
Streptococcus D ( fecal,bovis), Streptococcus B ( in
neonates!!).
other pathogens: Chlamidia, Mycoplasma si Candida.
They were also diagnosed viral UTI , both high located,
(pylonephritis) and low located ( cystitis ).
APN PATHOGENESIS
& Markers
E.coli invadates urothelium by fimbriae. Lipopolysaccharides
chelators bind CD14 receptors, cluster of differentiation 14 (human
gene) and activates tool-like receptors (TLR-4).Thus, kB –nuclear
factor (NFkB) migrates inside nucleus of cell and promotes inflamation .
**The markers are: fever , PMN aglutination
and high vascular permeability.
The same mechanism is descibed in renal scars pathology ↑levels of procalcitonine corelates with **renal scars **( argued also by ↑reactive C proteine and high leucocitosis ) it is an
important marker in APN
PYELONEPHRYTIC
NEPHROPATHY
- Delay in initiating
appropriate antibiotic treatment / - The existence of one or more
predisposing risck factors , e.g severe renourinary anomalies lead to -> - definitive renal scarring
- can occur after a single
acute pyelonephritis
UTI – Bacteria contributing factors
Certain types of E. Coli contain P- fimbriae (pili) = surfaces structures of
protein origin which mediates E. Coli attachement to uroepithelial mucosa
prevents proper empting of the bladder
prevents ureteric normaly peristalsis
Hemolysin = cytolytic protein that destroy plasma protein membrane
Siderofores = proteins responsible of iron chelation, prolonging life bacteria.
Contain the capsular polysaccarides which interfere with the alternative
complement pathway
UTI – Bacteria contributing factors
Certain types of E. Coli contain P- fimbriae (pili) = surfaces structures of
protein origin which mediates E. Coli attachement to uroepithelial mucosa
prevents proper empting of the bladder
prevents ureteric normaly peristalsis
Hemolysin = cytolytic protein that destroy plasma protein membrane
Siderofores = proteins responsible of iron chelation, prolonging life bacteria.
Contain the capsular polysaccarides which interfere with the alternative
complement pathway
High / Lower congenital anomalies responsibles of urinary stasis, correlated with UTI
OBSTRUCTIVE CONGENITAL UROPATHYES
ANATOMIC OSTRUCTION
UPPER URINARY TRACT
Pyeloureteral stenosis extrinsic or intrinsic
LOWER URINARY TRACT
Vesicoureteral stenosis
Posterior urethral valves
(Hinman Disease)
Urethral strictures or stenosis
Ureteroceles / Duplications of urinary tract
Ectopic uretheres
Diverticulae bladder
FUNCTIONAL OBSTRUCTION
Vesicoureteral reflux
Neurogenic / Nonurogenic bladder
(Hinman Disease)
UTI– Host contributing factors
- Massive colonization of periurethral /preputial space , in infant boys, 3-6 months of age
- Obstructive anomalies, anatomic or functional
- Neurogenic bladder and bladder disfunction
- Frequent and quantitatively reduced micturation in small hyperactive bladder
- Constipation
- Rare micturations that define “lasy” bladder
UTI- Host contributing factors
Pathophysiology
results from a combination of 3 causes :
- Incomplete empting of the bladder
- Urinary stasis
- High pressure in the uper urinary system.
UTI . LABORATORY
1.Bacterial culture of an appropriately urine sample
2. Suggestive urinalysis exam
In newborn and infants, urine collection is done
in sterile plastic bags attached to perineum (maintained not more than 30 min) or, in the middle of urinary flow in children with urinary continence, after a correct genitourinary toilet
A correct collection of urine could also be carried out, by bladder catheterization, or by suprapubic aspiration
Other tests needed :blood inflammatory tests,
(leucocytosis, ↑procalcitonin,↑C-reactive protein, asotemia, blood gases & electrolytes, etc )
ITU . IMAGING ( imaging targets )
UTI location in acute stage:
99m Tc - DMSA renal scan (scintigraphy), Renal CT and MRI,
are diagnostic investigation, but not rutinely performed
because they are expensive
Underlying obstructive anatomical renourinary anomalies or VUR diagnosis:
US, voiding cystourethrograpy/nuclear cistography, urography, 99m Tc – DTPA or MAG3 renal scan with/without wash out, (diuretic renography) and
renourinary CT
Renal scars quantification :
US and 99m Tc – DMSA ( cortical renography).
ANTIINFLAMATORY TREATMENT IN APN
ANTIBIOTICS
Adecvate use vs restrictive use
Agresiv & Empiric treatment
Personalised treatments
To assess the cost of antibiotic treatment against the entire cost of treatment
Resistence to cefalosporins of : E.coli, enterobacteriacees, proteus, pseudomonas, acinetobacter
Resistence to fluorokinolons of E. coli
! New recommendated AB are β-lactamase inhibitors ( cephalosporins, penicillines, carbapenemes)
ACUTE PYELONEPHRITIS. TREATAMENT. 1
Complicated UTI (acute PNF), in infant, little child and any debilitated clinical situation: really ill pacient, high fever, toxic ill pacient, impossibility to receive liquids orally more than 1,5 normally for age, any child who
needs parenterally administration of fluids, and immunocompromised patients, treatment in hospital is recommended.
We start empirically antibiotic treatment (e.g. aminoglycoside + ampicillin, cephalosporins third gen, or, aminoglycosides + cephalosporins. )
ACUTE PYELONEPHRITIS . TREATMENT. 2
Elder children , with fever but satisfactory general condition , capably to receive orally liquids, if the family can maintain contact with the hospital,
antibiotic treatment could be ambulatory administrated: third gen cephalosporin, 1-2 day/dosis.
Majority of the third gen. cephalosporins are actives on Enterobacter and Pseudomonas aeruginosa species, but not on Enterococcus.
In such situation ampicillin is recommended in association
ACUTE PYELONEPHRITIS.TREATMENT. 3
We maintain parenteraly treatment 3-5 days, until we’ll have uricult results and pacient condition ameliorates.
In such situation the treatment could ongoing, or we can swich from intravenous to oral antibiotic, depend of the bacterial sensibility and
pacient condition
Any febrile UTI (acute PNF) have to be treated by antibiotic for 10- 14days.
ACUTE PYELONEPHRITIS .TREATMENT. 4
Antibiotic Dosis Nr.dosis/day/age
Aminoglicosides
Gentamicin 7,5 mg/kg/day * 3 (> 1week)
Tobramycin 7,5 mg/kg/day* 3 (> 1week)
Penicillins
Ampicillin 50 – 100 mg/kg/day 4
Cefazolin 25 – 50 mg/kg/day* 3 - 4 (> 1
month)
Ticarcillin 50 – 200 mg/kg/day 3 - 4 (> 1
month)
Cephalosporins
Cefotaxime 50 – 180
mg/kg/day*
4 – 6 (> 1
month)
Ceftriaxone 50 – 75 mg/kg/day 1 – 2
Ceftazidime 90 – 150mg/kg/day* 2 – 3 (1month)
UTI. QUINOLONES TREATMENT. 5
In UTI treatment , in Pseudomonas and E. coli , Klebsiella
antibiotic multiresistent infections
Dosis /day in patients between 5 months – 19 years of age ,
9 – 14 mg/kg, diveded in two dosis, follwed by prophylaxis ,
2 – 6 mg/kg/day , 2months – 1year long.
It is also recommended in infections extremely antibiotic
resistent, in severe allergy to antibiotics, or in case of renal function affected by aminoglycosides
In recurrent PNF, infection has been eradicated in 96 – 100% of cases
UTI. QUINOLONES TREATMENT. 6
Repeted surgical procedures (e.g: bladder extrophia , complicate hypospadias etc.) complicated by gram- negative UTI antibiotic resistent, Klebsiella, Enterobacter or Pseudomonas.
Quinolones treatment coud be a good option in UTI antibiotic resistent and lithiasis .
Familly must be informed concerning the posibles adverse reactions to quinolones
UNCOMPLICATED UTI TREATMENT . 1
UTI uncomplicated represents clinical situations
in which , since febrile, the child is in good
condition, is not dehydrated , can take liquids
and medication orally and good familly
cooperation is anticipated
After taking urine culture , one single dosis of
ceftriaxone (50 – 75 mg/kg) is recommended
After that , the treatment can be followed at
home , with one of the indicated orally medication
If evolution is unfavorable in the n**ext 24h
hospitalisation is necessary **. If the child has good
condition, the bacteria sensibility is conforming
with initially medication, the treatment should be
continued at home 7-10 days
In this time delay, laboratory tests and imaging should be done
Drugs recommended in orally treatment in UTI
Medication Daily dosis Nr.dosis
/day/age
Penicillins
Ampicillin 50 –
100mg/kg/day
4
Amoxicillin 20 – 40
mg/kg/day
3
Amoxicillin-
clavulanate)
20 – 40
mg/kg/day
2 - 3
Sulfonamides
Sulfisoxazol 120 – 150
mg/kg/day*
4 (> 2L)
TMP/SMX ** 8 mg/kg/day 2 (>2L)
* Modify function of azotemia
UTI. ORALLY TREATMENT . 2
Drugs Daily dosis Nr.dosis/day/ag
**Cephaolosporins
Cephalexine 20 – 50 mg/kg 4
Cephaclor 20 mg/kg 3 (> 1month)
Cefixime 8 mg/kg* 1- 2
**
(>6months)
Cephadroxil 30 mg/kg* 1 – 2
Cephpodoxime 10 mg/kg* 2 (>6months)
Cephprozil 30 mg/kg* 2 (>6months)
Loracarbef 15 – 30 mg/kg* 2 (>6 months)
Others
Nitrofurantoin 5 – 7 mg/kg 4 (1L)
Acid nalidixic 55 mg/kg 4 (1L)
*Modify function of azotemia
UTI . PROPHYLAXIS . 1
Target of prophylaxis is to prevent bacteriuria.
The ideal prophylactic medication should be :
Active on urinary bacteria
A low rate in developing resistance
None or minimal secondary effects
Have pleasant taste /to have sugar-free drugs
Good toleration , and easy to be taken orally
None effects upon intestinal normal flora
Not expensive
UTI . PROPHYLAXIS. 2
Orally medication in UTI prophylaxis
Drug
Daily dosis ( mg/kg/day) Age (months)
Nitrofurantoin 1 – 2 > 2
Trimethoprim-sulfametoxazol 1 – 2 > 2
Cephalexin 2 – 3 < 2
Amoxicillin 5 <2
Sulfisoxazole 20 – 30 > 2 – 3
Nalidixic acid 12, 5 > 2
VESICOURETERAL REFLUX ( VUR)
VUR DEFINITION
urine retrograde flux from urinary bladder to kidney
PATHOGENESIS
caused by vesicoureteral junction anatomical,
or functional anomalies
VUR :Classification
The International Reflux Study Grading System
classify VUR based by micturating cistography
(VCUG), in** 5 degree (I- V), with progressive
filling of the upper urinary tract, and dilatation
over third (3 ) degree**
Severity of VUR , and medical management are
different a in** low degree VUR (I- III**) versus high
degree VUR (IV - V = dilated VUR)
VUR : frequent pathology
In pediatric nephrology/urology
*Global incidence is estimated at ~ 10% (Sargent, 2000)
- VUR is diagnosed at a rate up 70% in infants suffering of UTI
VUR : PATHOGENESIS
Primary VUR : is a congenital disorder of vesico-ureteral
junction
Secondary VUR : is caused by vesical (anatomical or
functional ) obstruction and, as result of high intravesical
and ureteral pressure
VUR could be associated with:
pyeloureteral junction obstruction, ureterovesical junction
obstruction, ureteral duplications, bladder diverticulae,
horseshoe kidney , or others kidney fusion anomalies, renal
agenesis or multicystic dysplastic kidney
VUR : RENAL IMPACT
VUR low degree often presents spontaneous resolution
(~80% I degree, ~50% III degree ) Arant, 1992
but attention!
** High pressure** and urinary stasis that accompany reflux
and associated UTI ( recurrent PNF) , may cause renal
lesions ( scars, named reflux nephropathy ). In some
severe cases ,
**dilated bilateral reflux kidney **(bilateral urinary
stasis), can lead to **chronic kidney disease **( CKD) and
ESRD
There is a direct relationship between the degree and
severity of reflux, and gravity of reflux nephropathy
VUR : DIAGNOSIS
Attempts to find a noninvasive technique for detecting reflux
are not hundred percent certainly, especially in specifying
the degree of reflux
Since US ( and newer echocontrast cystosonography)
could detects reflux in some cases , a normal US don’t
exclude reflux.
Micturating cistography ( VCUG) is the safest in
detecting reflux in infant with repetitive PNF
VUR : MEDICAL TREATMENT
Prophilaxis after UTI (PNF): low dosis of amoxicillin/
cephalexin/ TMP-SMZ/ nalidixic acid, bedtime administrated
Recurrent UTI : promptly and aggressive antibiotic treatment
**Elder of 5 years age children with bladder urinary
dysfunction **: discipline urination and oxybutynin.
Rehabilitation measures to pattern elimination : adequate
fluid intake, improving hygiene toilet, scheduled urination,
double urination ( morning and evening), constipation
treatment
VUR : FOLLOW-UP
UTI screening, routinely once a month
Ecography/Voiding – Cystography ( VCUG) , once a year
High index of suspicion for UTI in case of febrile
syndrome
Prompt , and aggressive treatment in repetitive UTI
VUR : SURGICAL TREATMENT
Surgical treatment is indicated in selected cases
-
Secondary VUR (due to anatomical obstruction)
or VUR associated with others renourinary abnormalities - VUR associated with deterioration of kidney structure or function ( US and / or renal scans)
- Recurrent UTI under correct prophylaxis
