Flashcards in Pediatrics: UTI and Pyelonephritis in Children Deck (85)
Are pediatric UTI common in children?
Who does pediatric UTI affect more often?
Can pediatric UTI occur with normal anatomy?
What 2 situations increase incidence of pediatric UTI?
1. Incidence increases in obstructive conditions: Anatomic or neurogenic (neurodysfunction...cerebral palsy)
What is generally the source of pediatric UTI?
What roles does the urethra play with regard to UTI?
-Mechanical role: The laminar flow of urine washes out bacterial
*Urethral caliber plays little role if any (how wide it is)
What plays a significant role in UTI with regard to the bladder?
-Frequent and complete bladder empyting
What happens in the bladder from infancy into childhood?
There are changes in storage and emptying patterns
How does the bladder work in an infant?
The bladder reflexively empties when filled to its functional capacity
What are the steps of maturation of bladder control?
1. Increase in bladder capacity (holds more urine)
2. Perception of bladder fullness while awake
3. Perception of bladder fullness while asleep
4. Ability to initiate micturition at less than full capacity (2-2.5 years)
5. Inhibition of micturition despite a full bladder
What are some normal bladder defenses against infection?
1. Frequent and complete emptying (stagnant urine collects bacteria)
2. Antibacterial chemical constituents of urine
3. Mucous coating of the uroepithelium (blocks bacteria from attaching)
4. Laminar flow of urine (clears out bacteria)
What does frequent and complete empyting of the bladder result in?
1. Absence of over-distention
2. Maintenance of low pressure in the bladder: Increased pressure results in more strain at the vesicoureteral junction
What are some risks of UTI you must consider?
-Significant residual urine
-High intravesical pressure
-Infrequent bladder emptying
-Retrograde passage of urine (reflux)
-Fistulae from the GI tract
-Foreign bodies in the urinary tract
Why does constipation significantly correlate with UTI?
It is based on increased bacterial contamination
-Mechanical voiding factors
-Relation between infrequent voiding and constipation: Constipation predisposes to bladder instability
What is encopresis?
Inability to control the elimination of stool
-Multiple etiologies...treat underlying cases
What can mimic symptoms of UTI?
Vaginal or urethral irritation
What are some things that can cause vaginal or uretheral irritation?
1. Pinworms: Anal itching
2. Bubble baths
3. Allergens: Sitting in a bubble bath... can hit the mucous membranes
What are environmental influences that can lead to UTI?
-Holding of urine
-Urologic instrumentation or surgery
*General: Anything decrease immune system
What causes 85% of bacterial UTI?
What are other gram-negative bacterial pathogens that can cause UTI?
What are some gram-positive bacterial pathogens that can cause UTI?
What are 2 other categories of agents that can cause UTI?
Viral and fungal
What are some pathogens that can cause UTI due to intstrumentation/catheter?
-Staphylococcus saprophyticus: Coagulase-negative
What can cause UTI in immune compromised patients?
A broad range of organisms
What are clinical features of UTI in neonates?
-Irritability: Can't console
-Failure to gain weight
-Diarrhea: Cross contamination from diaper
What are clinical features of UTI in children?
-Urgency: Going often, nothing coming out
-Enuresis: Bed wetting (from being previously potty-trained
-Fever: No other source
-Failure to toilet train at expected age
What is part of the PE for UTI?
3. Growth paramteres
4. Abdominal exam: Suprapubic tenderness or costovertebral angle tenderness
5. Genitals: Diaper, allergies, ect.
6. Other sources of fever
How must urine sample be collected?
-In a sterile containter: Must be processed within 2 hours
-If refrigerated, processed within 24 hours
Can you give drugs before doing a urine culture?
NO...the drugs with skew the results
How can urine be collected?
1. Clean catch: Sterilize area then pee
2. Maybe cath if no other options
If you have a urine sample collected in a sterile specimine container with borate preservative, how long until it should be processed?
24 hours (no refrigeration needed)
What are the 3 types of tests to be done on urine?
1. U/A dip: In office
2. Urinalysis: Lab
3. Urine C/S
What does a urinalysis look for in UTI?
-If these 3 are present it is probably a UTI...give them an antibiotic
What does a urine C&S look for to diagnose UTI?
Pyuria: WBC (leukesterase on DIP) and bacteruria
How many colonies are seen in a symptomatic child?
If there is positive growth, what do sensitivities typically test for?
3-8 antibiotics and give MIC
What is MIC?
Mean inhibitory concentration
If a drug with a low or high MIC a better choice?
-Lower MIC is desirable
If the child's symptoms are getting worse waiting for culture results, what should be done?
They need to seek care (worry about urosepsis)
If urine is collected suprapubic, what is a positive result?
Greater than 1000CFU/ml
If urine is collected catheter, what is a positive result?
Greater than 50,000/hpf (10^5)
If urine is collected via clean catch, what is a positive result?
Greater than 100,000/hpf (10^5)
What are 3 goals of treatment of UTI?
1. Relief of acute symptoms
2. Eliminate infection and prevent urosepsis
3. Prevent complications
When might hospitalization be needed for UTI treatment?
1. Under 2 months
2. Clinical urosepsis (toxic, hypotension)
4. Emesis/Poor PO intake
5. Outpatient failure
What is important in UTI treatment?
-Early and aggressive therapy...treat empirically after positive urinalysis
What is the most common bug to cause UTI?
E.COLI (but make sure to consider localized resistance)
What is considered in antibiotic selection?
3. Side effects
4. Route of administration
What 2 classes of drugs are good for UTI in pediatrics?
1. Sulfonamides: TMP-SMX- E.Coli sensitivity is good
2. Cephalosporins: Cefixime (Suprax) and Ceftibuten (Cedax) - E.Coli sensitivity is good
What 3 antibiotics are used only if absolutely necessary in pediatric UTI?
1. Aminoglycosides- Gentamicin
3. Quinolones: Ciprofloxacin
What toxicities does aminoglycosides cause?
Oto and renal toxicity, has to be given IV
What toxicities do tetracyclines cause?
What toxicities do quinolones cause?
-Chondrocyte necrosis (cartilage)
-AVOID IN PEDS
For acute uncomplicated UTI what antibiotic regimens should be given for febrile children?
A 10-day course
For acute uncomplicated UTI, what antibiotic course is recommended for competent children without fever?
3-5 day course
What is important to note with prescribing drugs for kids?
You need to do weight dosing relative to kids
When do you use prophylaxis for recurrent UTIs?
In high risk patient population- VUR Grade 3 or higher (Frequent recurrent infections...after 2nd UTI)
What is the antibiotic choice for prophylaxis for recurrent UTIs?
Sulfonamides: One daily dosing of TMP-SMX (Bactrim)
What are 4 steps for the prevention of UTIs?
1. Frequent bladder emptying
2. Frequent diaper changes
3. Surgical correction of anatomical abnormalities
4. Avoidance of irritants (like wipes, ect.)
What are 5 complications seen with pediatric UTI?
1. Focal bacterial nephritis
3. Renal abscess
5. Asymptomatic bacturia
What is cystitis?
Localized bladder infection (lower urinary tract)
What is pyelonephritis?
Infection of the kidney with acute suppurative inflammation of the pelvis, medullary, and cortical tubules, and corticomedullay interstitium (upper urinary tract)
What is urosepsis?
Bacteremia due to pyelonephritis
What is papillary necrosis?
Intense inflammatory response between preserved and necrotic tissue
What is a complication of papillary necrosis that can cause urinary tract obstruction?
Sloughing of necrotic pyramids (some sloughed portions voided and recovered in urine)
What is a perinephric abscess?
Abscess formation in the perinephric space due to extension of bacterial infection across the renal capsule (associated with obstruction of the infected kidney)
What are symptoms of viral cystitis?
Urgency, frequency, incontinence
What are findings in viral cystitis?
Gross hematuria in face of negative culture
What are causative organisms for viral cystitis and when do you see viral cystitis?
-Adenovirus 11 and 21
-Seasonal and epidemic: Spring and fall
What is the treatment for viral cysitis?
What is the goal in evaluation for nonresovling or recurrent UTIs?
Identify the cause: Renal and bladder US, VCUG, DMSA renal scan
When is a renal and bladder US done?
1. Less than age 2 with first febrile UTI
2. Recurrent febrile UTIs
3. Child of any age with UTI who has family history of renal or urological disease, poor growth, or HTN
4. Not responding to other therapy
When is a VCUG performed?
1. Any age with 2+ UTIs
2. First UTI with family history of renal/urological disease
What does a DMSA renal scan evaluate for?
-Pyelonephritis and scarring (seen as photopenia)
-Evaluates the function, size, shape, and position of the kidneys and detects scarring caused by frequent UTIs
How is a DMSA scan performed?
DMSA is injected IV and uptake by the kidney is measured 2-4 hours later....areas of decreased uptake represent pyelonephritis or scarring
What are some downfalls of DMSA scans?
They are expensive, invasice, and expose children to radiation
What is the occurrence of UTI in neonates?
1.4-5 per 1,.000 live births
What is the source of UTI in neonates?
Primarily hematogenous (rather than ascending)
-88% E. Coli
Do more male or female neonates have UTI?
-Males have higher incidence of sepsis
-Higher in uncircumsized males
What happens to the skin and intestines of a newborn?
They are rapidly colonized by bacteria
-Optimally this is from the mother, but ocassionaly nosocomial strains in the delivery unit
What do the aerobic and anaerobic bacteria that colonize the periurethral area do?
They act as a dense barrier against pathogenic microorganisms
Where do bacteria colonize in neonates?
This distal urethra (the proximal area is sterile)
What does breast feeding influence?
The bacterial composition of intenstinal and periurethral flora
What 2 things does human milk contain and what are their effects?
1. Lactoferrin: Antibacterial effect
2. Secretory IgA and complex oligosaccharides: Block adherence of virulent bacterial strains to mucous membranes
What is the source of bacterial in infant UTI?
Urethral: Ascending route