Pediatric urinary tract infection Dr. Nariman Fahmi Pediatrics/2013
objectives EPIDEMIOLOGY CAUSATIVE PATHOGENS PATHOGENESIS CATEGORIES OF URINARY TRACT INFECTIONS AND CLINICAL MANIFESTATIONS IN pediatrics DIAGNOSIS TREATMENT
Epidemiology Incidence: Boys: 1% -UTIs are much more common in uncircumcised boys. Girls: 3 5% of girls
Pediatric UTIs 7% of febrile neonates, have UTIs. Causative microorganism E. coli (60-80%) Proteus Klebsiella Enterococcus coag. neg. staph.
The 3 basic forms of UTI are 1-pyelonephritis 2-Cystitis 3-Asymptomatic bacteriuria
Pyelonephritis Clinical Features Pyelonephritis is the most common serious bacterial infection in infants who have (fever without a focus) 1-Newborns may show nonspecific symptoms such as poor feeding, irritability, and weight loss. 2-in children abdominal or flank pain, fever, malaise, nausea, vomiting, and, occasionally, diarrhea.
Cystitis (bladder involvement ) clinical features Dysuria, urgency, frequency, suprapubic pain, incontinence, and malodorous urine. Cystitis does not cause fever and does not result in renal injuries
Asymptomatic bacteriuria positive urine culture without any manifestations of infection. It is most common in girls. The incidence is 1 2% in girls 0.03% in boys.
Risk Factors for Urinary Tract Infection Female gender Uncircumcised male Vesicoureteral reflux Toilet training Voiding dysfunction Obstructive uropathy Urethral instrumentation Wiping from back to front in females
Risk Factors for Urinary Tract Infection Bubble bath? Tight clothing (underwear) Pinworm infestation Constipation Bacteria with P fimbriae Anatomic abnormality (labial adhesion) Neuropathic bladder
General urine exam
Pus cells in urine Microscopical exam
DIAGNOSIS Urine culture proper sample of urine Midstream toilet-trained children catheterized sample Suprapubic aspiration
Definition of UTI on culture Method of urine collection Clean-catch in voiding girls Clean-catch in voiding boys Catheter Suprapubic aspiration Diagnostic threshold 100,000 CFU per ml 10,000 100,000 repeat culture 10,000 CFU per ml 10,000 CFU 1,000 10,000 repeat culture Any colonies of GNRs More than a few thousand GPCs Hillerstein S. Recurrent urinary tract infections in children. Pediatr Infect Dis 1982; 1:275.
Pyelonephritis - leukocytosis, neutrophilia -elevated erythrocyte sedimentation rate and C-reactive protein are common. The latter two are nonspecific markers of bacterial infection
Imaging of the Renal Tract in children The goal of imaging studies in children with a UTI is to identify Anatomic abnormalities that predispose to infection and identify scarring * Renal U/S * KUB * DMSA * Cystogram VCUG/RNC * IVU
Who to image All patients 2 months- 2 years with first UTI Renal U/S, renal Cystogram A typical UTI Recurrent UTI
Plain KUB PROS Cheap Widely available Detects most stones [radio-op] CONS Radiation Poor information
Renal Ultrasound PROS Cheap Quick result No radiation Widely used Good for detecting GU anatomy CONS Not good for detecting VUR Requires cooperation
DMSA renal cortical scan (2-3 months following UTI) PROS Differentiate pyelonephritiss from cystitis -Assess renal scar CONS High radiation Difficult to interpret Require I.V injection
Cystogram Detect identify and grade vesicoureteric reflux
renal image.lnk
Reflux Seen on Voiding Cystourethrogram (VCUG) using transurethral contrast
Grades of VUR
radionuclide VCUG PROS Highly sensitive Very low radiation CONS Still requires catheter
IVU PROS Widely available Demonstrates renal tract and some scarring Calyceal dilatation Filling defect CONS High radiation Allergic reaction Requires i.v. injection Poor visualisation of scars
Treatment of UTI - Aims - Rapid treatment to prevent spread to upper RT and prevent renal scar - Early detection of abnormalities -Arrange appropriate investigation - Prevent recurrence - Correct mechanical obstruction - Appropriate follow up
Antimicrobial Chemotherapy of UTI in children Acute treatment Dose Dosing interval Prophylaxis iv Cefotaxime 100 mg/kg/day 8 hours iv Ampicillin + iv Gentamicin 50-100 mg/kg/day 2 mg/kg/day 6 hours (depends on renal function + plasma conc.) Oral 8 mg/kg/day 12 hours 1-2 mg/kg/nocte Trimethoprim Cephradine 50 mg/kg/day 6-12 hours Nalidixic acid 50 mg/kg/day 6 hours 12.5 mg/kg/nocte Nitrofurantoin 3 mg/kg/day 6 hours 1 mg/kg/nocte Co-amoxiclav 25 mg/kg/day 6 hours
TREATMENT Acute cystitis should be treated promptly to prevent possible progression to pyelonephritis. If the symptoms are severe, a specimen of bladder urine is obtained for culture, and treatment is started immediately. If the symptoms are mild or the diagnosis is doubtful, treatment can be delayed until the results of culture are known
If treatment is initiated before the results of a culture and sensitivities are available, a 3- to 5-day course of therapy with trimethoprim-sulfamethoxazole is effective against most strains of E. coli. Nitrofurantoin (5 7 mg/kg/24 hr in 3 to 4 divided doses) also is effective and has the advantage of being active against Klebsiella-Enterobacter organisms. Amoxicillin (50 mg/kg/24 hr)
Acute febrile infections suggestive of Pyelonephritis A 10- to 14-day course of broad-spectrum antibiotics capable of reaching significant tissue levels is preferable.
When to admit to hospital? Admit when systemically ill child with: -symptoms suggestive of Pyelonephritis -vomiting, dehydration or are unable to drink fluids Young infants (Age 1 mo of age) sepsis
The main consequences of Pyelonephritis chronic renal damage which is presented as -Arterial hypertension and renal insufficiency so Pyelonephritis should be treated appropriately
Atypical UTI Recurrent UTI Some definitions
Atypical UTI includes: seriously ill child( septicemia) poor urine flow abdominal or bladder mass raised creatinine failure to respond to treatment with suitable antibiotics within 48 hours infection with non-e. coli organisms.
Recurrent UTI: two or more episodes of acute Pyelonephritis Or one episode of acute pyelonephritis plus one or more episode of cystitis Or three or more episodes of cystitis
prophylaxis prophylactic antibiotic Used for Patients with vesicoureteric reflux because they have recurrent UTI
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