Urinary Tract Infections

Question 1

What causes UTI?

Answer 1

colonic bacteria
E. coli (54-67%)
Klebsiella and Proteus spp.
Enterococcus and Pseudomonas

Question 2

What are the symptoms of Pyelonephritis?

Answer 2

abdominal pain or flank pain
FEVER, malaise, nausea, vomiting, occ diarrhea

Fever may be the only manifestation
>39C without another source lasting more than 24hrs for males, more than 48hrs for females

Question 3

What are usual locations of renal abscess?

Answer 3

hematogenous spread with S. aureus

most are unilateral and right sided

Question 4

Type of abscess that occur secondary to contiguous infection in perirenal area or pyelonephritis that dissects renal capsule

Answer 4

Perinephric abscess

Question 5

only bladder involvement

Answer 5

Cystitis

Question 6

What are the symptoms of Cystitis?

Answer 6

dysuria, urgency, frequency, suprapubic pain, incontinence, malodorous urine

Does not cause fever and does not result in renal injury

Question 7

Highest risk of acute pyelonephritis and subsequent renal scarring

Answer 7

patients younger than 2yrs

Question 8

What are the risk factors for UTI?

Answer 8

female gender
uncircumcised male
VUR
toilet training
voiding dysfunction
obstructive uropathy
urethral instrumentation
constipation
anatomic abnormality (labial adhesion)
neuropathic bladder
sexual activity
pregancy

Question 9

What are the difference between Type I and II fimbrae?

Answer 9

Type 1: most strains of E.coli, mannose sensitive, no role in pyelonephritis

Type 2: glycosphingolipid, can cause pyelonephritis

Question 10

necessary for confirmation and appropriate therapy

Answer 10

Urine culture

Question 11

How to obtain urine sample?

Answer 11

Toilet trained: midstream urine
uncircumcised males: retract prepuce
Children 2 to 24 months not toilet trained: catheterized or suprapubic aspirate

Question 12

When is the “bag” collection useful?

Answer 12

only if the urinalysis or culture is negative

Question 13

What are usually positive in infected urine specimen?

Answer 13

nitrites and leukocyte esterase

Question 14

high sensitivity and specificity for UTI?

Answer 14

in febrile infants less than 60 days old, with pyuria, nitrites and leukocyte esterase

Question 15

Urine culture findings in patients with UTI?

Answer 15

> 50,000 CFU/ml of a SINGLE pathogen (suprapubic or catheter) with pyuria or bacteriuria in a symptomatic child

Question 16

What is the first line of imaging for screening patients suspected to have UTI?

Answer 16

Ultrasound

Question 17

Treatment for acute cystitis

Answer 17

if mild or diagnosis is doubtful, treatment can be delayed until results of culture are known

If severe, start presumptive treatment

3-5 day course of therapy with TMP-SMX (6-12mg TMP/kg/day in 2 divided doses)
Nitrofurantoin also effective against Klebsiella and Enterobacter.
Amoxicillin can also be used but has high rate of resistance

Question 18

What is treatment for acute febrile UTI?

Answer 18

7-14 days course of antibiotics
For hospitalized, Ceftriaxone (50mg/kg/24hr) or Cefepime (100mg/kg/24hr q12) or Cefotaxime (100-150mg/kg/24hr in 3-4 divided doses)

for outpatient: Cefixime is treatment of choice
Cephalexin may also be considered

Question 19

What is the treatment for acute lobar nephronia?

Answer 19

duration of 14-21 days same antibiotics with pyelonephritis

Question 20

What is the treatment for renal abscess?

Answer 20

larger than 3-5cm: immediate percutaneous drainage
Small less than 3cm: may be treated with antibiotics alone

10-14 days IV antibiotics followed by 2-4wk oral antibiotics

Question 21

What is “bottom up” approach?

Answer 21

renal sonogram plus VCUG to identify upper and lower urinary tract abnormalities including VUR, bladder-bowel dysfunction and bladder abnormalities

Question 22

What is the “top down” approach?

Answer 22

intended to reduce the number of VCUG
begins with DMSA scan to identify acute pyelonephritis

If DMSA is positive then proceed to VCUG

Question 23

AAP recommendation for children 2-24months with first episode of UTI

Answer 23

do initial ultrasound

VCUG if with recurrent febrile UTI, patients younger than 6mos with atypical features (non-Ecoli, sig family history)

Question 24

AAP recommendation for pas with 1st episode of pyelonephritis with normal urinary tract

Answer 24

does not recommend routine use of antibiotics

Question 25

bag sample, urine culture positive, symptomatic or single organism >100,000

Answer 25

presumed UTI