UTIs/VU reflux

Question 1

UTI - background (3)

Answer 1

1. Def = bacterial infection involving lower urinary tract (cystitis), upper urinary tract (pyelonephritis) or both
2. Epi: 8% of girls and 2% of boys have had at least one UTI before 7y. Up to half of pts with UTI in childhood have structural abnormality of urinary tract
3. Pyelonephritis may damage the growing kidney by forming a scar, predisposing to HTN and chronic renal failure if the scarring is bilateral

Question 2

UTI - risk factors

Answer 2

1. Anatomic urinary obstruction, e.g. posterior urethral valves
2. Spina bifida (myelomeningocele with neurogenic bladder)
3. VUR = retrograde passage of urine from bladder into upper urinary tract
4. Bladder catherisation
5. Female sex

Question 3

UTI - clinical presentation

Answer 3

Infants 
1. Fever
2. Vomiting
3. Lethargy, irritability, poor feeding, failure to thrive
4. Offensive urine
5. Jaundice, septicaemia
\+/- febrile convulsion (>6mo)

Children

• Lower UTI
  1. Dysuria, frequency, haematuria, offensive/cloudy urine
  2. Mild abdominal pain
  3. Enuresis
• Upper UTI
  4. General = fever (+/- rigors), vomiting, lethargy
  5. Loin pain

+/- febrile convulsion

Question 4

UTI - ex

Answer 4

1. Height and weight - plot on growth chart
2. BP
3. Abdominal masses
4. Genitalia and spine for congenital abnormalities
5. Lower limbs - evidence of neuropathic bladder (impaired neurological function - ?)

Question 5

UTI - dx/ix (5)

Answer 5

1. Try to distinguish between upper and lower urinary tract symptoms. Differentiation is often not possible in the younger child
2. UTI is a major cause of sepsis in a young infant
   __
3. Ask about urinary stream in boys and fhx of vesicoureteric reflux (VUR) or other urinary tract abnormality
   __
4. Dipstick test in urine. Leukocytes + nitrites = strongly suggests UTI
5. Send urine for MCS

Question 6

UTI - mx (1 + 5 + 5)

Answer 6

If 1mo, cystitis:
1. Empirical therapy = trimethoprim + sulfamethoxazole 4+20mg/kg up to 160+800mg orally, 12-hourly
or
2. Trimethoprim 4mg/kg up to 150mg orally, 12-hourly, or
3. Cephalexin 12.5mg/kg up to 500mg orally, 6-hourly
4. Modify empirical therapy based on results of results of cultures and susceptibility testing. Continue tx for 5d in children 1mo, acute pyelonephritis:
1. IV abx for children who (3):
a. Have risk factors for serious illness
b. Are septic
c. Are unable to maintain oral intake/are dehydrated
2. If IV therapy indicated, use gentamicin + benzylpenicillin 6-hourly, see charts for drug doses
____
3. If oral therapy indicated, treat as for cystitis but continue therapy for 7-10d
4. e.g. trimethoprim + sulfamethoxazole 4+20mg/kg up to 160+800mg orally, 12-hourly
5. Modify empirical therapy based on results of results of cultures and susceptibility testing.

Question 7

UTI - imaging following UTI in children (7)

Answer 7

1. Infants aged 6mo, UTI responds well to tx within 48h (1)
   - No further ix needed
2. Children >6mo but 3y, atypical UTI (1):
   - U/S during acute infection
3. Children 3y, recurrent UTI (2):
   - U/S within 6 weeks
   - DMSA 4-6mo after acute infection

DMSA = examination of scars/dysplasia
MCUG = radiological examination of urethra and bladder

Question 8

VUR - background

Answer 8

1. Def = retrograde flow of urine from bladder into upper urinary tract
2. Ureters are placed laterally and enter directly into the bladder rather than at an angle, with a shortened or absent intramural course
3. Usually congenital in origin, but may be acquired (e.g. post-surgery)
4. If combined with UTI, leads to progressive renal scarring; can lead to end-stage renal failure if untreated. Severe cases associated with renal dysplasia
5. Incidence 1% in newborn infants; strong family history (35% incidence rate among siblings of affected children)

Question 9

VUR - management

Answer 9

1. Prevention of symptomatic UTI through prophylaxis (trial for 6mo then review), with selective use of anti-reflux surgery for patients with intractable symptoms

If prophylaxis indicated:

2. Trimethoprim + sulfamethoxazole, 2 + 10mg/kg up to 80 + 400mg orally, at night, or
3. Cephalexin 12.5mg/kg up to 250mg orally, at night, or
4. Nitrofurantoin 1mg/kg up to 50mg orally, at night

If surgery indicated:
5. Subereteric Teflon injection, or re-implantation of ureters through open surgery

Question 10

VUR - prognosis

Answer 10

1. Spontaneous resolution of VUR often occurs, especially with lower grades of reflux
2. 20% will have resolution occurring spontaneously each 3y period
3. Bilateral reflux and reflux into duplex systems is associated with lower probability of resolution