Nephrology

Question 1

Prevalence of UTI in children

Answer 1

2%

Question 2

Laboratory definitions of UTI

Answer 2

> 10^5 organisms/ml on urine culture

Any growth in suprapubic aspirate

Question 3

Why is it important to detect and treat UTI early in children

Answer 3

Pyelonephritis can damage growing kidney and cause permanent scarring
Can lead to chronic renal impairment

Question 4

Clinical features of UTI in infants

Answer 4

Offensive urine 
Fever
Vomiting
Lethargy, irritability 
Poor feeding 
Febrile seizure 
Septicaemia 
—> non specific —> consider UTI in acutely unwell child

Question 5

Methods of urine sample collection in children

Answer 5

Clean catch - sterile pot
Sterile adhesive Bag - higher risk of contamination, not for UTI
In-out urethral catheter - If needed quickly
Suprapubic aspirate

Question 6

Investigations for UTI

Answer 6

Dipstick

Culture

Question 7

Interpretation of Results on dipstick for UTI

Answer 7

Leukocytes & nitrites +ve

If nitrites +ve only - treat if clinical suspicion
If leukocytes +ve only - treat if clinical suspicion

Nitrites are specific for UTI but not sensitive (not all patients w UTI are positive)
Leukocytes are sensitive but not specific (raised in febrile illness w inflammatory response)

Question 8

Common causative organisms for UTI in children

Answer 8

E. coli
Klebsiella
Proteus - in boys with unitary tract obstruction (calculi)
Pseudomonas - If structural abnormality, If indwelling catheter as commensal

Question 9

Causes of UTI in children

Answer 9

Vesicoureteric reflux
Congenital anomalies 
Inadequate fluid intake
Infrequent voiding - play, <6/day 
Incomplete voiding - incorrect toilet sitting and poor relaxation of pelvic muscles 
Constipation

Question 10

Antibiotic treatment for UTI according to age group

Answer 10

<3 months:
Immediate - IV ceftriaxone, cefataxine
Culture sensitive - IV co-amoxiclav 5-7 days

>3 months: 
Depending on culture sensitivity
PO 
trimethoprim (1st line), nitrofurantoin, cefalexine, co-amoxiclav 
3 days if LUTI
7-10 days if UUTI

Question 11

Why do you need to do follow-up investigations in children with UTI

Answer 11

Look for structural abnormalities

Look for renal scarring

Question 12

Who requires further investigations for UTI

Answer 12

All infants <3 months
Recurrent UTI
Atypical UTI: septicaemia, atypical organism, failure to respond to antibiotics

Question 13

First line FU investigation for UTI, what does it detect

Answer 13

Renal USS

Structural abnormalities
Renal defects - dilatation, stones

( Does NOT detect VUR or scarring but still useful)

Question 14

Further investigations for UTI after uss

Answer 14

Micturating cystourethrography

DMSA scan

Question 15

What is MCUG and indication

Answer 15

Filling of bladder with contrast via catheter
Visualise degree of reflux during voiding

<1 year old

Question 16

What is DMSA scan and it’s indication

Answer 16

Injection of DMSA-bound isotope into peripheral vein
Imaging of uptake of isotope by kidneys to detect renal scarring

In >1 year old (less traumatic)

Question 17

Prophylaxis of UTI in children

Answer 17

Treat underlying cause: 
Increase fluid intake
Regular voiding (6-7 times/day) 
Double voiding 
Treat constipation 
Treat vulvitis 
Wipe front to back 

Prophylactic antibiotics: PO trimethoprim nightly

Question 18

Incidence of VUR in children

Answer 18

45% of <5 with UTI

Question 19

Causes of VUR

Answer 19

Familial

Bladder abnormality - neuropathic bladder, urethral obstruction

Question 20

Consequences of VUR

Answer 20

UTI:

• Renal scarring
• CKD
• HTN in childhood/early adulthood

Question 21

Grading of VUR

Answer 21

1: ureter only
2: ureter, pelvis, calices
3: mild dilatation
4: moderate dilatation, tortuous ureter
5: gross dilatation, tortuous ureter, no papillae

Question 22

Investigations for VUR

Answer 22

MCUG

DMSA

Question 23

Management of VUR

Answer 23

Antibiotic prophylaxis
Monitoring - BP, proteinuria, DTPA
Surgery - if scarring progresses despite antibiotics