renal

Question 1

Q1: A 2-week-old boy presents with a 24 hour history of fever and being unsettled. He is miserable but nil else to find on examination. Urine, blood and cerebrospinal fluid (CSF) samples are collected for bacterial culture.

List three methods of obtaining a urine sample for culture from babies.

Answer 1

1. clean catch
2. catheter specimen
3. suprapubic aspiration

Question 2

Are urine bags suitable for urine culture samples?

Answer 2

no, not sterile, useful for volume measurement

Question 3

CSF is sent for PCR testing for the bacterial meningitis panel (pneumococcus, meningococcus and Haemophilus influenza B) and viral panel (HSV 1&2, VZV and enterovirus). Throat swabs are sent for bacterial culture and for PCR testing for the viral respiratory panel (RSV, influenza A&B, adenovirus).

Urine dipstick is positive for white cells (++), microscopy shows numerous white cells and organisms. Empirical treatment with IV cefotaxime, gentamicin and amoxicillin is started.

After 48hrs the urine culture is positive for Escherichia coli, sensitive to cefotaxime. Renal ultrasound scan shows bladder wall thickening and bilateral renal pelvic dilatation. Micturating cystourethrogram (MCUG) is performed.

What does the MCUG show?

Answer 3

grade 4 vesicoureteric reflux

Question 4

Why is he at increased risk of a urine infection?

Answer 4

• bacteria can replicate rapidly in urine, if it is not regularly cleared from the body bacterial counts can cause a symptomatic infection.
• Vesicoureteric reflux (VUR) facilitates transfer of bacteria from the bladder to the kidneys.

Question 5

What complication may occur if a patient with VUR has a urinary tract infection?

Answer 5

renal damage leading to scarring

Question 6

Urine flow is the most important host defence against a UTI. Children with congenital abnormalities of the kidneys and urinary tract are prone to urine infections. These children often present during infancy with febrile UTI.

What congenital abnormality may have predisposed to bilateral VUR in this male infant?

Answer 6

posterior urethral valves

obstruction at the urethra leads to significant volumes of residual urine in the bladder and in the dilated ureters and renal pelvises

Question 7

what should be be discharged home with?

Answer 7

antibiotic prophylaxis for urinary tract infection with follow-up cystoscopy

Question 8

Q2: A 5 year old boy presents with a one-week history of a puffy face, and swelling of his scrotum and feet. When measured, his weight has increased by 2kg. He had a cough, coryza and febrile illness one week previously.

What do you notice on first inspection?

Answer 8

peri-orbital odema

Question 9

On examination he has scrotal swelling and pitting oedema of his feet and ankles.

What is the most likely diagnosis?

Answer 9

nephrotic syndrome

Question 10

What other investigations would you like to do? Name 4

Answer 10

1. urine dipstick/protein: creatinine ratio, and LFT to check albumin
2. renal function
3. FBC
4. varicella IgG
5. BP
6. urinary sodium

Question 11

What is the most common cause in children?

Answer 11

minimal change disease causes 80-90%

focal segmental glomerulosclerosis causes 10-20% cases of idiopathic nephrotic syndrome

Question 12

What treatment is recommended?

Answer 12

1. prednisolone; 8 weeks starting with 60mg/m² daily for four weeks then reducing doses
2. albumin and furosemide infusions if hypovolaemia or symptomatic oedema
3. prophylactic penicillin owing to increased risk of infections secondary to loss of complement proteins and immunoglobulins
4. referral to dietician for low salt, high protein diet

Question 13

Name two of the possible complications

Answer 13

1. hypovolaemia
2. infection
3. renal vein thrombosis
4. hypertension

Question 14

what is the risk of relapse?

Answer 14

60-70%