Paediatric Nephrology - Acute Kidney Failure

Question 1

What is acute kidney failure defined as?

Answer 1

• Anuria/oliguria <0.5ml/kg/hr for > 8 hours
• Hypertension with fluid overload
• Rapid rise in plasma creatinine
  
  • >1.5x age specific reference, or previous baseline if known

Question 2

AKI - severity

Answer 2

• AKI1
  
  • Measured creatinine >1.5-2x reference
• AK2
  
  • 2-3x reference
• AK3
  
  • >3x reference

Question 3

What are the functions of the kidneys?

Answer 3

• Waste handling
  
  • Urea and creatinine
• Water handling
• Salt balance
• Acid base control
• Endocrine
  
  • Red cells, blood pressure, bone health

Question 4

AKI - management

Answer 4

• Prevention
• 3Ms
  
  • Monitor – paediatric early warning score (BP), urine output, weight
  • Maintain – hydration/electrolytes/acid-base
  • Minimise – drugs
• Address causes
  
  • Pre-renal, renal, post-renal

Question 5

AKI - aetiology

Answer 5

• Pre-renal (perfusion problem)
  
  • Gastroenteritis
  • Haemorrhage
  • Liver disease
  • Renal syndrome
• Renal problem
  
  • Glomeruluar disease
    
    • HUS
    • Glomerulonephritis
  • Tubular injury
    
    • Acute tubular necrosis (ATN) – consequence of hypoperfusion or drugs
  • Interstitial nephritis
    
    • NSAID, autoimmune
• Post-renal
  
  • Obstructive uropathies – stones, tumours, constipation

Question 6

Haemolytic uraemic syndrome - pathology

Answer 6

• Haemolysis
  
  • Packed cell volume <30%
  • Haemoglobin level <10g/dl
• Thrombocytopenia
  
  • Platelet count <150x10⁹/L
• AKI
  
  • Serum creatinine greater than age-related range
  • GFR <80mls/min/1.73m²

Question 7

Haemolytic uraemic syndrome - classification

Answer 7

• Typical
  
  • Post diarrhoea
    
    • Entero-haemorrhagic e-coli (EHEC)
      
      • Such as verotoxin producing E-coli (VTEC) or shiga toxin (STEC)
    • Other causes – pneumococcal infection, drugs
• Atypical HUS

Question 8

Haemolytic uraemic syndrome - presentation

Answer 8

• E-coli 0157:H7 serotype usually
• Bloody diarrhoea (medical emergency)
• Remembered triac of
  
  • Microangiopathic haemolytic anaemia
  • Thrombocytopenia
  • Acute kidney injury/acute renal failure

Question 9

Haemolytic uraemic syndrome - management

Answer 9

• Of bloody diarrhoea
  
  • Prevention of oliguric HUS through intravascular volume expansion
• Of HUS
  
  • 3Ms
    
    • Monitor – fluid balance, electrolytes, acidosis, waste, hormones
    • Maintain – IV normal saline and fluid
    • Minimise – No antibiotics/NSAIDs

Question 10

Haemolytic uraemic syndrome - complications

Answer 10

• Long term consequences
  
  • Blood pressure
  • Proteinuria monitoring
  • Evolution to CKD