Nephrology - Nephrotic syndrome Flashcards
How much blood do the kidneys recieve?
25% of cardiac output
How does GFR differ between neonates and children?
- 20-30ml/min/1.73m² in neonate
- 90-120ml/minute/1.73m² by age 2 (same as adults)
What are the five functions of the kidneys?
- Waste handling
- Water handling
- Salt balance
- Acid base control
- Endocrine (RBC/BP/Bone health)
What are the components of the glomerular filtration barrier?
- Endothelial cells
- Glomerular filtration membrane
- Podocytes
- Mesangial cells
What does proteinuria signify?
Glomerular injury
What leans towards nephritic syndrome?
- Increasing haematuria
- Intravascular overload
What leans toward nephrotic syndrome?
- Increasing proteinuria
- Intravascular depletion
Some causes of idiopathic glomerulopathy
- Minimal change disease
- Focal segmental glomerulosclerosis (FSGS)
- Membranoproliferative glomerulonephritis (MPGN)
Some causes of acquired glomerulopathy
- Henoch-Schonlein purpura (HSP)
- IgA
- Lupus
- Post-infectious
Some causes of congenital glomerulopathy
- Alport syndrome
- Thin basement membrane disease
What is the definition of nephrotic syndrome?
Nephrotic range proteinuria with hypoalbuninaemia and oedema
Why does oedema occur in nephrotic syndrome?
- Starling’s forces
- Osmotic vs hydrostatic
- Protein is a magnet to water
- Leakage of protein into 3rd space leads to osmotic forces
How is proteinuria tested for?
- Dipstix
- ≥ 3+ usually abnormal
- Protein Creatinine Ratio (practical)
- Early morning urine is best
- 24hr urine collection (gold standard)
Give the values for normal and nephotic range for protein creatinine ratio
- normal: Pr:CR ratio <20mg/mmol
- nephrotic range: >250mg/mmol
Give the values for normal and nephrotic range for 24 hour urine collection
- Normal <60mg/m²/24hrs
- Nephrotic range>1g/m²/24hrs
- Adults >3.5g/24hrs
How is nephrotic syndrome diagnosed?
- Oedema
- Proteinuria
- Bloods
- Abumin low 12mg/dl (n>32)
- Normal creatinine
What type of nephrotic syndrome is most common in children?
Minimal change disease
Epidemiology of minimal change syndrome
- M:F = 2:1
- Arab countries, India vs Caucasians = 7:1
- Diagnosis by trial of treatment
Typical features of minimal change disease
- Age (2-5yrs)
- Normal blood pressure
- Resolving microscopic haematuria
- Normal renal function
Atypical features of minimal change disease
- Suggestions of autoimmune disease
- Abnormal renal function
- Steroid resistance
If atypical features of minimal change disease are present what investigation should be considered?
Renal biopsy
Treatment for nephrotic syndrome
- If typical features then 8 week course of prednisolone
- Frequent relapses are managed with increased or longer term immune supression
Side effects from glucocorticoids
(Cushing’s syndrome)
- hypertension
- hyperglycaemia
- personality changes
- increased susceptibility to infection (review varicella status and give pneumococcal vaccination)
- growth disturbance
What is the spectrum of idiopathic nephrotic syndrome in childhood?
- Non-relapsing
- Infrequently relapsing
- Frequently relapsing
- Steroid dependent
- Steroid resistant
