Nephrotic Syndrome Flashcards
What is nephrotic syndrome defined as?
A combination of:
- Heavy proteinuria
- Hypoalbuminaemia
- Oedema
- Hyperlipidaemia
What is considered heavy proteinuria?
PCR >200mg/mmol
What is considered hypoalbuminaemia?
Serum albumin <25g/L
What is the peak age of onset of nephrotic syndrome?
<6 years old
How can nephrotic syndrome be classified?
- Primary vs Secondary
- Steroid sensitive vs Steroid dependant vs Steroid resistant
What are type are the majority of cases of nephrotic syndrome?
Steroid sensitive
What features suggest a steroid sensitive nephrotic syndrome?
- Age 1-10 years
- No macroscopic haematuria
- Normal BP
- Normal complement levels
- Normal renal function
When can congenital nephrotic syndrome occur?
In the first 3 months of life
Is congenital nephrotic syndrome common?
No it is rare
Who is congenital nephrotic syndrome more common in in the UK?
Children of consanguineous parents
What is congenital nephrotic syndrome associated with?
High mortality
Why is congenital nephrotic syndrome associated with high mortality?
Due to combinations of hypoalbuminaemia
What happens in nephrotic syndrome?
The glomeruli are affected by inflammation or hyalinisation allowing proteins to pass through cell membranes and appear in the urine
What proteins can be lost in nephrotic syndrome?
- Albumin
- Anti-thrombin
- Immunoglobulins
Why does oedema occur in nephrotic syndrome?
Albumin is the main protein that maintains oncotic pressure preventing leakage of fluid into the extracellular medium, its loss results in oedema
What is the common cause of steroid sensitive nephrotic syndrome?
Minimal change glomerulonephritis
What can cause steroid resistant nephrotic syndrome?
- Focal segmental glomerulosclerosis
- Membranoproliferative glomerulonephritis
- Membranous nephropathy
What are the risk factors for developing nephrotic syndrome?
- Male gender
- Indian subcontinental ethnicity
What is the main non-urinary symptom of nephrotic syndrome?
Breathlessness
What can cause breathlessness in nephrotic syndrome?
Pleural effusion and abdominal distension
What signs can be seen on examination of a child with nephrotic syndrome?
- Periorbital oedema
- Scrotal/vulval/leg/ankle oedema
- Ascites
What blood tests should be performed when investigating nephrotic syndrome?
- FBC
- ESR
- U&E’s
- Creatinine and albumin
- Complement levels (C3 and C4)
What urine tests should be conducted?
- Dipstick for protein
- Urine microscopy and culture
- Urinary sodium concentration
If the patient has recently travelled, what test should be considered?
Malaria screen
What screening tests should be considered?
Hep B and C
What additional tests (not blood, urine or infection) should be considered?
- Antistreptolysin O
- Anti-DNAase B
- Throat swab
- Renal biopsy
When may a renal biopsy be required in nephrotic syndrome?
If atypical or if not responding to steroid treatment
How does steroid sensitive nephrotic syndrome usually appear on light microscopy?
Normal
How does steroid sensitive nephrotic syndrome appear on electron microscopy?
Fusion of podocytes
What are the differentials of nephrotic syndrome?
- Nephritic syndrome
- Cirrhosis
- Severe malnutrition
What is the initial treatment of steroid sensitive nephrotic syndrome?
Oral corticosteroids (60mg/m^2/day prednisolone)
After 4 weeks of 60mg/m^2/day prednisolone how should treatment be adjusted?
Reduce dose to 40mg/m^2 on alternate days for 4 weeks
After 4 weeks of 40mg/m^2 on alternate days how should treatment be adjusted?
Wean or stop
What percentage of cases of nephrotic syndrome will be successfully treated with corticosteroids?
85-90%
Who should be involved if relapses are frequent or a high maintenance dose is required?
Nephrologist
Why should a nephrologist be involved in some cases?
To consider the use of steroid sparing medication
What steroid sparing medications can be used?
- Levamisole
- Alkylating agents
- Calcineurin inhibitors
- Mycophenolate mofetil
- Rituximab
Name an alkylating agent
Cyclophosphamide
Name two calcineurin inhibitors
- Tacrolimus
- Cyclosporin
What is rituximab
Anti-B cell monoclonal antibody
Who should handle the treatment of steroid resistant nephrotic syndrome?
Nephrologist
How is oedema managed in steroid resistant nephrotic syndrome?
- Diuretic therapy
- Salt restriction
- ACE inhibitors
- NSAIDs
What testing can be used to help determine management efficacy in steroid resistant nephrotic syndrome?
Genetic testing
How is congenital nephrotic syndrome often needed to be treated?
Unilateral nephrectomy followed by dialysis until no longer nephrotic and old enough for renal transplant
What are the complications of nephrotic syndrome?
- Hypovolaemia
- Respiratory compromise
- Thrombosis
- Hypercholesterolaemia
When does hypovolaemia usually occur in nephrotic syndrome?
In the initial phase of oedema formation due to fluid shift
What do children with hypovolaemia complain of?
Abdominal pain and faintness
]What are indications of hypovolaemia on testing?
- High packed cell volume of RBCs
- Low urinary sodium
What does a child with hypovolaemia need?
Urgent treatment with IV fluid
Why is urgent treatment with IV fluid required in hypovolaemia?
The child is at risk of vascular thrombosis and shock
What causes respiratory compromise in nephrotic syndrome?
Increasing peripheral oedema
What may be needed if respiratory compromise is severe?
Treatment with IV 20% albumin and furosemide
Why must care be taken when administering 20% albumin?
It can precipitate pulmonary oedema and hypertension from fluid overload
Why must care be taken when administering furosemide?
Can worsen hypovolaemia
What can thrombosis in nephrotic syndrome affect?
- Lungs
- Brain
- Limbs
- Splanchnic circulation
Why is thrombosis a complication of nephrotic syndrome?
The patient can enter a hypercoagulable state
Why do patients with nephrotic syndrome often enter a hypercoagulable state?
- Urinary losses of antithrombin III
- Thrombocytosis
- Increased synthesis of clotting factors
- Increased blood viscosity from raised haematocrit
What can exacerbate thrombocytosis?
Steroid therapy
Why can hypercholesterolaemia occur in nephrotic syndrome?
Cholesterol inversely correlates with serum albumin
