Nephrotic Syndrome, AKI

Question 1

Clinical features of nephrotic syndrome?

Answer 1

1) Consists of proteinuria (>3.5g/24hrs)
2) Hypoalbuinaemia
3) Oedema
4) Hyperlipidaemia is often seen

Question 2

Aetiology of nephrotic syndrome?

Answer 2

1) Minimal change disease
2) Congenital nephrotic syndrome
3) Secondary to systemic disease (HSP & SLE)

Question 3

Minimal Change disease brief:

Answer 3

• MOST COMMON CAUSE of nephrotic syndrome in children.
• RF/Ax: Idiopathic, drugs: NSAIDs, Lithium, antibiotics - rifampicin, Atopy is present in 30% of cases and allergic reactions can trigger nephrotic syndrome.
• PPx: Glomeruli appear normal in light microscopy - but on electron microscopy there is fusion of the foot processes of the podocytes.
  Cytokine mediated damage to glomerular basement membrane resulting in increased glomerular permeability to serum albumin.

Question 4

Congenital nephrotic syndrome brief:

Answer 4

• Presents in first 3 months and very rare.
• Commonest kind is recessively inherited and more common in Finnish descent.
• Associated with complications of hypoalbuminaemia rather than renal failure.
• Albuminurea so severe that unilateral nephrectomy may be necessary for control followed by dialysis for renal failure.
• Eventually child will need renal transplant

Question 5

Clinical presentation of nephrotic syndrome?

Answer 5

1) Oedema - periorbital, scrotal/vulval, leg and ankle oedema
2) Ascites
3) Breathlessness due to pleural effusion and abdominal distention

Question 6

Diagnosis of nephrotic syndrome?

Answer 6

1) Urine dipstick - proteinurea
2) Blood tests - hypoalbuminaemia
3) Urine MCS

Question 7

Steroid sensitive nephrotic syndrome/minimal change disease RF & Tx?

Answer 7

90% of those with proteinuria can successfully be treated with corticosteroids and hence are steroid sensitive. These children do not progress to renal failure.
Steroid sensitive RF: 
1) Male/asian/atopic
2) Normal BP
3) No macroscopic haematuria
4) Normal renal function
5) 1-10 yrs
6) Precipitated by respiratory infection

Tx:
- Oral Prednisolone
Those who do not respond may require renal biopsy - normal on light microscopy but see fusion of the foot processes of the podocytes on electron microscopy.

Question 8

Complications seen at presentation/relapse in Nephrotic syndrome?

Answer 8

1) Hypovolaemia - oedema causes intravascular compartment to become depleted.
2) Thrombosis - patients are in a hypercoaguable state due to the urinary losses of antithrombin - furthermore the use of steroids will increase synthesis of clotting factors.
3) Infection - those in relapse at risk of infection from encapsulated bacteria such as pneumococcus
4) Hypercholesterolaemia

Question 9

Steroid resistant nephrotic syndrome Ax, RF,Tx?

Answer 9

• DOES NOT RESPOND to steroid treatment
  Ax - 1) Focal segmental glomularsclerosis
  2) Membranous nephropathy

RF:

1) Elevated blood pressure
2) Haematuria
3) Impaired renal function
4) Features suggestive of nephritis

Tx: Management of oedema via diuretics e.g. furosemide, salt restriction and ACE-inhibitors (Captopril).
Sometimes NSAIDs: Ibuprofen may help in proteinuria.

Question 10

AKI PPx?

Answer 10

• Characterised by a rapid rise in serum urea and creatinine or development of oliguria/anuria.
• Due to a rapid decline in GFR leading to failure to maintain fluid, electrolyte and acid-base homeostasis - usually, but not always, reversible.
• Oliguria < 0.5ml/kg per hour

Question 11

Aetiology of AKI (pre-renal)?

Answer 11

• COMMONEST CAUSE IN CHILDREN
• Hypovolaemia - gastroenteritis, burns, sepsis, nephrotic syndrome, haemorrhage
• Circulatory failure leading to ischaemia

Question 12

Aetiology of AKI (renal)?

Answer 12

1) Vascular: Haemolytic uraemic syndrome, Vasculitis
2) Tubular: Acute tubular necrosis (necrosis of renal tubular epithelial cells) due to ischaemia (sepsis/shock) or nephrotoxins (gentamicin, myoglobin).
3) Glomerulonephritis
4) Pyelonephritis

Question 13

Aetiology of AKI (post-renal)?

Answer 13

Obstruction:

1) Congenital - Pelviureteric junction obstruction
2) Acquired - Blocked urinary catheter

Question 14

RF of AKI?

Answer 14

1) Chronic Kidney Disease
2) Organ failure/chronic disease - Heart failure, liver disease, DM
3) Nephrotoxic drugs - NSAIDs, Ace-inhibitors, diuretics within past week

Question 15

Clinical presentation of AKI? Ddx?

Answer 15

1) Often depends on causes and sometime no symptoms
2) Oliguria
3) Pulmonary and peripheral oedema
4) Arrhythmias - due to changes in potassium and acid-base balance
5) Features of uraemia (pericarditis/encephalopathy)

Ddx: Chronic kidney disease, drug side effects

Question 16

Diagnosis of AKI?

Answer 16

1) U & E’s: Raised K+, creatinine, urea, phosphate
Low: Ca2+, Na+, Cl-
2) Urinalysis
3) Urine dipstick
4) Ultrasound - check for obstruction + renal parenchyma (small kidneys or large bright kidneys)

Question 17

Treatment of AKI?

Answer 17

Correct metabolic abnormalities:

1) Metabolic acidosis (with sodium bicarbonate)
2) Hyperphosphataemia (calcium carbonate as it binds phosphate) + dietary restriction
3) Hyperkalaemia (Calcium gluconate (if ECG changes), Salbutamol (nebulised/IV), glucose and insulin).

Pre-renal: Suggestive of hypovolaemia hence needs fluid replacement and circulatory support (blood transfusion)

Renal: Treat underlying condition, and treat circulatory overload - restrict fluid intake and use diuretic (furosemide)
- May help increase urine output sufficiently to allow gradual correction of Na+ and water balance.

Post-renal: Requires assessment of the site of obstruction and relief by nephrostomy or bladder catheterisation.
Surgery can be performed once fluid volume and electrolyte abnormalities have been corrected.

DIALYSIS when indicated.

Question 18

When is dialysis indicated?

Answer 18

1) Failure of conservative management
2) Hyperkalaemia
3) Hypo or Hypernatraemia (severe)
4) Pulmonary oedema/hypertension
5) Severe acidosis
Peritoneal dialysis or haemodialysis can be undertaken.