Nephrotic Syndrome

Nephrotic syndrome is a clinical disorder characterised by oedema, proteinuria, hypoalbuminaemia and hypercholesterolaemia. Minimal change glomerulonephritis accounts for 80 - 85% of nephrotic syndrome in childhood.

Presentation

• Oedema is the primary feature. This may be subtle (peri-orbital region, scrotum or labia) or gross and include in addition, peripheral oedema of the limbs and sacrum. Ascities and pleural effusions may be present when oedema is gross.
• History is often of weight gain, poor urine output and sometimes of discomfort as a result of the oedema. A history of preceding upper respiratory tract infection or diarrhoea may be present.
• Examination should confirm the presence of oedema, assess peripheral perfusion and blood pressure. Examination should include a search for signs suggesting the onset of complications such as infected ascites, renal vein thrombosis (eg enlarged renal mass, loin tenderness and marked heamaturia) and cerebral vein thrombosis.
• Urinalysis should always be included to make the diagnosis as other causes of oedema such as protein losing enteropathy or cardiac failure may occur.
• Infections The altered immune system in patients with nephrotic syndrome is responsible for their enhanced risk of infection. Penicillin during oedematous phases is effective prophylaxis.
• Thrombosis Renal, femoral, cerebral, pulmonary thrombosis may occur in nephrotic patients due to hypovolaemia, high platelet counts and loss of antithrombin III. Thus low dose aspirin is recommended in oedematous nephrotic patients.
• Acute renal impairment This is due to renal hypoperfusion. Albumin is the treatment (see below).

Investigation

1. Urinalysis
   A finding of +++ or ++++ is usual on dipsticks. The degree of proteinuria is variable. Proteinuria is usually of the selective type. Microscopic haematuria is present in 15 - 20% of patients with minimal change nephrotic syndrome. Red blood cells and granular casts may suggest the alternative diagnosis of chronic glomerulonephritis as the underlying cause for nephrotic syndrome.
   
2. Estimating proteinuria
   A timed collection of urine for protein excretion is not necessary when the diagnosis is clear.
   
3. Routine biochemistry
   Urea and electrolytes, creatinine, total protein, albumin, globulin, cholesterol.

Treatment

1. Admit to hospital for first presentation. In the case of relapses consult with treating physician.
2. Intravenous albumin is indicated for anuria, hypotension, poor skin perfusion with skin mottling or poor capillary return. These are all indicators of a depleted vascular space. Give only in consultation with treating consultant. Give 20% albumin 5 ml/kg (1 g/kg) over 4 hr i.v. Beware of the possibility of hypertension and pulmonary oedema. Frusemide should only be given if the peripheral perfusion markedly improves following the albumin or there are signs of pulmonary oedema or hypertension.
3. Gross genital oedema causing discomfort may also be an indication for albumin. Frusemide 1 mg/kg i.v. should be given 2 hr later.
4. Free fluid intake.
5. Diet with no added salt.
6. Oral penicillin 12.5 mg/kg/dose bd (prophylaxis) while oedematous. If the child is profoundly ill or appears to have sepsis use cefotaxime 50 mg/kg/dose 6-hourly to a maximum of 2 g/dose (to cover Strep pneumoniae, H influenzae and E coli).
7. Low dose aspirin (10 mg/kg alternate days).
8. Strict fluid balance.
9. Daily weight.
10. Corticosteroids

Prednisolone

• 60 mg/m2 per day as a single dose up to (max 80 mg/day) for 4 weeks. Then:
• 40 mg/m2 alternate day for 4 weeks.
• 20 mg/m2 per alternate day for 4 weeks.
• 15 mg/m2 per alternate day for 4 weeks.
• 10 mg/m2 per alternate day for 4 weeks.
• 5 mg/ m2 per alternate day for 4 weeks.

Relapses

Over 75% of patients will experience at least one relapse, usually in the setting of an intercurrent illness.

A relapse is defined as proteinuria ++++ or +++ for 4 days. Lower levels of transient proteinuria with fever do not require re-treatment. 

• prednisolone 60 mg/m2 per day till proteinuria dip test result in 0, trace or +. Then:
• 40 mg/m2 alternate day for 2 weeks.
• 20 mg/m2 alternate day for 2 weeks.
• 15 mg/m2 alternate day for 2 weeks.
• 10 mg/m2 alternate day for 2 weeks.
• 5 mg/m2 alternate day for 2 weeks.

If oedema recurs also restart penicillin and aspirin.

Ref:- http://www.rch.org.au/clinicalguide/cpg.cfm?doc_id=5233