Nephrotic syndrome

Question 1

Nephrotic syndrome - definition (4)

Answer 1

Combination of:

1. Heavy proteinuria (urinary protein excretion >50mg/kg/d)
2. Hypoalbuminaemia (serum albumin

Question 2

Nephrotic syndrome - background

Answer 2

1. Incidence 2/100,000

2. Peak age of onset in children

Question 3

Nephrotic syndrome - classification

Answer 3

A. Primary (absence of identifiable systemic disease)
*No glomerular inflammation
1. Minimal change disease (MCD)
2. Focal segmental glomerulosclerosis (FSGS)
Note: idiopathic nephrotic syndrome = MCD or FSGS
3. Membranous nephropathy

*Nephritic
4. Mesangiocapillary GN (aka membranoproliferative GN)
5. IgA nephropathy
_____

B. Secondary

• No glomerular inflammation
  1. Some cases of membranous nephropathy
  2. FSGS due to renal scarring/hypoplasia
• Nephritic
  3. Post-infectious GN
  4. SLE
  5. HSP

Question 4

Nephrotic syndrome - clinical presentation + assessment

Answer 4

1. Periorbital edema (esp. on waking) = earliest sign
2. Leg and ankle edema
3. Scrotal or vulval edema
4. Ascites
5. SOB due to pleural effusions and abdominal distension

+ 1. Assess for features not suggesting idiopathic nephrotic syndrome

a. Age 12y
b. Systemic symptoms of fever, rash, joint pains
c. Persistent HTN

+2. Rule out nephritic features (3)

a. Macroscopic haematuria (INS may have microscopic haematuria)
b. HTN
c. Raised serum creatinine (INS may have mild elevation with moderate-to-severe volume depletion

+3. Ax for severity and complications of INS (3)

a. Intravascular volume depletion = dizziness, abdominal cramps, peripheral hypoperfusion
b. Severe/symptomatic edema = potential skin breakdown/cellulitis
c. Infection (increased risk in nephrotic state)

Question 5

Nephrotic syndrome - ix (5+5=10)

Answer 5

Urine (5)

1. Urinalysis = protein +++
2. Urine microscopy - if haematuria/casts, suggests causes other than MCD
3. Urinary sodium - if

Question 6

Nephrotic syndrome - further classification (steroid sensitive or steroid resistant)

Answer 6

Proportion of steroid-resistant nephrotic syndrome:

1. MCD >95%
2. FSGS = 20%
3. MPGN = 55%

Question 7

Nephrotic syndrome - mx

Answer 7

Initial
1. Admit to hospital on first presentation

2. Manage edema (5)
   a. No added salt diet
   b. Daily weighing + daily urine dipstick
   c. Fluid restriction to 800-1000mL/24h
   d. Give albumin if intravascular volume depletion or severe edema (not usually indicated)
   e. Diuretics (frusemide) if giving albumin infusion
3. Prophylaxis against complications
   a. Phenoxymethylpenicillin (oral penicillin V)
   b. Ranitidine (prophylaxis for prednisolone-induced gastritis)
4. Prednisolone to induce remission, followed by slow wean to reduce risk of relapse. Initial dose 60mg/m2/d (max dose 60mg/d) as single dose for 4wks. Consult nephrology if remission not achieved by 4 weeks
5. Family education (3)
   a. Test urine each morning
   b. Document urine protein daily after remission for at least 1-2y. Relapse = 3+ or 4+ protein for 3 consecutive days -> see treating clinician
   c. Most common trigger for relapse = intercurrent infection