Nephrotic syndrome
Cards (8)
- Nephrotic syndrome:
- Loss of significant volumes of protein via the kidneys which results in hypoalbuminaemia
- Definition = both massive proteinuria (>3.5g/day) and hypoalbuinaemia
- Consequences of hypoalbuminaemia:
- Oedema (reduced oncotic pressure)
- Hyperlipidaemia
- Hypercoagulability
- Symptoms of nephrotic syndrome can include:
- Peripheral oedema (more common in adults)
- Facial oedema (more common in children)
- Frothiness of urine
- Fatigue
- Poor appetite
- Recurrent infections (due to immune dysfunction)
- Venous or arterial thrombosis (e.g. myocardial infarction, deep vein thrombosis) due to hypercoagulability
- Clinical signs of nephrotic syndrome can include:
- Oedema (e.g. peri-orbital, lower limb, ascites)
- Xanthelasma and/or xanthoma
- Leukonychia
- Shortness of breath (with associated chest signs of pleural effusion – e.g. stony dullness in lung bases)
- Typical findings on urinalysis in the context of nephrotic syndrome include:
- Proteinuria (protein ++++)
- Frothy appearance
- Causes:
- Minimal change disease causes over 90% of cases in children under 10
- Most common between ages of 2 and 5
- Can occur in otherwise healthy children without apparent risk factors - no aetiology identified in most cases
- Renal biopsy and standard microscopy in minimal change disease do not detect any kidney abnormalities
- Urine microscopy = oval fat bodies, fatty casts and hyaline casts
- Management:
- High dose steroids for 4-6 weeks
- Low salt diet
- Diuretics
- Albumin infusions
- Antibiotic prophylaxis in severe cases - immune cells lost through kidneys
- Treatment in steroid resistant cases - ACE inhibitors and immunosuppressants
- Complications:
- Hypovolaemia - reduced oncotic pressure due to hypoalbuminaemia leading to fluid to move from the intravascular to interstitial space = low blood pressure, tachycardia and poor tissue perfusion
- Thrombosis - loss of antithrombotic proteins and liver responds to low albumin by producing prothrombotic factors
- Infection - loss of immunoglobulins
- AKI/CKD
- Hyperlipidaemia - impaired clearance of triglycerides and increased production