Nephrotic Syndrome - Overview (Sign and symptoms, pathophysiology)

Summary

This video discusses nephrotic syndrome, focusing on its pathophysiology. It outlines the tetrad of symptoms: proteinuria, hypercholesterolemia, hypoalbuminemia, and peripheral edema. The video explains how damage to the glomerulus leads to protein loss, causing hypoalbuminemia and resulting in hypercholesterolemia. The reduced oncotic pressure contributes to edema, affecting various body areas. The role of the renin-angiotensin-aldosterone system in managing blood pressure is also covered. The video briefly mentions the causes, investigations, and management of nephrotic syndrome, emphasizing renal biopsy as a crucial diagnostic tool.

Takeaways

• 😀 Nephrotic syndrome is characterized by a tetrad of manifestations: proteinuria (>3.5g/24 hours), hypercholesterolemia, hypoalbuminemia, and peripheral edema.
• 😀 The pathophysiology of nephrotic syndrome involves damage to the glomerulus, especially to podocytes, which normally prevent protein loss.
• 😀 Protein loss in nephrotic syndrome results in proteinuria and can lead to immunodeficiency due to the loss of antibodies, increasing infection risk.
• 😀 The loss of albumin in the blood causes hypoalbuminemia, which triggers the liver to produce more proteins and cholesterol, resulting in hypercholesterolemia.
• 😀 Hypoalbuminemia leads to reduced oncotic pressure, causing fluid and electrolyte movement into the interstitium, which results in peripheral edema.
• 😀 A decrease in blood volume due to fluid loss can lead to reduced venous return to the heart, resulting in decreased renal blood flow and GFR.
• 😀 Decreased GFR triggers the renin-angiotensin-aldosterone system, which increases blood pressure and sodium retention, ultimately leading to more edema.
• 😀 The presence of hypercholesterolemia in nephrotic syndrome may lead to xanthelasma (cholesterol deposits around the eyes).
• 😀 Hypoalbuminemia may cause symptoms like tiredness, leukonychia (nail changes), and various types of edema including periorbital, ascites, and lower limb swelling.
• 😀 Investigations for nephrotic syndrome involve urine dipstick tests, blood tests, and imaging (such as ultrasound and chest X-rays) to assess the severity and diagnose the condition.
• 😀 A renal biopsy is critical for diagnosing nephrotic syndrome types, revealing microscopic and architectural changes through light microscopy, immunofluorescence, and electron microscopy.

Q & A

What are the four main manifestations of nephrotic syndrome?

The four main manifestations of nephrotic syndrome are: proteinuria greater than 3.5 grams in 24 hours, hypercholesterolemia, hypoalbuminemia, and peripheral edema.

What causes proteinuria in nephrotic syndrome?

Proteinuria in nephrotic syndrome is caused by inflammation and damage to the glomerulus, particularly to the podocytes, which normally prevent protein loss. This damage allows proteins to pass into the nephron tubule and be excreted in the urine.

What role do podocytes play in nephrotic syndrome?

Podocytes are specialized cells in the glomerulus that normally help prevent protein loss. In nephrotic syndrome, these cells are damaged, allowing proteins such as albumin to pass through the glomerular filtration barrier into the urine.

How does hypoalbuminemia contribute to edema in nephrotic syndrome?

Hypoalbuminemia leads to a reduced plasma oncotic pressure, causing water and electrolytes to move from the circulation into the interstitium, resulting in peripheral edema (swelling), particularly in the feet and lower limbs.

What is the function of the renin-angiotensin-aldosterone system (RAAS) in nephrotic syndrome?

The RAAS is activated in nephrotic syndrome due to decreased blood volume and glomerular filtration rate (GFR). It works to increase blood pressure by retaining sodium and water, which eventually worsens edema due to the already low albumin levels.

What are some signs of hypercholesterolemia in nephrotic syndrome?

A common sign of hypercholesterolemia in nephrotic syndrome is the presence of xanthelasma, which are cholesterol deposits around the eyes.

What are the typical symptoms of hypoalbuminemia in nephrotic syndrome?

Symptoms of hypoalbuminemia in nephrotic syndrome include fatigue and changes in the nails, such as leukonychia striata (white lines or bands in the nails).

Why do patients with nephrotic syndrome sometimes experience shortness of breath?

Shortness of breath in nephrotic syndrome can occur due to fluid overload and edema, particularly if the fluid accumulates in the lungs (pleural effusion).

What types of investigations are commonly used to diagnose nephrotic syndrome?

Common investigations for diagnosing nephrotic syndrome include urine dipstick tests, full blood count, liver function tests, serum and urine immunoglobulins, chest X-rays, ultrasound of the kidneys, and renal biopsy.

What is the role of a renal biopsy in nephrotic syndrome?

A renal biopsy helps to assess the macro and micro changes in the kidneys, particularly in the glomerulus. It can distinguish between different types of nephrotic syndrome and identify specific causes of damage through light microscopy, immunofluorescence, and electron microscopy.