Uraemic toxins

Question 1

What is uremia?

Answer 1

Clinical syndrome that involves a variety of symptoms resulting from kidney failure
It involves the build up of toxins kidneys would normally filter out

Question 2

Symptoms:

Answer 2

GI symptoms
general malaise
tiredness
sleeping during day
neurological issues like confusion and muscle twitching

Question 3

Biochemical basis

Answer 3

Uremia closely linked to build up of urea
Urea is a key thing that is excreted

Question 4

What do uremic toxins contribute to?

Answer 4

Anemia
Accelerated cardiovascular disease caused by calcification of blood vessels
Progresive kidney disease- inflammatory cycle

Question 5

What are the types of uremic toxins?

Answer 5

Small water soluble molecules- e.g urea
Small lipid soluble or protein bound molecules- Phenols
Middle molecules- larger molecules that are harder to filter out by dialysis

Question 6

What is the time course of uremic build up?

Answer 6

Potassiumaccumulates quickly and is fatal quickly
Small nitrogen breakdown products accumulate more slowly and take months or years to be lethal
middle molecules accumulate even longer , prolong damage before lethality

Question 7

Urea

Answer 7

Urea is a helpful marker for dialysis efficiency but is not the main molecule responsible for uremia

Question 8

What are other uremic toxins?

Answer 8

Nitrogenous waste breakdown- tyrosine and tryptophan produced by gut bacteria
Cresyl sulfate and indoxyl sulfate-breakdown products contribute to complications

Question 9

Why are protein bound compounds dangerous?

Answer 9

Cannot be removed by conventional dialysis

Question 10

Why is the accumulation of P-Cresyl sulfate and indoxyl sulfate associated with worsening kidney function

Answer 10

They cause inflammation and damage to
endothelial cells, epithelial cells, leukocytes

Question 11

What does AST 120 do?

Answer 11

Prevent reabsorption of P-Cresyl sulfate and indoxyl sulfate from gut into blood stream
AST 120 ADSORB to the toxins in the gut

Question 12

What else is AST 120 Helpful for?

Answer 12

Improvements in haemoglobin levels
Combined with erythropoietin, may be helpful in improving anemia

Question 13

What are the limitations of dialysis in removing uremic toxins

Answer 13

Cannot remove larger protein bound molecules like P-Cresyl sulfate and indoxyl sulfate causing accumulation

Question 14

How can we solve this?

Answer 14

Inline carbon adsorption device is being explored
shows promising results as it removes toxin not usually cleared by standard dialysis methods