15.8 Kidney Failure

Question 1

What is kidney failure?
GFR?

Answer 1

Kidney failure is when the kidney cant carry out its normal functions because they wont work properly.
Kidney failure can be detected using the glomerular filtration rate (GFR) - the rate at which blood is filtered from the glomerulus into the Bowman’s capsule

Kidney failure can be caused by many things including kidney infections (inflammation of kidneys, damaging cells) and high blood pressure (capillaries may be damaged so large proteins can get through and be filtered and be in urine)

Question 2

Problems arising from kidney failure

Answer 2

• waste products build up in blood, too much urea can result in weight loss and vomiting
• fluid starts to accumulate in tissues , causes body to swell
• long term kidney failure causes anaemia

Question 3

2 main ways kidney failure can be treated?

Answer 3

• renal dialysis - function of kidneys is carried out artificially
  2 types of dialysis - haemodialysis and peritoneal dialysis
• kidney transplant

Question 4

Describe and explain haemodialysis
Pros and cons?

Answer 4

• blood leaves patients body from artery and flows into dialysis machine, where it flows between partially permeable dialysis membranes (these membranes mimic the basement membrane of the Bowman’s capsule)
• dialysis fluid contains normal plasma levels of glucose to ensure no net movement of glucose out of blood
  Countercurrent exchange system
• dialysis fluid contains no urea, so steep conc gradient
• removes all urea in blood

Pros: 3-4 x a week
Cons: a session can take 4 hours and you cant move around, your diet needs to be restricted, carried out in hospital usually

Question 5

Describe and explain peritoneal dialysis
Pros and cons?

Answer 5

• done inside body - makes use of natural dialysis membranes in lining of abdomen
• done at home
• patient can carry on with their normal life while it takes place
• done until reaches equilibrium so not all urea removed

Pros: done at home, carry on with normal life, diet not as restricted

Cons: multiple times a day, at risk of developing peritonitis (infections)

Question 6

Kidney transplant
Pros and cons

Answer 6

Pros: live a healthy, longer life, dont worry about diet restrictions, no hassle with daily dialysis treatments

Cons: immunosuppressant drugs (immune system can’t work properly to fight off diseases, risk of rejection by body (body cells recognise it as non-self and attack it and destroy it), transplanted organs dont last forever with average kidney lasting 9-10 years, demand is higher than supply