kidney failure Flashcards
What is kidney failure? (1)
Occurs when the kidneys cannot carry out their normal functions properly
How can kidney failure be detected? (3)
Can be detected by measuring the glomerular filtration rate (GFR)
Which is the volume of blood filtered by the kidneys over time
A blood test for creatinine levels is used to estimate GFR
What does a high creatinine concentration in the blood indicate? (2)
A high creatinine concentration indicates reduced kidney function due to low GFR
Meaning the kidneys are not working properly
What factors affect GFR measurements? (2)
GFR decreases steadily with age
Men tend to have higher muscle mass than women, which increases creatinine levels
What are the causes of kidney failure? (4)
Kidney infections
Inflammation damages kidney cells, interfering with filtration and reabsorption
High blood pressure
Damages the glomeruli, allowing large molecules like proteins to enter urine
What is the consequence of the accumulation of waste products in kidney failure? (2)
Accumulation of waste products
Like urea leads to symptoms such as weight loss and vomiting
How does fluid retention affect the body during kidney failure? (2)
Fluid retention causes swelling in the legs, face, and abdomen
As the kidneys are unable to remove excess water from the blood
Why does kidney failure lead to high blood pressure? (2)
High blood pressure results from the kidneys’ inability to regulate water balance
Leading to increased pressure in the blood vessels
How does kidney failure affect electrolyte balance? (2)
Loss of electrolyte balance means sodium, potassium, and chloride ions are not excreted properly
Leading to osmotic imbalances and possible death
What causes anaemia in patients with long-term kidney failure? (2)
Kidney failure reduces the production of erythropoietin
Which leads to fewer red blood cells
What is haemodialysis and how does it work? (3)
Haemodialysis is a process where a machine filters a patient’s blood by passing it through a partially permeable membrane
The blood flows in the opposite direction to dialysis fluid (countercurrent flow)
Waste products, excess water, and ions diffuse across the membrane into the dialysis fluid, removing them from the blood
How does the dialysis fluid prevent the loss of useful substances during haemodialysis? (2)
The dialysis fluid contains normal plasma levels of glucose and mineral ions
Preventing glucose loss and ensuring only excess ions move out of the blood
What are the disadvantages of haemodialysis? (2)
Patients can feel unwell between sessions due to waste product buildup
Sessions take 3-5 hours, 2-3 times per week, and usually take place in hospitals, making dialysis expensive and inconvenient
What is the main benefit of haemodialysis over kidney transplants? (1)
Less risky than the major surgery involved in a transplant
How does peritoneal dialysis work? (3)
- Dialysis fluid is introduced into the abdomen using a catheter
- Urea and excess ions pass from the blood capillaries into the tissue fluid and across the peritoneal membrane into the dialysis fluid
- The fluid is drained and discarded
How is the peritoneal membrane different from the artificial dialysis membrane? (2)
The peritoneal membrane can perform active transport and facilitated diffusion
Unlike the artificial dialysis membrane
What is a kidney transplant? (3)
A new kidney is transplanted into a patient to replace a damaged kidney
The kidney must come from a person with a matching blood and tissue type
Either from a living relative or an organ donor
What are the advantages of a kidney transplant over dialysis? (3)
Cheaper in the long term
More convenient for the patient (no regular dialysis)
No periods of feeling unwell between dialysis sessions
What are the disadvantages of kidney transplants? (4)
Major surgery is risky
The immune system may reject the transplant
Requiring lifelong immunosuppressant drugs
Which can reduce the ability to fight infections
Why is it important to closely match the donated kidney to the recipient? (5)
- If not closely matched, the kidney will be recognized as foreign
- The antigens on the donated kidney will differ from those of the recipient
- This causes the immune system to reject the kidney
- Even with close matching, lifelong immunosuppressant drugs are required
- If the recipient is a small child, the donor kidney must be a suitable size
