Dialysis
Applied Science: BTEC Level 3 National Extended Diploma, topic 4.7.6
Dialysis
Dialysis is one possible treatment for kidney failure. It is an essential treatment for people whose kidneys cannot keep the concentrations of urea and salt at an optimum level to ensure that tissue damage does not occur.
The dialysis machine
- The patient is linked up to the dialysis machine and their blood flows into the machine.
- The machine contains a fluid that is designed to have the optimum concentrations of salts (e.g. sodium and potassium ions) and glucose, as would be found in a healthy person’s blood.
The dialysis fluid
- The patient's blood passes over a partially permeable membrane in the machine that is designed to replicate the kidney tubules.
- The dialysis fluid is on the other side of the membrane. A concentration gradient is established, allowing excess ions and urea to diffuse from an area of high concentration in the patient’s blood to an area of low concentration in the dialysis fluid.
The Advantages and Disadvantages of Dialysis
Dialysis has advantages and disadvantages.
Advantages
- Dialysis is a life-saving process.
- It gives a patient more time to find a donor kidney.
Disadvantages
- Lasts 3-4 hours and is needed 3 times a week.
- Increases risk of blood clots and infections.
- Expensive process.
Test yourself on Dialysis
What diffuses from the patient's blood to the dialysis fluid via a concentration gradient?
Dialysis is one possible treatment for kidney failure. Which of the following are also true of dialysis?
How many times a week must dialysis be performed?