Haemodialysis

Question 1

What is haemodialysis?

Answer 1

Filtration of urine artificially other than by the kidneys is defined as haemodialysis.

Question 2

Explain how haemodialysis works

Answer 2

1. One line is connected to an artery of the patient where the blood is collected from the patient for filtration.
2. The blood then enters the dialyzer which contains dialysis fluid and passes through a tube. As blood flows through the tubing, the concentrations of nonprotein plasma solutes tend to reach diffusion equilibrium with those of the solutes in the bath fluid. For example, if the K+ is above normal, it diffuses out of the blood, across the semi-permeable cellophane tubing and into the dialysis fluid. Similarly, waste products and excesses of other substances also diffuse into the dialysis fluid.

Question 3

What is an arteriovenous (AV) fistula?

Answer 3

An abnormal connection between an artery and vein.

The best type of long-term access is an AV fistula. A surgeon connects an artery to a vein, usually in your arm, to create an AV fistula. An artery is a blood vessel that carries blood away from your heart. A vein is a blood vessel that carries blood back toward your heart. When the surgeon connects an artery to a vein, the vein grows wider and thicker, making it easier to place the needles for dialysis. The AV fistula also has a large diameter that allows your blood to flow out and back into your body quickly. The goal is to allow high blood flow so that the largest amount of blood can pass through the dialyzer.