Question

What are the systems that the haemodialysis machine consists of? Name the system and at least one item the system consists of (16)

Dialyzer - Please explain function and list some of its components

Dialysis solution (dialysate) - Please explain function/action and more or less what the solution consists of

Tubing for transport of blood and dialysis solution -Give any special characteristics (size or length) is it single use

Answer 1

The systems of hemodialysis machine are

• Dialysate delivery system
• Extracorporeal blood delivery circuit
• Dialyzer

1) The dialysate delivery system includes the dialysate also known as "bath" made of purified water, bicarbonate and a solution referred to as 'acid' containing minerals and electrolytes.

2) The extracorporeal delivery circuit consists of tubing, blood pump, heparin pump, monitors for blood flow, blood pressure and air bubbles.

3) Dialyzer : It is the key part were cleanising of blood takes place. The dialyzer is a large canister containing thousands of small fibers through which the blood passes. It has an inlet and outlet for blood and dialysate. Blood and dialysate does not come in direct contact. It is separated by a semipermeable membrane. Blood and dialysate flows in opposite direction. This counter currrent flow maintains the concentration gradient and purifies the blood through diffusion, osmosis and ultrafilteration.