Hemodialysis principles

Hemodialysis is a process of purification and filtration of the blood enabling the body to get rid of waste products, excess salts and water from the blood. This is let pass through a tube to a semi-permeable membrane (dialyzer) that filters out waste products and helps the body keep the biogenic ions balance.

The procedure is monitored and controlled by a hemodialysis machine, which provides also the dialysis fluid, mixing it from a concentrate, solids and water. The machine pumps blood, adds anticoagulants, regulates the purification process and controls the mixing of dialysis solution and the rate of its flow through the system. It can also monitor and record the patient's vital characteristics.

Dialysis solution carries away the waste products like urea, creatinine, phosphorus and excess water, and the cleansed blood is returned to the patient through a shunt.

Dialysis is conducted in a dedicated facility, either a special room in a hospital or clinic that specializes in hemodialysis. Nurses and technicians working in the facility have special training dedicated to dialysis. The patient typically receives 2-3 treatments per week, lasting ususally from 4 to 5 hours each. Patients can read, write, sleep, have small talks or follow TV.