Hemodialysis

Overview / Hemodialysis

Hemodialysis (Hemodialysis), referred to as hemodialysis, popular saying is also known as artificial kidney, kidney, blood purification technology is a. The use of semi-permeable membrane principle, through the proliferation of the fluid of harmful and excess metabolic waste and excessive electrolyte removed from the body, to purify the blood, correct water and electrolyte and acid-base balance purposes.
According to the different treatment methods, divided into intermittent hemodialysis and continuous hemodialysis treatment. In addition to the application of chronic renal failure replacement therapy, but also widely used in different causes of acute renal failure, multiple organ failure, severe trauma, acute necrotizing pancreatitis, hyperkalemia, hypernatremia, acute alcoholism . To alleviate the symptoms of patients, to extend the survival period have a certain significance, but also emergency treatment, chronic renal failure, one of the effective measures.

principle

Hemodialysis means that the solute moves through a semipermeable membrane from a high concentration solution to a low concentration direction. Hemodialysis, including the movement of solutes and water movement, that is, blood and dialysate in the dialyzer by semi-permeable membrane contact and concentration gradient material exchange, the blood of metabolic waste and excessive electrolyte migration to the dialysis solution, dialysis solution In the calcium ions, bases and other blood to move. If the mixture of albumin and urea into the dialyzer, the tube outside the water soaking, when the dialyzer tube of urea will be moved through the artificial renal membrane hole outside the tube of water, albumin molecules larger, can not pass through the membrane hole. This small molecule can pass through the material can not be through the semipermeable membrane material movement phenomenon known as the dispersion. Clinically with the diffusion phenomenon to separate and purify the blood to purify the purpose of the method is the basic principle of hemodialysis.

Hemodialysis using semi-permeable membrane thickness of 10-20 microns, the membrane pore size of 3 nm on average, it allows only a molecular weight of 15,000 or less small molecules and part of the molecular material through, and molecular weight greater than 35,000 macromolecules Material can not pass. Therefore, protein, pyrogen, viruses, bacteria and blood cells are not visible; most of the composition of urine is water, in order to replace the kidney with artificial kidney must be discharged from the blood of large amounts of water, artificial kidney can only The use of osmotic pressure and ultrafiltration pressure to achieve the purpose of removing excess water. The artificial kidney, or hemodialysis apparatus, which is now used has these functions, so that the quality and quantity of blood can be adjusted to be close to a physiological state.