Outline of Dialysis

Dialysis (Hemodialysis), some of the waste in the clinical means blood through a semipermeable membrane to remove. Hemodialysis is a relatively safe, easy, and one of the widely used blood purification techniques. Dialysis is solute through a semipermeable membrane from high concentration solution to the low concentration of the direction of movement. Hemodialysis, including the movement of solute movement and water, blood and dialysate in the dialyzer (artificial kidney) by the contact and the concentration gradient of the semi-permeable membrane material exchange, metabolic wastes and excess electrolyte in the blood to the dialysate move in the dialysate calcium base to move into the bloodstream. If a mixture of albumin and urea into the dialyzer tube soaked in water, when the urea in the dialysis tube will move outside the tube through the artificial kidney membrane pore water, albumin can not pass through the membrane holes. These small molecules through macromolecules can not be semi-permeable membrane material movement phenomenon called dispersion. Clinical diffusion phenomenon to separate the purified blood to make to achieve the purpose of purification method is the basic principle of hemodialysis. Hemodialysis by the use of semi-permeable membrane thickness of 10-20 microns and the average membrane pore size of 3 nm, so only allows the molecular weight of less than 15 000 small molecules and some molecular substances by molecular weight greater than 35,000 large molecular substances can not pass. Therefore, proteins, pyrogens, viruses, bacteria and blood cells are not revealing; the composition of urine is water, we must begin to emit large amounts of water in the blood in order to substitute kidney artificial kidney, artificial kidney only can take advantage of the osmotic pressure and ultrafiltration pressure to achieve the purpose to remove excess moisture. Now used in artificial kidney hemodialysis devices are equipped with these features, in order to regulate the quality and quantity of the blood, so close to the physiological state.