Xiaoli is smart and capable, honest, south to undertake renovation projects for just 3 years, due to good reputation, customers are coming, naturally busy. But in recent months, always feel overwhelmed, tired, busy day, people rush to eat, but he rushed to sleep to go. Family members brought him food, “I’m not hungry!” Then he hung up the sign of exemption from food. The family forced him to go to the doctor, after examination, it turned out that his disease is not light, has developed into chronic renal failure. The doctor recommended that he receive dialysis treatment. Dialysis, what is it? Xiao Li heard this rusty word for the first time and was frozen for a moment, asking the doctor for a simple explanation. Dialysis is a physical phenomenon, that is, the use of a semi-permeable membrane to separate two different components of the liquid, the liquid in the large molecules can not pass through the semi-permeable membrane, so can not be exchanged; liquid in the small molecules can penetrate the semi-permeable membrane and mutual permeability of the law of movement is: water from the low side of the osmotic pressure to the high side of the osmotic pressure; electrolytes and other substances from the high side of the concentration to the low side of the direction of movement After a period of time, the small molecules and water in both sides of the liquid can reach equilibrium, this equilibrium in the principle of physics is the Donan’s equilibrium principle, the principle of equilibrium of this semi-permeable membrane is used in medicine to remove excess water and metabolic waste from the patient’s body, which is the basis of modern blood purification, due to the different methods of operation, divided into peritoneal dialysis and hemodialysis. Peritoneal dialysis is the use of the peritoneum in the human abdominal cavity as a semi-permeable membrane, the area of the peritoneum is like the area of the human body surface, about 2 square meters. The peritoneum is rich in microvessels, and the blood in the vessels is the fluid on one side of the semipermeable membrane. What is the fluid on the other side? The doctor places a silicone tube inside the peritoneal cavity and fills it with sterile water, then there is a solution on the other side of the semi-permeable membrane, and the fluid on both sides immediately begins to exchange substances. As long as the osmotic pressure of the liquid is raised with glucose or amino acids (other body-friendly osmolytes are also available), the water in the blood will go to the peritoneal solution according to the above-mentioned balance principle, and the body wastes such as urea will also leave the blood and move to the peritoneal solution, and the fresh liquid will be replaced repeatedly at regular intervals, so that the body wastes will be removed continuously, and the kidneys will not be able to urinate, and the water will be filtered out by the peritoneal cavity instead. The special intra-abdominal solution is called dialysis fluid. The method is so simple that it can replace the kidneys to continue to maintain life, and live as well without them, and continue to work. The semi-permeable membrane of hemodialysis is not inside the body, but placed inside the dialyzer. The blood is introduced into the dialyzer by puncturing the blood vessels, and the metabolic wastes and excessive electrolytes in the blood are moved into the dialysis solution inside the dialyzer through the semi-permeable membrane, and the dialysis solution is added with substances that are beneficial to the body, such as bicarbonate, which in turn can enter the blood to neutralize the acids and reduce acidosis, which are mutually beneficial. The size of the negative pressure can control the amount and speed of water filtration, replacing the kidney and maintaining the metabolic balance of the body, so it is also called artificial kidney. Some people have statistics, as of December 1993, more than 590,000 people around the world have received dialysis treatment, with the improvement of dialysis equipment and technology, dialysis therapy has developed faster in recent years, China’s dialysis technology is slower than that of developed countries, but the development speed is also fast, although the number of people receiving dialysis is not as good as foreign countries, but the technical level has caught up with the international level.