Dialysis is a separation and purification technology that separates small molecules from biological macromolecules by using the principle that small molecules diffuse into water (or buffer) through semi-permeable membranes. Dialysis therapy is a kind of treatment method to make the components (solute or water) in body fluids excreted through a semi-permeable membrane, which can be generally divided into hemodialysis and peritoneal dialysis.

Dialysis used in medicine can be roughly divided into three categories: hemodialysis, peritoneal dialysis and colon dialysis.

haemodialysis

Hemodialysis, referred to as hemodialysis for short, also known as artificial kidney and kidney washing in popular parlance, is a blood purification technology. It uses the principle of semi-permeable membrane to disperse and remove all kinds of harmful and redundant metabolic wastes and excessive electrolytes in the body, so as to purify blood and correct the balance of water, electrolyte and acid-base.

The thickness of the semipermeable membrane for hemodialysis is 10-20 microns, and the average pore size on the membrane is 3 nanometers, so only small molecules with molecular weight below 15000 and some medium molecular substances can pass through, while macromolecular substances with molecular weight greater than 35000 cannot pass through. Therefore, protein, pyrogen, virus, bacteria and blood cells are impermeable; The composition of urine is mainly water. In order to replace the kidney with an artificial kidney, a large amount of water must be discharged from the blood. Artificial kidney can only use osmotic pressure and ultrafiltration pressure to remove excess water. Nowadays, artificial kidney, that is, hemodialysis device, has these functions to adjust the quality and quantity of blood and make it close to physiological state.

Note: Hemo dialogue is blood, and dialogue comes from Greek, which means releasing some substances.

peritoneal dialysis

Peritoneal dialysis uses the peritoneum as a semi-permeable membrane, and the prepared dialysate is poured into the peritoneal cavity of the patient through a catheter by gravity, so that there is a concentration gradient difference between the two sides of the peritoneum, and the solute on the high concentration side moves (diffuses) to the low concentration side; Water flows from the low permeability side to the high permeability side (osmosis). Through the continuous replacement of peritoneal dialysate, the metabolic products and toxic substances in the body can be eliminated and the imbalance of water and electrolyte can be corrected.

Colon dialysis

Colon dialysis is to inject filtered water into human colon, clean intestinal tract, remove toxins in vivo, fully expand the contact area between colon mucosa and drugs, then inject special liquid medicine to make the liquid medicine absorb various toxins in vivo through colon mucosa and discharge them in time, and finally inject special Chinese medicine preparation and save it. The effective components of drugs are absorbed by colon mucosa, which has therapeutic effect on kidney and can reduce uremia such as reflux and turbidity, serum creatinine, urea nitrogen and uric acid.