What is "hemofiltration"? What is the specific definition? What steps are involved and what medical equipment are used to operate?

Hemofiltration technology is to make the blood flow through a filter in the extracorporeal circuit through the machine (pump) or the patient's own blood pressure, and filter out a large number of liquids and solutes under the action of filtration pressure, that is, ultrafiltrate, and at the same time supplement the electrolyte solution, that is, replacement solution, which is similar to plasma liquid composition, so as to achieve the purpose of blood purification.

The whole process simulates the filtration function of glomerulus, but does not imitate the reabsorption and excretion function of renal tubules, but completes some functions of renal tubules by supplementing replacement fluid. Hemofiltration is different from hemodialysis in principle. The former removes solution and part of solute by convection and transmembrane pressure (TMP), and its solute removal rate depends on ultrafiltration volume and sieving coefficient). Thickness of filtration membrane. The latter is to remove solute by dispersion, and its solute clearance rate is proportional to solute equivalent.

Therefore, the clearance rate of small molecular substances by hemodialysis is higher than that by hemofiltration, and the clearance rate of medium molecular substances by hemofiltration is higher than that by hemodialysis.