What is haemofiltration?

Hemofiltration is a therapy similar to hemodialysis, which is used to replace the kidney function in the event of kidney failure. Unlike hemodialysis, haemofiltration is almost always used in intensive care environment in cases of acute kidney failure. Therapy works by passing through the patient's blood through a machine that filters out waste products and water, and then adds a replacement fluid before returning the blood into the body. The replacement fluid maintains the volume of fluids in the blood and provides electrolytes. It is usually done daily for as long as necessary. Acute kidney failure can be perverted if treatment begins early enough. Both procedures use semi -permeable membrane to filter blood, but haemofiltration uses a convection together with diffusion, while dialysis uses the diffusion itself. The Convection allows a positive fluid pressure for drive water and soluts through the filter membrane. Diffusion is simply a random movement of particles in the blood, so larger solutes are not filtered as quickly as they are smaller as they move slower.

The convection method solves the problem of its own diffusion, allowing to filter all sizes with similar speeds. The rate of filtration of large and small soluts can be even more balanced by the use of haemofiltration and dialysis in the tandem. This procedure is known as hemodiafiltration.

The spare fluid used in haemofiltration contains either lactate or acetate to generate electrolyte bicarbonate or bicarbonate separately. Lactate can cause problems in some patients such as patients with liver disease or lactate acidosis, a condition in which it causes the accumulation of lactic acid into the bloodstream. Bicarbonate is commonly used for such patients.

haemofiltration and hemodiafiltration can be carried out continuously or intermittently. On-line, intermittent method can be used for outpatient treatment, while the continuous method is usually usedIn intensive care. The intermittent method prepares replacement fluid on-line by filtering dialysis fluid, while the continuous method uses pre-wrapped, sterile and commercially prepared replacement fluid.

intermittent filter therapies are not currently approved by the United States regulators, and heodiafiltration is rarely used in outpatient care in the United States. In Europe, however, this practice is more common, albeit somewhat controversial. Recent studies suggest that interrupted hemodiafiltration may be more effective in therapy than dialysis, but larger studies are required before the problem, including randomized controlled clinical studies.