Haemo filtering

Description:

Haemo filtering - a method of treatment of patients about HPN based on ultrafiltration of a liquid part of blood with a partial or full recovery of an ultrafiltrate Ringer's solution.

For haemo filtering high-tight haemo dialyzers with the special membranes possessing a hyperpermeability are usually used, transmembrane potential reaches 500 mm of mercury during the procedure.; speed of formation of an ultrafiltrate fluctuates from 70 to 80 ml/min., 18-20 l of liquid are removed and replaced with 4-5 h haemo filtering from an organism.

As at increase in content of crude protein in serum and a hematocrit the size of ultrafiltration decreases, a part of liquid is preferred to be entered before or at the .samy beginning of the procedure.

The clearance of substances at haemo filtering depends on the speed of formation of an ultrafiltrate and a permeability coefficient of a membrane which represents the relation of concentration of this substance in plasma and an ultrafiltrate. Values of coefficient fluctuate from 1 to 0 when substance practically does not pass through a membrane. In the membranes most often used for haemo filtering, a permeability coefficient for vitamin B (a pier. the m of 1200 дальтон) is equal 1, and for inulin - 0,8. Albumine does not pass through a membrane, its permeability coefficient is equal to 0.

During haemo filtering the clearance of urea and inulin equals on average 60 ml/min., the electrolytic composition of plasma practically does not change, except for some increase in content of calcium and reduction of chlorine and phosphorus; in an ultrafiltrate a large number of average molecules is found, and their concentration in serum decrease.

With an ultrafiltrate are lost protein (to 10 g for the procedure), amino acids (6,5 g), some hormones (testosterone, gastrin, parathormone, gastrointestinal peptide, somatomedin B), however level of these hormones in plasma remains invariable, confirming considerable secretory opportunities of glands producing these hormones. The growth hormone, a cortisone and thyritropic hormone in an ultrafiltrate are not found. Thanks to elimination of lipids and the gastrointestinal peptide stimulating insulin secretion at patients the level of lipids in serum is normalized that matters in respect of the prevention of atherosclerosis.

At patients even with a hypertension, refractory to a hemodialysis, within 1 - 7 month of haemo filtering activity of a renin of plasma decreases and the ABP is normalized though extracellular volume significantly does not change. Thus, dehydration during haemo filtering is reached by removal not of extracellular, but intracellular liquid.

At patients with HPN, it is long treated by haemo filtering, the average level of urea, creatinine and uric acid increases in blood in comparison with the treatment period a hemodialysis. Nevertheless 5-year survival of the patients of young age who are on treatment by a hemodialysis and haemo filtering is approximately identical. The main reasons for lethal outcomes, as well as at the patients receiving treatment by a hemodialysis cardiovascular and cerebrovascular complications are. At the same time completeness of rehabilitation at patients to whom it is carried out the haemo filter-tion, above, than at the patients who are on a hemodialysis owing to reduction in a year of days of hospitalization in connection with reduction of episodes of hypotonia.

Haemo filtering - quite expensive procedure as demands a large amount of sterile solutions. Recently methods of regeneration of an ultrafiltrate with its subsequent introduction are offered the patient. It significantly reduces the cost of the procedure.