The term "plasmapheresis" comes from the words of the Greek origin "plasma" and "apheresis", which literally can be translated as "to separate the plasma." Plasmapheresis in medicine is the procedure for the extracorporeal cleansing of the blood from toxic and ballast compounds. Membrane, or filtration, plasmapheresis differs from other types of this procedure in the way it is carried out: removal of toxic substances from the blood is carried out by filtering plasma on special devices with plasma filters.
The principle of blood purification by filtration on the device (Hemofeniks, Hemos-PF) is that blood withdrawn from the vessels is separated using special plasma filters into blood cells (erythrocytes, leukocytes, platelets) and plasma. After separation, blood cells return to the patient’s bloodstream, therefore membrane plasmapheresis is called “blood cell laundering”. The filtered plasma is collected in a container and, after the procedure, is disposed of, the lack of circulating blood volume, if necessary, is filled with plasma-substituting solutions.
Plasmapheresis is an auxiliary therapeutic method, which is used in medical treatment only together with the main directions of treatment. The benefit of blood filtering is to detoxify the body, reflex stimulation of the cardiovascular system, increase immunity, improve the rheological properties of blood. Patient reviews of the results of the procedure indicate an improvement in their well-being.
Detoxification of the body
The plasma filter apparatus for membrane plasmapheresis is a semipermeable membrane of porous fiber with a diameter of 10 μm, between which there are pores with a diameter of 5 μm. Such a filter retains blood cells, but freely passes the liquid fraction of blood along with harmful substances dissolved in it (toxic compounds, antigens of microorganisms, pathological immune complexes).
Stimulation of the cardiovascular system
A decrease in circulating blood volume reflexively increases the heart rate, as a result of which the time of one complete circle of blood circulation is reduced. Toxic substances remaining in them are washed out faster from the tissues, which during the next plasmapheresis procedure facilitates their elimination from the body. If a large volume of plasma is removed during the procedure, its deficiency is restored using plasma-substituting solutions.
Passing through the plasma filter, the immune cells come into contact with the substance foreign to the human body. As a result of this contact, the immune system begins to work hard - a state of "tense immunity" arises (as after vaccination). The replacement of a part of plasma by donor plasma substitutes additionally stimulates the patient’s immunity.
Improving blood flow
Improving the fluidity of the blood is not actually from the procedure itself, but from the interstitial fluid in the bloodstream after it. Hemodilution occurs - blood thinning due to protein-free solutions.
If necessary, before the manipulation or during it, patients are administered heparin (70-150 U / kg) of fluid, which helps to improve the rheological properties of blood. In addition, plasma-substituting solutions, introduced after the session to fill the shortage of circulating blood, also dilute it, thereby improving microcirculation in the tissues.
Advantages and disadvantages
The membrane plasmapheresis procedure on modern devices has several advantages over centrifugal and other types of blood purification:
- One of them is the use of a single-needle scheme, which provides patients with comfort during the manipulation;
- the blood purification on the device is continuous, therefore the time of manipulation is reduced in comparison with its other types;
- if sterile disposable circuits (kits) are used for the procedure, this minimizes the risk of the patient becoming infected with hematogenous infections;
- The filtering process is carried out under constant computer monitoring, which guarantees its safety.
However, one should not overestimate the potential of plasmapheresis: it only reduces the concentration of certain harmful compounds in the blood, and does not prevent their formation. Since he does not fight the causes that cause an increase in the concentration of toxic substances, therefore, the method does not "work" independently.
Together with harmful low-molecular compounds (amino acids, electrolytes, acids, alkalis, salts, some enzymes).
In some cases, autoimmune reactions that occur after the procedure are excessive and can provoke an exacerbation of autoimmune processes; therefore, in autoimmune pathologies, control immunological studies should be carried out regularly.
The procedure requires strict indications. The expected benefits of plasmapheresis should significantly exceed the risk of possible complications after it.
Indications for the procedure
The indications for therapeutic filtration plasmapheresis, as recommended by the World Hemapheresis Association, are more than 200 different diseases and pathological conditions. These include:
- exogenous and endogenous intoxications of various etiologies (food poisoning, drug overdose, alcohol, drugs, condition after chemotherapy and radiation therapy, osteomyelitis, severe infections, paraneoplastic intoxication);
- autoimmune, allergic and dermatological diseases (rheumatoid arthritis, multiple sclerosis, scleroderma, lupus erythematosus, bronchial asthma, pollinosis, allergies, dermatomyositis, burn disease, psoriasis);
- pregnancy pathology (Rh-conflicts, gestosis of pregnant women, nephropathy, placental insufficiency);
- respiratory diseases (pneumonia, pneumonitis, hemosiderosis, Wegener's granulomatosis, alveolitis);
- diseases of the digestive system (inflammatory and erosive-ulcerative processes, hepatitis, hepatosis, cirrhosis);
- nephrological diseases (pyelonephritis, glomerulonephritis, renal failure);
- pathologies of the central nervous system and sensory organs (neuroinfection, ophthalmopathy, retinopathy, uveitis);
- diseases of the cardiovascular system (ischemia, angina pectoris, cardiomyopathy, myocarditis, post-infarction conditions, hypercholesterolemia, atherosclerosis);
- endocrine pathologies (diabetes mellitus, Addison's disease, hyperthyroidism);
- blood diseases (monoclonal gammopathy, thrombocytopenic purpura, macroglobulinemia, myeloma).
Once a year, preventive plasmapheresis is recommended for people working in hazardous industries, as well as for people with reduced immunity before the cold season.
Contraindications to plasmapheresis
Despite the fact that membrane plasmapheresis is a useful procedure for many diseases, it still has its contraindications. There are:
- Relative, the elimination of which allows membrane plasmapheresis.
- Absolute, which make the blood purification procedure by filtration on the membranes impossible.
The relative contraindications to performing filtration filtration of blood are:
- high risk of bleeding, for example, with gastric ulcer and duodenal ulcer;
- acute infections;
- menstrual bleeding;
- low blood protein levels;
- severe anemia;
- edema syndrome;
- shock conditions;
Absolute contraindications include reduced blood coagulation, which provokes recurrent bleeding, injuries of internal organs, mental illness, heart and liver failure, arrhythmias, stroke.
Preparation for the procedure
In preparation for the plasmapheresis, the patient is subjected to a whole range of laboratory and instrumental studies, which include: a general and biochemical extensive blood test, a coagulogram, a study on hepatitis B and C, HIV infection, syphilis, blood glucose level, tonometry, electrocardiography. Consultations are also required therapist and cardiologist.
Complete blood count shows the number and ratio of blood cells and the sedimentation rate. The coagulogram determines blood clotting time, tendency to thrombosis or bleeding. The list of biochemical parameters is established depending on the pathology, which is the basis for plasmapheresis, and subsequently monitored after each procedure.
Half an hour before the start of the session, the patient must have a bite to avoid fainting. The day before the procedure it is forbidden to take alcohol, immediately in front of it - to smoke. Also, do not exhaust yourself with heavy physical work or sports loads.
The patient is connected to the device, which, in addition to cleansing the blood, controls the pulse, blood pressure, respiration, and the level of oxygen in the blood.
In most cases, plasmapheresis is well tolerated by patients. Sometimes they notice mild nausea, dizziness, weakness, drowsiness immediately after the procedure.
After the procedure is over, the patient needs rest: for an hour he needs to lie down in a horizontal position so that the volume of circulating blood can be replenished and redistributed in the body. During the entire course of treatment, patients should refrain from visiting the bath, hot baths, stay under the open rays of the sun.
Sensitive people with pronounced side effects (dizziness, severe weakness) can be recommended plasmapheresis in stationary conditions.
The duration of one procedure can be from 60 to 90 minutes. During one session up to 25% of blood plasma can be withdrawn from the patient’s bloodstream. The cost of one session depends on the form of ownership of the clinic and ranges from 3 to 8 thousand rubles. In this case, the city of conducting (Moscow, St. Petersburg or Omsk) usually does not affect the price of manipulation. The number of sessions that are necessary for the patient depends on the disease, which served as an indication for plasmapheresis. For example, 3-5 sessions are prescribed for allergic diseases, 8-10 sessions for severe psoriasis.
Complications after plasma exchange
After the plasmapheresis procedure, some patients may develop various complications. These include allergic reactions, pulmonary edema, bleeding, phlebitis of the veins, to which the system is connected, a drop in blood pressure. Violation of the rules of asepsis and antiseptics during manipulation can lead to infection of patients with viral hepatitis, HIV infection and other infectious diseases with hematogenous transmission.
In one in five thousand patients who have undergone a course of plasmapheresis, the complications are so pronounced that they cause a fatal outcome.
Plasmapheresis is a fairly effective treatment and prophylactic procedure. It allows you to improve the quality of life of long-suffering patients, as well as prevent the development of serious complications in them. However, it is necessary to understand that it is impractical to use it instead of the main treatment of the disease: its effectiveness decreases significantly.