Erythrocyte mass

The erythrocyte mass (EM) is a component of blood, which consists of erythrocytes (70-80%) and plasma (20-30%) with an admixture of white blood cells and platelets (hematocrit - 65-80%). According to the erythrocyte content, a single dose of erythrocyte mass (270 ± 20 ml) is equivalent to one dose (510 ml) of blood.

There are 6 types of erythrocytic mass (erythrocyte mass, filtered, erythrocyte mass, gamma-irradiated, erythrocytic mass depleted of leukocytes and platelets, erythrocyte mass with removed leukotrombolome, erythrocyte mass with removed leukotrombolome, filtered, erythrocyte mass with removed leukotrombolome, gamma-irradiated) and several kinds of auto-erythrocyte mass (auto-EM, auto-EM, filtered, auto-EM, gamma-irradiated, etc.).

Erythrocyte Suspension (EB) is an erythrocyte mass resuspended in a special solution of sodium chloride and a hemoconservant containing gelatin preparations and some other components. As a rule, the ratio of erythrocyte suspension and solution is 1: 1. Erythrocyte suspension, acquiring higher fluidity and correspondingly higher rheological properties, simultaneously has a lower hematocrit (40-50%).

There are 5 types of erythrocyte suspension (erythrocyte suspension with physiological solution, erythrocyte suspension with resuspension solution, erythrocyte suspension with resuspension solution, filtered, erythrocyte suspension with resuspension solution, gamma-irradiated, erythrocyte suspension, thawed and washed).

Erythrocyte mass depleted of leukocytes and platelets (washed erythrocytes - (OE) is an erythrocyte mass lacking plasma as well as leukocytes and platelets by 1-5 times repeated addition of physiological solution and removal of the supernatant after centrifugation .The washed red blood cells are stored until use in a suspension of 100-150 ml of physiological solution with hematocrit 0,7-0,8 (70-80%).

To remove leukocytes from whole canned blood or erythrocytic mass, special filters are actively used that allow to remove more than 99% of white blood cells, which allows to reduce the number of post-transfusion reactions of nonhemolytic type and, thus, to increase the effect of therapeutic procedures.

Erythrocyte suspension, thawed and washed, - the method of freezing and storing erythrocytes at low temperatures (up to 10 years) allows you to get functionally full red blood cells after defrosting and washing from the cryoprotector (glycerol). In the frozen state, red blood cells can be up to 10 years.

As with donor blood, it is more advisable, from both a medical and an economic point of view, to harvest autologous (autogenous) hemocomponents instead of whole canned autografts: erythrocyte mass, freshly frozen plasma (FFP), in some cases, thromboconcentrate. With adequate medical preparation of the patient (iron preparations, vitamin therapy, erythropoietin) 2-3 weeks before the operation, it is possible to prepare from 600-700 to 1500-18 000 ml autosilicates, 400-500 ml of autoimmunoassay.

In some cases autoEV is obtained from autoEM with a physiological solution or with additional filtration - autoEV with a resuspension solution, filtered.

[1], [2], [3], [4]

Erythrocyte mass: a place in therapy

Erythrocyte mass is prescribed for the purpose of arresting anemia to enhance the oxygenating function of the blood. In contrast to canned blood, the use of EM significantly reduces the likelihood of immunization of a patient with plasma proteins, leukocytes and platelets of donor blood.

In patients with normal baseline parameters of hemoglobin, hematocrit and plasma proteins with blood loss within 10-15% of BCC, it is not necessary to use EM. Maintain stable hemodynamics and compensate for blood loss with blood substitutes.

With blood loss more than 15-20% of bcc, as a rule, the first signs of a violation of the oxygen transport function of the blood are observed, which requires adequate replenishment of the erythrocyte deficiency, i.e. Application of EM. Transfusions EM, EV can be produced by drip or jet.

Establish any absolute laboratory criteria for the appointment of EM is not possible and is hardly advisable. First of all, it is necessary to take into account the clinical condition of the patient, the concomitant pathology, the degree and location of the injury, the cause of anemia, bleeding time and many other factors. Thus, it is known that patients with chronic anemia are more adapted to a low level of hemoglobin. At the same time, patients with arterial hypotension, with severe cardiopulmonary insufficiency, with infectious diseases, etc. Require EM transfusion even at higher values of red blood indices.

With chronic blood loss or hemopoietic insufficiency, the basis for the infusion of red blood cells in most cases is a drop in hemoglobin level below 80 g / l and a hematocrit below 25% (0.25 l / l). To improve the rheological properties of EM (or EC) just before transfusion, it is possible to add a 0.9-1% solution of sodium chloride to the container, which actually converts it into EV with physiological saline. Indications for transfusion of EV, OE, thawed OE are similar to the erythrocytic mass assignments:

• traumatic and operational shock, complicated by blood loss;
• anemic hypoxia in normo-hypovolemic states;
• posthemorrhagic anemia;
• in the period of preparation of patients with critically low indices of the hemogram to extensive surgical interventions;
• posttermic (with burn disease) anemia.

Washed erythrocyte mass is used in patients sensitized by previous blood transfusions to plasma factors or antigens of leukocytes and platelets. The cause of most nonhemolytic transfusion reactions in patients who had a history of multiple transfusions of blood components, as well as women who had a pregnancy, are iso-antibodies to leukocyte antigens (in particular, HLA), which undoubtedly reduce the effect of not only the transfused component, but also the entire treatment procedure. Washing the erythrocyte mass almost completely eliminates plasma and elements of destroyed cells of peripheral blood, platelets and dramatically reduces the white blood cell count (<5 x 109).

Indications for the use of washed red blood cells:

• anemia of various etiologies, accompanied by sensitization of the recipient to antigens of plasma proteins, leukocytes and platelets as a result of repeated blood transfusions or pregnancy;
• homologous blood syndrome (as an element of complex therapy);
• compensation of blood loss in allergic patients (bronchial asthma, etc.) in order to prevent anaphylactic reactions.

Transfusions of auto-EM in the intra- and post-operative period in order to correct anemia are carried out in the presence of indications.

For immunocompromised patients, it is recommended to use auto-EM, gamma-irradiated, or auto-EB with a resuspension solution, gamma-irradiated.

[5], [6], [7], [8], [9],

Physiological properties of erythrocyte mass

The components of autoblood are parts of the patient's own blood, which determines their physiological properties-providing the tissues and cells of the body with oxygen and delivering carbon dioxide into the lungs. After 8-10 days of storage in the erythrocyte mass, a slight hemolysis may be detected, which is not a contraindication for its clinical use. The longer the shelf life, the lower the oxygen transport function of red blood cells. In erythrocyte components is less than whole blood, a preservative, in the MA it is completely absent. The washed erythrocyte mass contains a trace amount of protein components of plasma, platelets and leukocytes.

Pharmacokinetics

Components containing donor erythrocytes after blood transfusion in the body function from several days to several weeks, which is largely determined by the timing of the preparation of erythrocytes, the type of preservative and the conditions of their storage (native, thawed, washed). In the body, the destroyed donor red blood cells are utilized by the cells of the reticuloendothelial system of the parenchymal organs.

Contraindications

Contraindications to the use of EM and EV: massive hemorrhage (more than 40% BCC), hypocoagulation conditions, thromboembolism of various genesis, acquired non-hemolytic anemia.

Hemolysis of autoblood or autoimm (EV) (free hemoglobin> 200 mg%) is a contraindication for blood transfusion. Such erythrocytic mass before blood transfusion is washed.

[10], [11], [12], [13], [14], [15], [16],

Tolerance and side effects

If the rules of preparation, processing, storage and adequate application of donor erythrocytes are observed, the risk of reactions and complications is minimized.

Warming blood components reduces the risk of hypothermia with massive transfusions of chilled blood components. The minimum recommended temperature for transfused blood and its components is + 35 ° C. When transfusion of unheated blood or its components, ventricular arrhythmias can sometimes be observed (usually do not develop until the body temperature drops below + 28 ° C).

Distinguish pyrogenic, allergic, anaphylactic, febrile (nonhemolytic) types of blood transfusion reactions.

Post-transfusion reactions, as a rule, are not accompanied by serious and prolonged disturbances in the function of organs and systems and do not pose an immediate danger to the life of the patient. They manifest, as a rule, 10-25 min after the beginning of blood transfusion, in some cases are noted after the end of blood transfusion and depending on the degree of severity can last from several minutes to several hours.

Pyrogenic reactions (hyperthermia) arise as a result of infusion into the bloodstream of the pyrogen recipient along with canned blood or its components. Pyrogens are nonspecific proteins, the products of microorganisms' vital activity. Posttransfusion pyrogenic reactions may also occur in patients who are isensensitized by repeated blood transfusions or in women who have had a previous pregnancy in the anamnesis in the presence of antileukocytic, antiplatelet or anti-protein antibodies. Filtering blood through leukohypertres and washing can dramatically reduce the risk of isosensitis in patients with multiple blood transfusions.

When pyrogenic reactions occur, a chill appears, the temperature rises to +39 or 40 ° C, usually 1-2 hours after a blood transfusion, less often during it. The fever is accompanied by a headache, myalgia, discomfort in the chest, pain in the lumbar region. The clinical picture can have a different degree of severity. Blood transfusions often occur with a low-grade fever, which usually soon passes. The prognosis for pyrogenic reactions is favorable. Clinical signs disappear after a few hours.

Allergic reactions of varying severity are noted in 3-5% of cases of blood transfusion. As a rule, they are registered in patients, sensitized by previous blood transfusions or having in the anamnesis repeated pregnancies with antibodies to antigens of plasma proteins, leukocytes, platelets and even Ig. In some patients, allergic reactions are observed even with the first transfusion of hemocomponents and are not associated with previous isosensitisation. It is believed that in such cases these reactions are due to the presence of "spontaneous" antibodies to Ig and the response of the IgE of the mast cells of the recipient to the transfused specific antigen of the donor, which is often associated with platelets or plasma proteins.

Allergic reactions can occur both during the transfusion of blood or its components, and delayed, 1-2 hours after the end of the procedure. A characteristic sign of an allergic posttransfusion reaction is an allergic rash, often accompanied by itching. With a more severe course of reaction - chills, headaches, fever, joint pain, diarrhea. It should be borne in mind that an allergic reaction can occur with symptoms of anaphylactic nature - a violation of breathing, cyanosis, sometimes - with the rapid development of pulmonary edema. One of the most formidable complications of blood transfusion is the anaphylactic reaction, which sometimes develops lightly before anaphylactic shock.

According to the severity of the clinical course (body temperature and duration of manifestation), three degrees of posttransfusion reactions are distinguished: light, medium, heavy.

Light reactions are characterized by a slight increase in temperature, headache, a slight chill and malaise, pain in the muscles of the limbs. These phenomena, as a rule, are short-lived - 20-30 minutes. Usually, they do not require any special medical measures for their relief.

Moderately severe reactions - there is an increase in pulse and respiration, a rise in temperature by 1.5-2 ° C, an increasing chill, and sometimes hives occur. In most cases, medication is not required.

Severe reactions - cyanosis of the lips, vomiting, severe headache, pain in the lower back and bones, dyspnea, urticaria or swelling (such as Quincke), body temperature rises by more than 2 ° C, there is tremendous chills, leukocytosis. It is necessary to proceed as soon as possible to medical correction of hemotransfusion complications.

Since the auto-components are immune to the blood of patients, the reactions and complications associated with the transfusion of components of the donor blood, provided all the rules of blood transfusion are observed, are absent.

Interaction

It is not recommended to use glucose solutions (5% glucose solution or its analogues cause gluten and hemolysis of erythrocytes) and solutions containing calcium ions (cause blood clotting and clot formation) for the preparation of EV.

The erythrocyte mass is diluted with physiological solution. The use of the EM solution in a low molecular weight dextran solution in a ratio of 1: 1 or 1: 0.5 reliably preserves the BCC, reduces the aggregation and sequestration of the shaped elements during the operation and on the following day.

Erythrocyte mass in a solution of 8% gelatin with citrate, chloride and sodium bicarbonate is essentially an original blood component - erythrocyte transfuzate, which not only replenishes blood loss and restores the oxygen transport function of the blood, but also has a hemodynamic disaggregating effect with a sufficiently pronounced vollemic effect. The use of 8% gelatin as a preservative with citrate, chloride and sodium bicarbonate allows to prolong the life of the OE up to 72 hours.

Caveats

The erythrocytic mass is stored for 24- 72 hours (depending on the preservative solution) at a temperature of + 4 ° C. Ready-to-use EB, thawed and washed, should have a hematocrit in the range 0.7-0.8 (70-80%). The period of storage of washed EM before use due to the risk of bacterial contamination can be no more than 24 hours at + 1-6 ° C.

The introduction of excessive amounts of EM or EB can lead to hemoconcentration, which reduces CB and thereby worsens hemodynamics in general.

[17], [18], [19], [20], [21], [22], [23], [24], [25]