From Big Medical Encyclopedia

TROMBOTSYTNY WEIGHT (Greek thrombos a piece, a clot + kytos a receptacle, here — a cell; synonym: a concentrate of thrombocytes, trombokon-tsentrat) — the transfusion environment containing the thrombocytes weighed in plasma received from donor blood. Main objective of transfusion of T. m — to provide a hemostasis (see): to stop or warn the bleeding, bleeding connected with a lack of thrombocytes (see) in the circulating blood or with their qualitative inferiority.

T. m receive by means of serial centrifuging, a trombo-tsitaferez using plasti-katny containers or a trombotsi-taferez using automatic separators, or devices for fractionation of blood (see the Plasma exchange). Serial centrifuging at various modes allows to receive T. m from the plasma enriched with thrombocytes and from leu-kotrombotsitarnogo of a layer of stored blood. The dose of stored blood (500 ml) no more than through 4 — after preparation would be subjected hour to the first (soft) centrifuging in plastikatny containers. At the same time erythrocytes and leukocytes are besieged, and in over - a sedimentary layer there is a plasma enriched with thrombocytes. It is placed in a separate container and subjected to the second, more rigid centrifuging. The Nadosadochny plasma which is grown poor by thrombocytes is separated, and in draft receive T. m, the containing 0,55 X 1011 — 0,7 X HYu11 of cells in 30 — 50, ml of plasma.

The plateletpheresis using plastikatny containers consists in numerous step-by-step capture of blood (400 ml) from one donor, its centrifuging and allocation of T. m from the plasma enriched with thrombocytes and then in return to the donor of the eritrotsitny weight and plasma which is grown poor by thrombocytes. Quadruple holding this procedure during one session allows to receive T. m, containing on average 3 X 10y cells. Trombotsitaferez using automatic separators allows to receive from one donor! —

6 X 1011 thrombocytes.

Safety of functional activity of the thrombocytes allocated from stored blood depends on composition of haemo preservative, a time slice from the moment of preparation of blood until allocation of thrombocytes, the mode of centrifuging, volume of plasma, the area and gas permeability of plastikatny containers, temperature and storage period of T. m.

If T. m do not use for transfusions in the next few hours after preparation, store it during

24 hours at the room temperature (20 — 22 °) or at a temperature of 4 °. During this time the majority of the main functional and biochemical indicators of full value of cells remains at the satisfactory level. At the room temperature and constant automatic rocking of containers with thrombocytes they can be stored during 72 hours, and at use of plastikatny containers with the increased gas permeability the shelf-life can be even more extended. Thrombocytes, to-rye were stored at the room temperature, is longer circulate in a vascular bed (have high survival) though their maximum haemo static action is shown a bit later. Storage at a temperature of 4 ° shortens time of life of thrombocytes in a blood channel of the recipient, t. e, reduces their survival. However transfusions of such cells allow to gain immediate gemostatiche-sky effect. Long-term storage of thrombocytes is provided with cryoconservation with use of the special modes of freezing and kriofilaktik (see Conservation of blood).

Transfusions of T. m apply according to strict indications, to-rye are defined not only number of thrombocytes (see) in blood of the patient, and a wedge, inspections of the patient and taking into account a pathogeny of thrombocytopenia are established individually later full (see).

Indications to transfusion of T. m are various diseases and syndromes, at to-rykh as a result of decrease in a thrombocytopoiesis, the increased not immune consumption or disintegration of thrombocytes are noted thrombocytopenia or a trombotsito-patiya (see) with the phenomena of hemorrhagic diathesis (bleedings or bleeding during operation or in the postoperative period or their threat, extracorporal blood circulation, aplastic or hypoplastic anemia, leukoses, oppression of a marrowy hemopoiesis as a result of radiation therapy or treatment of cytostatics, medicamentous or other intoxication, the disseminated intravascular coagulation in a phase of hypocoagulation). The wedge, experience shows that in the absence of hemorrhages and when an operative measure, radiation, treatment of a tsp-tostatikama, etc. is not supposed, thrombocytopenia in itself (70 Ltd companies — 40 Ltd companies of cells in 1 mkl blood) is not the basis for transfusion of T. m. Efficiency of transfusions of T. the m in many respects depends on a dosage, repeated use and other factors. It is estimated by hl. obr. on a wedge, to signs: to absence new and to stopping of the being available displays of hemorrhagic diathesis (see).

The T is considered the minimum therapeutic dose. m, allocated from

2 l of stored blood and containing on average 2,0 X 1011 cells. Transfusion of such or bigger quantity of thrombocytes provides, as a rule, necessary ge-mostatichesky effect and increase in number of the circulating thrombocytes. In some cases increase in number of cells in blood of the recipient can not be noted though clinically expressed decrease in bleeding, disappearance of petechias on skin and mucous membranes, stopping nasal, uterine, went. - kish. and other bleedings confirms efficiency of transfusions.

Transfusion of svezhezagotovlenny stored blood instead of T. m it is inexpedient since its usual doses (250 — 1000 ml) do not provide introduction of a hemostasis of quantity of thrombocytes, necessary for achievement, and repeated transfusions of supermassive doses (2 — 6 l and more) are dangerous since they can lead to circulator disturbances (see Hemotransfusion).

The poured thrombocytes circulate in a blood channel of the recipient up to 7 — 9 days, however gradually them содеря^ание decreases, and again there is a danger of hemorrhages. After repeated transfusions duration of circulation of the poured thrombocytes and their haemo static efficiency decrease, hemotransfusionic reactions owing to isoimmunization can appear (see Hemotransfusion). In these cases transfusions of T are most acceptable. m, prepared by means of a trombotsptaferez from one specially picked up donor.

Apply T to a short-term course of therapy (4 — 6 transfusions). m, received from the donors compatible on system of AB0 antigens and a Rhesus factor. At repeated transfusions, emergence of hemotransfusionic reactions and refractory sti to therapy selection of donors for antigens of the HLA system is necessary (see Immunity transplant, histocompatibility antigens, t. 20, additional materials); for this purpose the immediate family of the recipient is attracted, first of all.

Transfusions of T. m make by means of plastikatny system for hemotransfusion, to-ruyu attach to a container with T. m; after the termination of a transfusion from one container attach the following containers to the same system.

Reactions to transfusion of T. m carry hl. obr. allergic character (urticaria, an itch, fever, nausea, hypostases, etc.) are also connected with the developing isoimmunization as a result of repeated transfusions. Apply the hyposensibilizing means (Dimedrol, Suprastinum, calcium chloride, corticosteroids), and also cardiovascular means to their elimination. For the prevention of reactions, especially at repeated transfusions, individual selection of T is necessary. m taking into account antibodies of the recipient and in nek-ry cases introduction before a transfusion of antihistaminic drugs (see. And ntigistaminny substances). Bibliography: Agranenko V. A., L and - with about in with to and I am I. L. and the Company A. M. Functional full value of thrombocytes in stored blood of 1 — 7 days of storage, Probl. gema-tolite. and modulation, blood, t. 26, No. 2, page 36, 1981; Bar kagan 3. C. Hemorrhagic diseases and syndromes, page 113, M., 1980; Vorobyov A. I. and a shouting about d e c to and y V. M. Trombotsitnaya the weight (methods of receiving and efficiency of a clinical use), Probl. gema-tolite. and modulation, blood, t. 25, No. 10, page 26, 1980; Kriokoneervirovaniye of cellular suspensions, under the editorship of A. A. Tsugayeva, page 107, Kiev, 1983; Lisovskaya I. L. and Agranenko V. A. A new method of preparation of functionally active concentrates of thrombocytes from stored blood of 1 — 5 days of storage, Gematol. and transfuziol., t. 28, No. 10, page 55, 1983; The Guide to the general and clinical transfusiology, under the editorship of B. V. Petrovsky, page 81, 168, M., 1979; The reference book on hemotransfusion and blood substitutes, under the editorship of O. K. Gavrilov, page 61, M., 1982; Chernyak N. B., etc. Use of plastikatny containers for receiving a concentrate of thrombocytes at a temperature of 22 °C, Probl. gematol. and modulation. blood, t. 24, No. 11, page 54, 1979; The blood platelet in transfusion therapy, ed. by T. J. Greenwalt a. G. A. Jamieson, N. Y., 1978. V. A. Agranenko.