BLOOD PLASMA (grech, plasma molded, issued) — the liquid part of blood consisting of the salts dissolved in water, carbohydrates, proteins and biologically active compounds.
Plasma contains apprx. 90% of water, 7 — 8% of protein, 1,1% of other organic matters and 0,9% of inorganic components. Osmotic pressure of plasma and blood serum makes 7,6 atm, relative viscosity on water is in limits 1,5 — 1,75, index of refraction — 1,34850, pH of plasma on average 7,4. The plasma circulating in a circulatory bed transfers biologically active agents and products of metabolism; has high colloid osmotic pressure and provides constancy of volume of intravascular liquid and alkaline and acid balance of an organism.
A blood plasma, possessing a wide range of medicinal properties, it is used in several types. Native (liquid) plasma is separated after spontaneous sedimentation of cellular components of blood during 24 — 48 hours filtering through membranes, centrifuging (artificial gravitation). It is the most rational to receive plasma by method plasma exchange (see), allowing to keep completely its biological and medicinal properties. At storage of native plasma labile components lose stability and activity within several hours. In the absence of need or an opportunity to immediately use svezhezagotovlenny native plasma it freeze (the frozen plasma) and store at a temperature — 25 ° below (see. Conservation of blood ). Such plasma almost completely keeps to lay down. properties and after thawing at a temperature of 37 — 38 ° it can be used for transfusion.
In need of long-term storage of P. to. dry up by method lyophilizing (see); medical value dry (lyophilized plasmas over time decreases in connection with loss of activity of blood-coagulation factors and a denaturation of a part of proteinaceous components.
The concentrated native plasma is received along with An-tigemofilnym drug — cryoprecipitate which is a concentrate of blood-coagulation factors of VIII (see. Hemophilia ). After department from fresh plasma of a factor VIII and water contents in it crude protein, proteinaceous components, including blood-coagulation factors of IX, increases.
The plasma received immediately after capture of blood at the donor having the high content of a prothrombokinase — anti-haemo-filnaya plasma — is produced in the frozen or dried up look and is applied to treatment and prevention of bleedings at the patients having A.
Plazm's hemophilia of donors actively immunizirovanny by various antigens — immune plasm — has the expressed specificity owing to the high content of antibodies to antigens which immunized donors. It is effective at treatment and prevention of infectious diseases. From immune plasm prepare immunoglobulins directed, or specific, actions.
The blood plasma is issued institutions of service of blood in plastikatny bags (polymeric containers — Gemakon, kompoplast) or glass bottles on 100 — 300 ml. Native plasma is applied right after its separation from cellular components of blood (not later than in 3 — 4 days). A shelf-life of the frozen plasma till 1 year, dry plasma up to 5 years.
Before P.'s transfusion to. check for an exception of a poor quality. It shall keep light yellow color (at infection has dim, grayish-brown color, becomes opaque). Identification in liquid plasma of a suspension, deposit, film, discoloration, and also emergence of opacification, off-flavor is the basis for flat refusal of its use. In the presence of small flakes of fibrin and insignificant opalescence (especially after dissolution it is long the stored dry plasma) plasma should be poured via the filter — standard system for hemotransfusion. For transfusion use plasma of the same group, as a blood group of the patient. Prepost triple biol. test on individual compatibility (to the patient enter 15 — 20 drops of drug, then 10 ml and 20 ml with a break 3 min.). In the absence of reaction at the patient enter all plasma.
Plasma is entered at shock, depending on indicators of a hemodynamics in a dose of 500 — 2000 ml intravenously (struyno or kapelno), vnutrikostno; at proteinaceous insufficiency — intravenously, kapelno, repeatedly on 250 — 500 ml (daily or every other day) before achievement of therapeutic effect; as disintoxication means — intravenously, struyno or kapelno on 250 — 500 ml. At the hypostases, injuries of a skull proceeding with cerebral hypertensia and also at contraindications to introduction of a large amount of liquid, transfusion of the native concentrated or dry plasma dissolved in the small volume of physiological solution is recommended. With the haemo static purpose it is necessary to pour svezhezagotovlenny plasma or the concentrated native plasma, the frozen plasma. For a stop of bleeding it is recommended to use dry plasma a shelf-life no more than 10 days.
In children's practice depending on indications appoint native and dry plasma in a daily dose at the rate of respectively 5 — 8 ml and 3 — 5 ml to 1 kg of weight of the child.
At P.'s use to. emergence of the allergic reactions connected with the increased individual sensitivity of the recipient is possible. In these cases it is necessary to stop a transfusion and to carry out symptomatic therapy according to indications (see. Hemotransfusion ).
Bibliography: Problems of hematology and transfusiology, under the editorship of O. K. Gavrilov, t. 1, M., 1976; The Guide to the general and clinical transfusiology, under the editorship of B. V. Petrovsky, M., 1979; The plasma proteins, ed. by F. W. Putnam, v. 3, p. 545, N. Y. a. o., 1979.
B. M. Rusanov.