Articles on Medical Diseases and Conditions

Entries for the ‘Blood Transfusions’ Category

Other Procedures Relevant To Transfusion Therapy

Apheresis Apheresis is a technique in which blood is withdrawn from a donor, one or more substances are removed from the blood, and the blood is then returned to the donor. Most present-day apheresis equipment is based on separation of blood components by differential centrifugation. Apheresis has two major applications. One is the removal of […]

Red Blood Cell Substitutes

Attempts have been made to find an RBC substitute that will not require crossmatching, can be stored conveniently for long periods of time, can be excreted or metabolized in a reasonable period of time, is relatively nontoxic, and can provide an adequate delivery of oxygen to body tissues and return carbon dioxide to the lungs. […]

Albumin and Purified Plasma Protein Fraction

As mentioned in the earlier discussion about plasma, 5% albumin can be used instead of plasma to restore colloid oncotic pressure, mainly in hypovolemic shock due to massive acute blood loss or extensive burns. About 40% of body albumin is intravascular, with the remainder being in extracellular fluid. In a normal-sized person, 500 ml of […]

Fibrinogen

Fibrinogen is a blood fraction that is essential for clotting. It is decreased in two ways, both relatively uncommon: (1) by intravascular deposition of fibrin in the form of small clots (DIC) and (2) by inactivation in the presence of primary fibrinolysin. Fibrinogen concentrates used to be prepared commercially but are no longer available due […]

Special Coagulation Factor Materials

Factor VIII concentrate differs from cryoprecipitate in several ways. It is prepared from a pool of donors and is lyophilized. The two major advantages are that factor VIII activity has been assayed by the manufacturer for each concentrate bag and that treatment with solvent-detergent mixtures or adequate heat (when coupled with donor testing) can virtually […]

Cryoprecipitate

Cryoprecipitate is prepared from fresh frozen plasma; it is the material that does not become totally liquid when fresh frozen plasma is slowly thawed and the major part has liquefied. Cryoprecipitate contains about 50% of the original factor VIII and von Willebrand factor activity, about 20%-40% of the fibrinogen and some factor XIII. The major […]

Plasma

Plasma itself may be either stored or fresh frozen. Stored plasma until the early 1970s was the treatment of choice for blood volume depletion in burns and proved very useful as an initial temporary measure in hemorrhagic shock while whole blood was being typed and crossmatched. It was also useful in some cases of shock […]

Granulocytes (Neutrophils)

WBC transfusions are being used for treatment of infections not responding to antibiotics in patients with severe leukopenia due to acute leukemia or bone marrow depression. The AABB recommends 500 granulocytes/mm3 (or per microliter) as the cutoff point defining severe leukopenia. Clinical improvement has been reported in some of these patients but not all. Most […]

Platelets

Platelets are supplied in units that are equivalent to the number of platelets in one unit of whole blood (about 5.5 x 1010). These are obtained as single platelet units from random-donor whole blood units or as multiple platelet units from a single donor by means of platelet apheresis. Platelets are stored at room temperature […]

Leukocyte-Poor Blood Products

There are several indications for leukocyte removal. The most frequent reason is development of an immune reaction to antigens on “foreign” transfused leukocytes that constitutes the great majority of febrile nonhemolytic transfusion reactions and by far the most common overall transfusion reaction, especially in multitransfused patients. Second, removal of leukocytes helps prevent microaggregates (miniclots) of […]