Blood plasma
From Wikipedia, the free encyclopedia
Blood plasma is the liquid component of blood, in which the blood cells are suspended. Plasma is the largest single component of blood, making up about 55% of total blood volume. Serum refers to blood plasma in which clotting factors (such as fibrin) have been removed. Blood plasma contains many vital proteins including fibrinogen, globulins and human serum albumin. Sometimes blood plasma can contain viral impurities which must be extracted through viral processing.
Plasma resembles whey in appearance (transparent with a faint straw colour). It is mainly composed of water, blood proteins, and inorganic electrolytes. It serves as transport medium for glucose, lipids, amino acids, hormones, metabolic end products, carbon dioxide and oxygen. The oxygen transport capacity and oxygen content (CaO2) of plasma is much lower than that of the hemoglobin in the red blood cells; the CaO2 will, however, increase under hyperbaric conditions.) Plasma is the storage and transport medium of clotting factors. Its protein content is necessary to maintain the oncotic pressure of the blood, which "holds" the serum within the vessels.
[edit] Fresh frozen plasma
Fresh frozen plasma (FFP) is prepared from a single unit of blood. It is frozen after collection and can be stored for one year from date of collection. FFP contains all of the coagulation factors and proteins present in the original unit of blood. It is used to treat coagulopathies from warfarin overdose, liver disease, or dilutional coagulopathy. FFP that has been stored more than a standard length of time is re-classified as simply "frozen plasma," which is identical except that the coagulation factors are no longer considered completely viable.[1]
[edit] Dried plasma
Dried plasma was developed and first used during WWII. Prior to the United States involvement in the war, liquid plasma and whole blood were used. The "Blood for Britain" program during the early 1940s was quite successful (and popular stateside) based in part on Dr.Charles Drew's contribution. A large project was started in August 1940 to collect blood in New York City hospitals for the export of plasma to Britain. Dr. Drew was appointed medical supervisor of the "Plasma for Britain" project. His notable contribution at this time was to transform the test tube methods of many blood researchers, including him, into the first successful mass production techniques.
Nonetheless, the decision was made to develop a dried plasma package for the armed forces because it reduced breakage and made transport, packaging, and storage much simpler. [2]
The resulting Army-Navy dried plasma package came in two tin cans containing 400 cc bottles. One bottle contained enough distilled water to completely reconstitute the dried plasma contained in the other bottle. In about three minutes, the plasma would be ready to use and could stay fresh for around four hours. [3]
Following the Plasma for Britain project, Dr. Drew was named director of the Red Cross Blood Bank and assistant director of the National Research Council, in charge of blood collection for the United States Army and Navy. Drew argued against the armed forces directive that blood/plasma was to be separated by the race of the donor. Dr. Drew argued that there was no racial difference in blood and that the policy would lead to needless deaths as soldiers and sailors had to wait for "same race" blood. [citation needed]
By the end of the war the American Red Cross had provided enough blood for over six million plasma packages. Most of the surplus plasma was returned stateside for civilian use. Serum albumin replaced dried plasma for combat use during the Korean War.[4]
