Blood plasma volume expander

Between 1945 and 1955, the Northern Regional Research Center (NRRC) of the U. S. Department of Agriculture was extensively involved in the development of the bacterial polysaccharide dextran as a blood-plasma volume-expander. The dextran program was success-... 

Use Photographic film sizing textile and paper adhesives cements capsules formedicinals matches light filters clarifying agent desserts, jellies, etc. culture medium for bacteria blood plasma volume expander microencapsulation printing inks nutrient protective colloid in ice cream. 

Behen et al. (1964) have developed an infrared method for the quantitative determination of the blood plasma volume expander, polyvinylpyrrolidone, in serum and urine from experimentally infused dogs. 

The biopolymer dextran produced on the basis of the renewable resource sucrose is a very interesting raw material for many applications. It was used first as a blood-plasma volume expander in the 1940s. Up to now, there are... 

To eliminate the threat of shock, replenishment of the circulation is essential. With moderate loss of blood, administration of a plasma volume expander may be sufficient Blood plasma consists basically of water, electrolytes, and plasma proteins. However, a plasma substitute need not contain plasma proteins. These can be suitably replaced with macromolecules ( colloids ) that like plasma proteins, (1) do not readily leave the circulation and are poorly filtrable in the renal glomerulus and (2) bind water along with its solutes due to their colloid osmotic properties. In this manner, they will maintain circulatory filling pressure for many hours. On the other hand, volume substitution is only transiently needed and therefore complete elimination of these colloids from the body is clearly desirable. 

Plasma volume expanders and artificial blood substitutes... 

Plasma volume expanders. If blood is lost during trauma, the loss of volume is more immediately threatening than the loss of red blood cells. Replacement with salt solutions does not work well because small solutes get rapidly filtrated into the interstitial fluid compartment. Only macromolecules are retained in the intravascular space and can prevent filtration of the diluted plasma due to their osmotic activity. Commonly used plasma expanders are metabolically inert polysaccharides such as dextran and hydroxyethyl-starch. 

Dextran (O Scheme 5) solutions have been used as a plasma volume expander since 1947 owing to their non-immunogenic and well-tolerated nature as plasma substitutes [10]. Furthermore, since dextran suppresses erythrocyte aggregation and reduces blood viscosity, it has... 

Williams and Wilkins, 1996. ISBN 06-8330-0318. Organized into five major sections principles of poison management, drugs, the home, chemicals, and natural toxins. There are chapters on AIDS and antiviral drugs, drug toxicology, blood transfusions, cytokines, plasma volume expanders, the gastrointestinal tract, etc. 

The plasma volume expanders are the substances that are transfused to maintain fluid volume of the blood in event of great necessity, supplemental to the use of whole blood and plasma. Some starch derivatives like hydroxyethyl starch and acetyl starch, which are a group of coUoids, are used to provide sustained intravascular volume expansion. Hydroxyethyl starches are high-polymeric compounds obtained via hydrolysis and subsequent hydroxyl ethylation of glucose units substituted at carbon number 2, 3, and 6 of starch. Recently some waxy starches were also evaluated for plasma volume expander, but more research is needed to establish them as a good substitute for the synthetic polymers. 

Dissolved in normal saline with a concentration of about 6%, dextran exhibits similar colloid osmotic pressure and viscosity as human blood. Therefore, dextran has been used as plasma volume expander for several decades.Dextran 40 and 70, with molecular weight of 40 and 70 kDa, respectively, are prescribed for the treatment of shock or impending shock due to hemorrhage, bums, or trauma. 

Poly(N-vinyl-pynolidinone) (or PVP) is a widely used water-soluble polymer. Similar to dextran, it has been used as a plasma volume expander to replace lost blood in mass-casualty situations. PVP can also be used as a detoxifying agent many toxic compounds form nontoxic complexes with PVP, which the kidneys eventually excrete. PVP is also used extensively as a binder in the pharmaceutical industry. 

Taking into account the biocompatibility and blood compatibility of poly(N-vinyl-pyrrolidone), used as plasma volume expander, Maria Azori and coworkers studied the biocompatibility of the alternant copolymer of maleic anhydride with... 

Whole blood is seldom used ia modem blood transfusion. Blood is separated into its components. Transfusion therapy optimizes the use of the blood components, using each for a specific need. Red cell concentrates are used for patients needing oxygen transport, platelets are used for hemostasis, and plasma is used as a volume expander or a source of proteins needed for clotting of the blood. 

History. Methods for the fractionation of plasma were developed as a contribution to the U.S. war effort in the 1940s (2). Following pubHcation of a seminal treatise on the physical chemistry of proteins (3), a research group was estabUshed which was subsequendy commissioned to develop a blood volume expander for the treatment of military casualties. Process methods were developed for the preparation of a stable, physiologically acceptable solution of alburnin [103218-45-7] the principal osmotic protein in blood. Eady preparations, derived from equine and bovine plasma, caused allergic reactions when tested in humans and were replaced by products obtained from human plasma (4). Process studies were stiU being carried out in the pilot-plant laboratory at Harvard in December 1941 when the small supply of experimental product was mshed to Hawaii to treat casualties at the U.S. naval base at Pead Harbor. On January 5, 1942 the decision was made to embark on large-scale manufacture at a number of U.S. pharmaceutical plants (4,5). 

The IV solutions of plasma expanders include hetastarch (Hespan), low-molecular-weight dextran (Dextran 40), and high-molecular-weight dextran (Dextran 70, Dextran 75). Plasma expanders are used to expand plasma volume when shock is caused by bums, hemorrhage surgery, and otiier trauma and for prophylaxis of venous thrombosis and diromboembolism. When used in die treatment of shock, plasma expanders are not a substitute for whole blood or plasma, but tiiey are of value as emergency measures until die latter substances can be used. 

Compartment 1 represents the vascular space of the tissue and can be identified as either a blood, plasma, or serum space. Compartment 2 is the interstitial space, and compartment 3 the intracellular tissue volume. Assuming first-order or linear membrane transport for the drug, the flux terms can be expanded as... 

Bulk flow plays only a minor role in the exchange of specific solutes between blood and tissue cells. A far more important function of bulk flow is to regulate distribution of extracellular fluid between the vascular compartment (plasma) and the interstitial space. Maintenance of an appropriate circulating volume of blood is an important factor in the maintenance of blood pressure. For example, dehydration and hemorrhage will cause a decrease in blood pressure leading to a decrease in capillary hydrostatic pressure. As a result, net filtration decreases and net reabsorption increases, causing movement, or bulk flow, of extracellular fluid from interstitial space into the vascular compartment. This fluid shift expands the plasma volume and compensates for the fall in blood pressure. 

Patients are initially grouped by independent measurements of red cell mass and plasma volume. Where the latter is contracted the increase in packed red cell volume or haemoglobin in the peripheral blood is spurious or relative. In true erythrocytosis the red cell mass, and often the plasma volume, are both expanded. These individuals are further subdivided, depending upon whether tissue oxygenation is impaired, with consequent activation of normal physiological mechanisms. Conversely, this situation may reflect pathological production of erythropoietin or uncontrolled overgrowth of red cells in the chronic myeloproliferative syndrome. 

Human plasma has a colloid osmotic pressure of 3.6 kPa, of which 2.8 kPa is contributed by albumin. Volume-for-volume, 4.5% albumin is approximately four times more effective in expanding the plasma volume than crystalloid solutions, and the effect lasts 6-8 hours, compared to only 15-20 min with crystalloids. Although popular in the past as volume expanders, albumin solutions have fallen into disfavour. They are prepared from pooled human plasma, with all the inherent risks of pooled blood products. Albumin can cause adverse reactions, similar to other transfusion reactions, such as chills, urticaria, and vasodilatation. These may be caused by organic or inorganic substances formed during the processing... 

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