A blood product is any component of the blood which is collected from a donor for use in a blood transfusion. Whole blood is uncommonly used in transfusion medicine at present; most blood products consist of specific processed components such as red blood cells, blood plasma, or platelets.
Blood products may also be called blood-based products to differ from blood substitutes, which generally refer to artificially produced products. Whole blood may be classified as a blood product or as a separate entity. Also, although many blood products have the effect of volume expansion, the group is usually distinguished from volume expanders, which generally refer to artificially produced substances and are thereby within the scope of blood substitutes.
Transfusion medicine (or transfusiology) is the branch of medicine that is concerned with the transfusion of blood and blood components. The blood bank is the section of the clinical laboratory where medical technologists process and distribute blood products under the supervision of a medical director, often certified in Pathology or Transfusion Medicine. The blood donor center, also under the supervision of a physician who may be a Transfusion Medicine specialist, is the facility that collects and processes blood products. Transfusion medicine is a board-certified specialty recognized by the American Board of Pathology.]citation needed[ Physicians from a wide range of backgrounds, including pathology, hematology, anesthesiology and pediatrics, are eligible for board certification in Transfusion Medicine following a 1-2 year fellowship.
Physicians certified in Transfusion Medicine are trained in blood product selection and management, immunohematology, apheresis, stem cell collection, cellular therapy, and coagulation. They are often considered a consultant for physicians who require expertise advice on the subjects listed above.
A blood donation occurs when a person voluntarily has blood drawn and used for transfusions and/or made into biopharmaceutical medications by a process called fractionation (separation of whole-blood components). Donation may be of whole-blood (WB), or of specific components directly (the latter called apheresis). Blood banks often participate in the collection process as well as the procedures that follow it.
In the developed world, most blood donors are unpaid volunteers (voluntary non remunerated repeat donations, VNRD) who donate blood for a community supply. In poorer countries, established supplies are limited and donors usually give blood when family or friends need a transfusion (directed donation). Many donors donate as an act of charity, but some are paid and in some cases there are incentives other than money such as paid time off from work. Donors can also have blood drawn for their own future use (autologous donation). Donating is relatively safe, but some donors have bruising where the needle is inserted or may feel faint.
Blood plasma is the straw-colored/pale-yellow liquid component of blood that normally holds the blood cells in whole blood in suspension. It makes up about 55% of total blood volume. It is the intravascular fluid part of extracellular fluid (all body fluid outside of cells). It is mostly water (92% by volume), and contains dissolved proteins (i.e.—albumins, globulins, and fibrinogen), glucose, clotting factors, electrolytes (Na+, Ca2+, Mg2+, HCO3- Cl- etc.), hormones and carbon dioxide (plasma being the main medium for excretory product transportation). Plasma also serves as the protein reserve of the human body. It plays a vital role in an intravascular osmotic effect that keeps electrolytes in balanced form and protects the body from infection and other blood disorders.
Blood plasma is prepared by spinning a tube of fresh blood containing an anticoagulant in a centrifuge until the blood cells fall to the bottom of the tube. The blood plasma is then poured or drawn off. Blood plasma has a density of approximately 1025 kg/m3, or 1.025 g/l.
Apheresis (ἀφαίρεσις (aphairesis, “a taking away”)) is a medical technology in which the blood of a donor or patient is passed through an apparatus that separates out one particular constituent and returns the remainder to the circulation. It is thus an extracorporeal therapy.