Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells.
Blood transfusion is the process of transferring blood products into a person's circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but modern medical practice commonly uses only components of the blood, such as red blood cells, white blood cells, plasma, clotting factors and platelets.
Transfusion medicine is the branch of medicine that encompasses all aspects of the transfusion of blood and blood components including aspects related to hemovigilance. It includes issues of blood donation, immunohematology and other laboratory testing for transfusion-transmitted diseases, management and monitoring of clinical transfusion practices, patient blood management, therapeutic apheresis, stem cell collections, cellular therapy, and coagulation. Laboratory management and understanding of state and federal regulations related to blood products are also a large part of the field.
Platelets, also called thrombocytes, are a component of blood whose function is to react to bleeding from blood vessel injury by clumping, thereby initiating a blood clot. Platelets have no cell nucleus; they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow or lung, which then enter the circulation. Circulating inactivated platelets are biconvex discoid (lens-shaped) structures, 2–3 µm in greatest diameter. Activated platelets have cell membrane projections covering their surface. Platelets are found only in mammals, whereas in other vertebrates, thrombocytes circulate as intact mononuclear cells.
Whole blood (WB) is human blood from a standard blood donation. It is used in the treatment of massive bleeding, in exchange transfusion, and when people donate blood to themselves. One unit of whole blood brings up hemoglobin levels by about 10 g/L. Cross matching is typically done before the blood is given. It is given by injection into a vein.
Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, but contains proteins and other constituents of whole blood in suspension. It makes up about 55% of the body's total blood volume. It is the intravascular part of extracellular fluid. It is mostly water, and contains important dissolved proteins, glucose, clotting factors, electrolytes, hormones, carbon dioxide, and oxygen. It plays a vital role in an intravascular osmotic effect that keeps electrolyte concentration balanced and protects the body from infection and other blood-related disorders.
A blood-borne disease is a disease that can be spread through contamination by blood and other body fluids. Blood can contain pathogens of various types, chief among which are microorganisms, like bacteria and parasites, and non-living infectious agents such as viruses. Three bloodborne pathogens in particular, all viruses, are cited as of primary concern to health workers by the CDC-NIOSH: HIV, hepatitis B (HVB), & hepatitis C (HVC).
A blood bank is a center where blood gathered as a result of blood donation is stored and preserved for later use in blood transfusion. The term "blood bank" typically refers to a division of a hospital where the storage of blood product occurs and where proper testing is performed. However, it sometimes refers to a collection center, and some hospitals also perform collection. Blood banking includes tasks related to blood collection, processing, testing, separation, and storage.
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. Donation may be of whole blood, or of specific components directly (apheresis). Blood banks often participate in the collection process as well as the procedures that follow it.
Cryoprecipitate, also called cryo for short, is a frozen blood product prepared from blood plasma. To create cryoprecipitate, fresh frozen plasma thawed to 1–6 °C is then centrifuged and the precipitate is collected. The precipitate is resuspended in a small amount of residual plasma and is then re-frozen for storage. It is often transfused to adults as two 5-unit pools instead of as a single product. One of the most important constituents is factor VIII, which is why cryoprecipitate is sometimes called cryoprecipitated antihaemophilic factor or cryoprecipitated AHF. In many clinical contexts, use of whole cryoprecipitate has been replaced with use of clotting factor concentrates made therefrom, but the whole form is still routinely stocked by many, if not most, hospital blood banks. Cryo can be stored at −18 °C or colder for 12 months from the original collection date. After thawing, single units of cryo can be stored at 20–24 °C for up to 6 hours. If units of cryo are pooled in an open system, they can only be held at 20–24 °C for up to 4 hours. Presently cryo cannot be re-frozen for storage after it is thawed for use if it is not transfused.
Apheresis is a medical technology in which the blood of a person is passed through an apparatus that separates out one particular constituent and returns the remainder to the circulation. It is thus an extracorporeal therapy.
Plateletpheresis is the process of collecting thrombocytes, more commonly called platelets, a component of blood involved in blood clotting. The term specifically refers to the method of collecting the platelets, which is performed by a device used in blood donation that separates the platelets and returns other portions of the blood to the donor. Platelet transfusion can be a life-saving procedure in preventing or treating serious complications from bleeding and hemorrhage in patients who have disorders manifesting as thrombocytopenia or platelet dysfunction. This process may also be used therapeutically to treat disorders resulting in extraordinarily high platelet counts such as essential thrombocytosis.
Fresh frozen plasma (FFP) is a blood product made from the liquid portion of whole blood. It is used to treat conditions in which there are low blood clotting factors or low levels of other blood proteins. It may also be used as the replacement fluid in plasma exchange. Using ABO compatible plasma, while not required, may be recommended. Use as a volume expander is not recommended. It is given by slow injection into a vein.
In England, blood and other tissues are collected by NHS Blood and Transplant (NHSBT). NHSBT Blood Donation was previously known as the National Blood Service until it merged with UK Transplant in 2005 to form a NHS special health authority. Other official blood services in the United Kingdom include the Northern Ireland Blood Transfusion Service, the Scottish National Blood Transfusion Service and the Welsh Blood Service.
Intraoperative blood salvage (IOS), also known as cell salvage, is a specific type of autologous blood transfusion. Specifically IOS is a medical procedure involving recovering blood lost during surgery and re-infusing it into the patient. It is a major form of autotransfusion.
Transfusion-related acute lung injury (TRALI) is the serious complication of transfusion of blood products that is characterized by the rapid onset of excess fluid in the lungs. It can cause dangerous drops in the supply of oxygen to body tissues. Although changes in transfusion practices have reduced the incidence of TRALI, it was the leading cause of transfusion-related deaths in the United States from fiscal year 2008 through fiscal year 2012.
Erythrocytapheresis is an apheresis procedure by which erythrocytes are separated from whole blood. It is an extracorporeal blood separation method whereby whole blood is extracted from a donor or patient, the red blood cells are separated, and the remaining blood is returned to circulation.
Plasma frozen within 24 hours after phlebotomy, commonly called FP24, PF‑24, or similar names, is a frozen human blood plasma product used in transfusion medicine. It differs from fresh-frozen plasma (FFP) in that it is frozen within 24 hours of blood collection, whereas FFP is frozen within 8 hours. The phrase "FFP" is sometimes used to refer to any frozen blood plasma product intended for transfusion.
Pathogen reduction using riboflavin and UV light is a method by which infectious pathogens in blood for transfusion are inactivated by adding riboflavin and irradiating with UV light. This method reduces the infectious levels of disease-causing agents that may be found in donated blood components, while still maintaining good quality blood components for transfusion. This type of approach to increase blood safety is also known as “pathogen inactivation” in the industry.
The Iranian Blood Transfusion Organization or acronymly IBTO is the highest and only decision-making authority in the field of supply and distribution of healthy blood and blood products in Iran. This organization was established in July 31, 1974.
