A blood transfusion may refer to several procedures in which blood components are isolated and then injected into a recipient. With this procedure, a small amount of donor blood can be used to help a several recipients. The blood components typically injected include red and white blood cells, clotting agents, and plasma. Prior to surgery, a patient can also opt to donate some of his own blood in case he needs a blood transfusion later.
One of the most common blood transfusion procedures involves injecting a recipient with red blood cells. These blood cells are sometimes referred to as packed red blood cells. They also last longer than any other components of the blood. When frozen properly, they can last as long as ten years.
Red blood cells help carry oxygen to every part of the body, so they are often injected into a recipient whose blood is not carrying enough oxygen. Patients with anemia, for example, may receive this type of blood transfusion. If a patient has lost a large amount of blood, he may also receive a red blood cell transfusion.
White blood cells may also be given to a recipient during some blood transfusion procedures. Since white blood cells help fight infection, this is usually done for patients trying to fight a serious infection, especially those with abnormal or inadequate white blood cells. In recent years, however, these types of blood transfusion procedures have become rare, due to more advanced infection-fighting agents, like antibiotics.
Clotting agents may also be injected during some blood transfusion procedures. Platelets are one type of clotting agent. Patients with an insufficient amount of platelets, such as those with thrombocytopenia, can bleed to death, even from a relatively minor wound. Injecting platelets can help stop this from occurring.
Blood clotting factors are proteins found in the blood plasma. These often work in conjunction with platelets to help clot the blood when necessary. Patients with hemophilia may not have enough blood clotting factors, and they will often benefit from blood transfusion procedures that inject these proteins.
Plasma is the fluid, or watery, part of the blood. This also contains blood clotting factors, and it is sometimes used during blood transfusion procedures when other clotting agents are unavailable. It is also injected into patients who can not produce enough blood clotting factors of their own.
Autologous blood transfusions are increasingly popular. This refers to blood transfusion procedures in which patients donate their own blood to be used in later transfusions. Since the blood comes from the patients themselves, there is usually little or no risk of disease or incompatibility that is associated with traditional blood transfusions. This type of procedure is usually done before a patient undergoes surgery or medical procedure that may result in a blood transfusion.