Blood banks store donated blood to be used in blood transfusion
According to the American Association of Blood Banks, about 13.9 million units (including approximately 695,000 autologous donations) of Whole Blood are donated in the United States each year by approximately eight million volunteer blood donors. These units are transfused to about 4.5 million patients per year. Typically, each donated unit of blood, referred to as Whole Blood, is separated into multiple components, such as Red Blood Cells, Plasma, Platelets and Cryoprecipitate. Each component is generally transfused to a different individual, each with different needs. There is a high demand for blood, and on any given day, approximately 32,000 units of Red Blood Cells are needed. Accident victims, people undergoing surgery and patients receiving treatment for leukemia, cancer or other diseases, such as sickle cell disease and thalassemia, all utilize blood. Approximately 26.5 million units of blood components are transfused each year.
Each unit of whole blood is normally separated into several components. Blood from a blood relative of the patient has a shelf life of 28 days, stored under refrigeration. A non-blood relative's blood has a shelf life of 35 days. The reason for a longer shelf life of non-blood relatives' blood is that donations from blood relatives must be irradiated before use. Irradiation shortens the shelf life by 7 days. Red cells carry oxygen and are used to treat anemia. Platelets, important to control bleeding, have a shelf life of 5 days. Plasma, used to control bleeding due to low levels of some clotting factors, is usually kept in the frozen state for up to one year. Cryoprecipitated AHF, which contains only a few specific clotting factors, is made from Fresh Frozen Plasma and may be stored frozen for up to one year.Granulocytes are sometimes used to fight infections, although their efficacy is not well-established. They must be transfused within 24 hours of donation.