Transfusion Medicine - Jeffrey McCullough

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cells by apheresis was essentially unchanged from 2015, but this represents a valuable portion of the red cell supply of about 15% in 2017 and is particularly helpful in collecting blood from type O donors [26]. Almost all blood is converted into components; however, in 2017, 5,776 units of whole blood were distributed [26]. Of whole blood and red blood cells collected, 5% were not used.

      (Source: Whitaker BI, Rajbhandary S, Harris A. The 2013 AABB blood collection, utilization, and patient blood management survey report. Bethesda, MD: American Association of Blood Banks, October 21, 2015. Reproduced with permission of AABB.)

      Platelet production

      In the United States, most platelets are produced by plateletpheresis, although a few are prepared from whole blood. In 2017, 2.259,000 units of platelets were provided. The number of plateletpheresis procedures was smaller because a median of 1.9 products were obtained from most procedures [26]. This is a 4.6% increase from 2015. Most (93.4%) platelets are prepared and stored in plasma and the remainder in platelet additive solutions [26]. Although most platelets are prepared by plateletpheresis, 221,000 units, or 9% of the supply were prepared, from whole blood (see Chapter 5). Apheresis platelets are used primarily, but as many as 19% were not used in 2017 [26].

      Plasma production for transfusion

Pie chart depicts the use of red blood cell by hospital service in 2013.

      (Source: Whitaker BI, Rajbhandary S, Harris A. The 2013 AABB blood collection, utilization, and patient blood management survey report. Bethesda, MD: American Association of Blood Banks, October 21, 2015. Reproduced with permission of AABB.)

      Plasma increases might be because of production of AB plasma, which now represents a substantial portion of plasma for transfusion, probably because of changes in the management of trauma and acute blood loss (see Chapter 11).

      Certain areas of the United States are chronically unable to collect enough blood to meet their local transfusion needs. This occurs mostly in metropolitan areas that serve large trauma, tertiary, and transplantation centers. This can cause several difficulties, including possible unavailability of blood or components when needed, complex inventory management, technical disparities, emergency appeal‐type donor recruitment, higher costs, decreased independence, and higher‐risk management costs. As the nature of blood supply organizations has changed (see earlier US Blood Supply section), local and regional relationships have weakened, and each organization manages to collect and distribute their products in the most cost‐efficient and revenue‐generating way possible.

      This process of moving blood considerable distances is increasing as hospitals contract with blood suppliers based on cost and availability, breaking long‐time regional or local relationships. This has converted most blood supply organizations into a national perspective.

      Despite the fact that there is not a unified blood banking system or a single national inventory or blood resource–sharing system in the United States, blood suppliers have made major efforts to use blood from areas where it is available in excess. Since 1953, the American Association of Blood Banks (AABB) has operated the National Blood Exchange that coordinates the distribution of many units of blood and components annually. These blood‐sharing systems have become less important as the supply organizations have consolidated and become part of larger organizations that manage their own inventory on a national basis.

      One of the major issues in blood inventory management is the attitude of blood donors. In the only study focused on donors’ attitudes about being asked to donate more blood than is needed by their local community [31], donors to several American Red Cross blood centers indicated a willingness to donate for patients in other areas of the United States as long as their local blood needs were being met.

      In the past, blood centers carried out a variety of activities that provided services in addition to the blood components. These included continuing education for physicians, technologists, and/or nurses; human leukocyte antigen typing; therapeutic apheresis; red cell reference laboratory testing; outpatient transfusions; and medical consultation for transfusion medicine. These services were often provided to hospitals and the medical technical nursing community at little or no extra charge because the activities were subsidized by the income generated from the charges for the blood components. However, as blood centers have attempted to stabilize or reduce their prices to hospitals, it has become necessary for these additional services to become self‐supporting financially. In most situations, hospitals have been unwilling to pay for the services; as a result, blood centers have reduced or eliminated these activities. Blood centers are now more narrowly focused on collecting and distributing blood.

      A method was developed at the beginning of World War II to process large volumes of plasma so that some of the proteins could be isolated, concentrated, and used for medical purposes [32]. This plasma “fractionation” process is the basis for a large industry that provides many medically valuable products generally referred to as plasma “derivatives” [33–35]. The plasma for production of these derivatives is obtained by plasmapheresis. Members of the Plasma Protein Therapeutics Association (PPTA) carry out approximately 44 million plasmapheresis procedures annually and collected about 44 million liters of plasma [35]. There are many US Food and Drug Administration (FDA)–licensable plasma derivatives (see Chapter 5). The production of these plasma derivatives is a complex manufacturing process that takes 7–9 months and usually involves batches up to 10,000 L of plasma or plasma from as many as 50,000 donors (see Plasma Protein Therapeutics Association section later in this chapter).

      Plasma definitions

      The FDA uses two terms for plasma that may serve as the starting material for the manufacture of derivatives: plasma and source plasma. Plasma is “the fluid portion of one unit of human blood intended for intravenous

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