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Periodically the CDC surveys blood collection organizations and hospitals to determine the blood supply and utilization [26]. The most recent report is from 2017, when data were obtained from 88% of blood suppliers and 80% of hospitals. In 2017, 10,397,000 units of allogeneic whole blood and 10,000 units of autologous blood were collected [26]. An additional 1,794,000 units of red cells (15%) was collected by apheresis, giving a total of 12,201,000 units. Laboratory testing led to discard of 78,000 (0.6%), and an additional 590,000 units was not suitable for use, leaving a total of 11,533,000 units available for transfusion [26].

There have been several trends in the nation’s blood supply since the 1970s, partly influenced by the AIDS epidemic. From 1980 to 1988, there was an increase in the amount of allogeneic blood collected [25] (Figure 2.1). Between 1988 and 1998, there was a substantial increase followed by an increase and then plateau from 1997 to 2008. However, a substantial decrease has occurred since then, with a 3% decrease from 2015 to 2017 [26]. The decrease in collections reflects a decreased use of 6.8% from 2015 to 2017 [26]. Autologous donations showed a surprising increase of 35%, although the number of units was very small (27,000) [26]. Collection of red 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.

Figure 2.1 US allogeneic white blood/red blood cell collections and transfusions, 1989–2013.

(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.)

General medicine, surgery, and hematology‐oncology transplant patients are the largest users of red blood cells (Figure 2.2). In times of inventory shortage, conserving or postponing elective transfusions to medical patients conserves a larger proportion of the red cell supply than canceling major elective surgery [30].