Blood procurement is a vital national priority that is met in the United States (U.S.) by volunteer donors and a pluralistic blood collection program that includes the American Red Cross, independent community blood centers, and hospitals. Approximately 12 million units of whole blood are collected from approximately 9 million donors annually.1,2 Recruitment of donors is preceded by a medical history and limited physical examination. The donated blood is subjected to tests of blood type, red cell antibodies, and infectious agents that may be transmitted by blood transfusion. In some cases, collection of red cells, platelets, leukocytes, or plasma is achieved by hemapheresis. Plasma for the subsequent manufacture of derivatives such as albumin and IV immunoglobulin is obtained from paid donors by for-profit organizations different from those that collect whole blood and prepare blood components. The meticulous attention to donor risk characteristics and the use of sensitive assays to detect infectious agents that may be transmitted by blood have greatly improved the safety of blood.
It is widely accepted that red blood cell (RBC) transfusions save lives and prevent ischemic-related morbidity in severely hemorrhaging patients and those with acute anemia (hemoglobin [Hb] <60 g/L). When a patient’s Hb level exceeds 100 g/L, oxygen delivery and consumption do not necessarily increase with RBC transfusions. For patients in the 60 to 100 g/L Hb “gray zone,” the benefit of a transfusion will depend on a patient’s clinical status, and should be weighed against the inherent risks of allogeneic blood, but primarily these patients do not benefit from transfusion (see later in this chapter).
These risks include adverse reactions, which occur in up to 3% of transfusions. Transfusion-related acute lung injury is the number one cause of transfusion-related fatalities, and new pathogens causing transfusion-transmitted infections continue to pose a threat to the blood supply. Transfusion-associated circulatory overload is often not recognized, but has been associated with increased morbidity and prolonged lengths of hospital stay.
As the older population grows in the U.S., the demand for blood will increase, even as the donor population declines. Patient blood management efforts are growing in popularity as hospitals grapple with the risks and costs associated with transfusion. The implementation of evidence-based practice is the best way to benefit patients and minimize the risks of transfusion.
OVERVIEW OF THE BLOOD SUPPLY SYSTEM IN THE UNITED STATES
The United States (U.S.) has a pluralistic rather than a single national system of blood collection that exists in other developed countries. During 2017, approximately 12.2 million units of blood were available for use in the U.S. (Table 138–1). This was a 3.3% decrease from 2015. Approximately 96% of the blood was collected in regional blood centers, and hospitals collected 4%.1 Less than 1% of the units donated in the U.S. were autologous donations or directed donations—that is, blood given by family or friends for a specific patient. Although autologous donations ...