Risks associated with red blood cell transfusions: potential benefits from application of pathogen inactivation

Kleinman, Steve; Stassinopoulos, Adonis

The 2011 HHS National Blood Collection and Utilization Survey estimated a mean per-patient RBC dose of 2.75 units annually, 2 and a 5-year retrospective study in a regional hospital system reported a mean of 2.9 (62.7) RBC units per transfused inpatient. 3 However, there is substantial interpatient variability in RBC units transfused due to clinical diagnoses of the patient, the indication for transfusion, long established physician practice patterns, and the presence or absence of patient blood management programs. Figure 1 provides a theoretical schema for understanding a recipient's risk of acquiring a transfusion-transmitted infection, which is dependent on two factors: the number of units transfused (e.g., a higher risk with more units) and whether transfusion occurs when an undetected emerging infectious agent (EIA) is in the blood supply. This latter time-related risk is higher for recipients whose transfusion exposure spans a longer time interval. 1, 4 Factors relevant to clinical outcome of a transfusion-transmitted infection include the expected length of recipient survival due to underlying disease and the increased susceptibility of different patient populations (based on their degree of immunosuppression) to adverse clinical outcomes secondary to infectious disease transmission. 5 Thus, a logical way to categorize RBC recipients is both by number of units transfused and by the time interval over which transfusions occur. In Table 1 , [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] which forms the basis of a per-patient risk analysis for selected patient groups, we synthesized existing RBC usage and transfusion practice data for illustrative diagnoses into a five-tiered classification scheme based on acute (single transfusion episode), intermittent (multiple episodes), or chronic (often lifetime) RBC transfusion therapy.