Background Although previous studies have identified an association between the transfusion of relatively older red blood cells (RBCs) (storage ≥14 days) and adverse outcomes, they are difficult to interpret because the majority of patients received a combination of old and fresh RBC units. To overcome this limitation, we compared in-hospital mortality among patients who received exclusively old versus fresh RBC units during the first 24 hours of hospitalization. Methods Patients admitted to a Level I trauma center between January 2000 and May 2009 who received ≥1 unit of exclusively old (≥14 days) vs. fresh (<14 days) RBCs during the first 24 hours of hospitalization were identified. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated for the association between mortality and RBC age, adjusted for patient age, Injury Severity Score, gender, receipt of fresh frozen plasma or platelets, RBC volume, brain injury, and injury mechanism (blunt or penetrating). Results One thousand six hundred forty-seven patients met the study inclusion criteria. Among patients who were transfused 1 or 2 RBC units, no difference in mortality with respect to RBC age was identified (adjusted RR, 0.97; 95% CI, 0.72–1.32). Among patients who were transfused 3 or more RBC units, receipt of old versus fresh RBCs was associated with a significantly increased risk of mortality, with an adjusted RR of 1.57 (95% CI, 1.14–2.15). No difference was observed concerning the mean number of old versus fresh units transfused to patients who received 3 or more units (6.05 vs. 5.47, respectively; p = 0.11). Conclusion In trauma patients undergoing transfusion of 3 or more RBC units within 24 hour of hospital arrival, receipt of relatively older blood was associated with a significantly increased mortality risk. Reservation of relatively fresh RBC units for the acutely injured may be advisable.

Prehospital SI>0.9 identifies patients at risk for MT who would otherwise be considered relatively normotensive under current prehospital triage protocols. The risk for MT rises substantially with elevation of SI above this level. Further evaluation of SI in the context of trauma system triage protocols is warranted to analyze whether it triage precision might be augmented among blunt trauma patients with SBP>90 mm Hg.

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Morphologic and biochemical changes occur during red cell storage prior to product expiry, and these changes may hinder erythrocyte viability and function following transfusion. Despite a relatively large body of literature detailing the metabolic and structural deterioration that occurs during red cell storage, evidence for a significant detrimental clinical effect related to the transfusion of older blood is relatively less conclusive, limited primarily to observations in retrospective studies. Nonetheless, the implication that the transfusion of old, but not outdated blood may have negative clinical consequences demands attention. In this report, the current understanding of the biochemical and structural changes that occur during storage, known collectively as the storage lesion, is described, and the clinical evidence concerning the detrimental consequences associated with the transfusion of relatively older red cells is critically reviewed. Although the growing body of literature demonstrating the deleterious effects of relatively old blood is compelling, it is notable that all of these reports have been retrospective, and most of these studies have evaluated patients who received a mixture of red cell units of varying storage age. Until prospective studies have been completed and produce confirmative results, it would be premature to recommend any modification of current transfusion practice regarding storage age. In 1917, Frances Payton Rous and J.R. Turner identified that a citrate-glucose solution allowed for the preservation of a whole blood unit for up to five days, thus facilitating the formative practice of blood banking. Later, Loutit and Mollison of Great Britain developed the first anticoagulant of the modern era, known as acid-citrate-dextrose (ACD). ACD extended the shelf life of refrigerated blood to 21 days, and ACD remained in wide spread usage until the 1960s, when it was replaced by citrate-phosphate-dextrose (CPD) and citrate-phosphate-dextrose-adenine (CPDA) solutions that increased shelf life to 35 days and 42 days respectively. More recently, additive solutions containing saline, adenine, and dextrose have been developed to augment red cell survival following transfusion, although without any direct increase in storage duration. It is now well appreciated, however, that a number of morphologic and biochemical changes occur during red cell storage prior to product expiry, and these changes may hinder erythrocyte viability and function following transfusion. Despite a relatively large body of literature detailing the metabolic and structural deterioration that occurs during red cell storage, evidence for a significant detrimental clinical effect related to the transfusion of older blood is relatively less conclusive, limited primarily to observations in retrospective studies. Nonetheless, the implication that the transfusion of old, but not outdated blood may have negative clinical consequences demands attention. The purpose of this report is to describe the current understanding of the ...