Matthew D. Landrigan

Metabolomics evaluation of early-storage red blood cell rejuvenation at 4°C and 37°C: METABOLIC EFFECTS OF EARLY STORAGE RBC REJUVENATION

Refrigerated red blood cell (RBC) storage results in the progressive accumulation of biochemical and morphological alterations collectively referred to as the storage lesion. Storage‐induced metabolic alterations can be in part reversed by rejuvenation practices. However, rejuvenation requires an incubation step of RBCs for 1 hour at 37°C, limiting the practicality of providing “on‐demand,” rejuvenated RBCs. We tested the hypothesis that the addition of rejuvenation solution early in storage as an adjunct additive solution would prevent—in a time window consistent with the average age of units transfused to sickle cell recipients at Duke (15 days)—many of the adverse biochemical changes that can be reversed via standard rejuvenation, while obviating the incubation step.

Estimation of Achievable Oxygen Consumption Following Transfusion With Rejuvenated Red Blood Cells

Erythrocyte storage induces a nonphysiological increase in hemoglobin-oxygen affinity (quantified by low p50, the oxygen tension at 50% hemoglobin saturation), which can be restored through biochemical rejuvenation. The objective was to mathematically model the impact of transfusing up to 3 standard allogeneic units or rejuvenated units on oxygen delivery (DO2) and oxygen consumption (VO2). Oxygen dissociation curves were generated from additive solution-1 red blood cell (RBC) leukoreduced units (n = 7) before and after rejuvenation following manufacturers instructions. Two of these units were used to prepare standard or rejuvenated donor RBC and added to samples of fresh whole blood. These admixtures were used to construct an in vitro transfusion model of postoperative anemia and determine a linear equation for calculating the sample p50, which was subsequently used to calculate DO2 and VO2 after simulated transfusions. Whole blood-packed red blood cell unit admixture p50s could be predicted from a linear model including the p50 of its components, the mass fraction of the transfused component, and interaction terms (R2 = .99, P < 0.001). Transfusion with standard units slightly, but significantly, increased projected DO2 compared with rejuvenated units (P = 0.03), but rejuvenated units markedly increased projected VO2 (P = 0.03). Standard units did not significantly change VO2 relative to pre-transfusion levels (P > 0.1). Using high-p50, rejuvenated RBC in simulated transfusions greatly improved projected VO2, indicating the potential for increased end-organ oxygen availability compared with standard transfusion. Patient capacity to increase cardiac output after cardiac surgery may be limited. Transfusing high-p50 RBC in this setting may improve the perioperative care of these patients.