Many studies have investigated the physiological, biochemical, and structural abnormalities that RBCs acquire during storage, but few have managed to compare oxygen delivery between “fresh” and “old” RBCs. In order to compare oxygen delivery of stored RBCs, researchers randomized (1:1:1) 30 healthy males (median age, 23 years) to receive two units of autologous RBCs either 7, 28, or 42 days after donation. In order to achieve comparable levels of anemia and keep the subjects blinded, subjects in the 7 and 42 days study arms donated two units of blood twice—two units at week 0 and two units at week 5—and were transfused with either 6-week old blood (42-day study arm) or one week old blood (7 day study arm). Subjects in the 28-day arm donated three units of RBCs over the study and were transfused with two units of 28 day old RBCs. Maximal oxygen uptake (VO2 max), the maximum rate of oxygen consumption and use during exercise, was measured two days before transfusion, immediately after transfusion, and two days after transfusion. As expected, hemoglobin levels decreased after blood donation by 2.8 g/dL and then increased after transfusion by 2.1 g/dL in all study arms. Furthermore, no differences in exercise duration (~5% increase in all arms, p=0.96) nor VO2 max (~10% increase in all arms, p=0.68) were observed between study arms indicating that storage time of RBCs did not affect oxygen delivery or consumption. The RBC storage lesion does not appear to have significant impact on oxygen delivery, but further studies in females, older individuals, and those with comorbidities are needed.
References:
- Bennett-Guerrero E, Rizwan S, Rozensky R, Romeiser JL, et al. Randomized controlled trial of 7, 28, vs 42 day stored red blood cell transfusion on oxygen delivery (VO2 max) and exercise duration. Transfusion 2021; 61: 699-707
- Dzik S. Blood stored for 42 days delivers oxygen as well as blood stored for 7 days. Transfusion 2021; 61: 657-659
