Randomized controlled trial of 7, 28, vs 42 day stored red blood cell transfusion on oxygen delivery (VO₂ max) and exercise duration

Abstract

Background: Few studies have rigorously assessed the impact of red blood cell (RBC) transfusion on oxygen delivery. Several large trials demonstrated no clinical outcome differences between transfusion of shorter-storage vs prolonged-storage RBCs. These trials did not directly assess functional measures of oxygen delivery. Therefore, it is not clear if 42-day stored RBCs deliver oxygen as effectively as 7-day stored RBCs. Study Design and Methods: Leukocyte-reduced RBCs were collected by apheresis in AS-3. Thirty subjects were randomized (1:1:1) to receive 2 units of autologous RBCs at either 7, 28, or 42 days following donation. VO 2 max testing, using a standardized protocol to exhaustion, was performed 2 days before (Monday) and 2 days after (Friday) the transfusion visit (Wednesday). The primary endpoint was the percent increase in VO 2 max between Monday and Friday. The secondary endpoint was the percent change in duration of exercise for the same time points. Results: Hemoglobin levels decreased by 2.8 ± 1.4 g/dL after donation and increased by 2.1 ± 0.6 g/dL after transfusion. This change in hemoglobin was associated with expected decreases (then increases after transfusion) in VO 2 max and exercise duration. No differences were observed between 7-day and 42-day RBC transfusion for percent increase in median [IQR] VO 2 max (10.5

Effects of high-intensity interval training with hyperbaric oxygen

“…After institutional review board (IRB) approval and written informed consent, healthy non-smoker volunteers, ages 18 to 35 years, were screened. Subjects were excluded who had chronic comorbidities, pregnancy, sickle cell heterozygosity (African-American candidates were screened), physical deconditioning (sea-level V_O 2 peak below 35 mL.kg -1 .min -1 for men or 30 mL.kg -1 .min -1 for women) (Gill et al, 2014;Bennett-Guerrero et al, 2017;Bennett-Guerrero et al, 2021), or were unable to provide written informed consent in English.…”

Transfusion of red blood cells ≥35 days old: A narrative review of clinical outcomes

“…Alternative methods have estimated safety and effectiveness near expiration. Autotransfusion of 42‐day‐old RBCs suggests some quality markers are worsened (i.e., extravascular hemolysis, non‐transferrin‐bound iron,and in vivo recovery) while others are unaffected (i.e., intravascular hemolysis, oxygenation, microcirculation, and exercise duration) 7–9 . Most markers are not tied to FDA regulations and clinical relevance is not well established: autotransfusion of healthy volunteers is an imperfect surrogate for allogenic transfusion of ill patients.…”

Blood stored for 42 days delivers oxygen as well as blood stored for 7 days

“…In this issue of TRANSFUSION, Elliott Bennett-Guerrero and colleagues report a very carefully performed human physiology experiment testing whether red blood cell units (RBCs) stored for 42 days support intense aerobic human activity as well as RBCs stored for only 7 days. 3 In a study of 30 physically fit men who exercised to exhaustion, the investigators conducted detailed measurements of the maximum rate of oxygen consumption (VO 2 max) and exercise duration using a laboratory cycle ergometer. The experimental technique is well established.…”