Blood Transfusions and AKI following CABG: Does age of PRBCs matter?

Blood transfusions have been linked with risk of AKI following cardiac surgery. Anemia and number of PRBCs transfusion are independent risk factors for development of AKI post CABG, Catalytic iron can produce oxidative stress, surrogate for hypotension and a “sick patient” and age of PRBCs maybe the culprit? In addition, PRBCs have been linked with non renal adverse outcomes such as 16% increase risk of mortality post CABG, risk of sepsis and pneumonia and risk of increased length of intubation.

A recent study called RECESS trial just published in NEJM looked at the age of PRBCS and risk of outcomes following CABG. RECESS was a randomized trial at multiple sites from 2010 to 2014 looking at patients 12 years of age or older who had complex cardiac surgery and were likely to undergo transfusion of red cells were randomly assigned to receive leukocyte-reduced red cells stored for 10 days or less (shorter-term storage group) or for 21 days or more (longer-term storage group) for all intraoperative and postoperative transfusions.

The primary outcome was the change in Multiple Organ Dysfunction Score (MODS; range, 0 to 24, with higher scores indicating more severe organ dysfunction) from the preoperative score to the highest composite score through day 7 or the time of death or discharge.Overall results showed that the duration of PRBCS storage was not associated with MODS events. In addition, adverse events did not differ significantly between groups except that hyperbilirubinemia was more common in the longer-term storage group.

What about renal outcomes? In the supplementary sections, the renal outcomes are mentioned and there was no difference in both arms. Serious renal adverse events in both arms were also similar. So AKI risk might still exist due to PRBCs transfusion risk but it’s not due to the age of the PRBCS.