Does prolonged storage of red blood cells cause harm?

Area of Science:

• Transfusion Medicine
• Hematology

Background:

• Red blood cells (RBCs) undergo progressive degradation during refrigerated storage.
• Current definitions of 'fresh' versus 'old' RBCs are not universally standardized.
• Preservative solutions allow for extended RBC shelf lives, up to 7 weeks in some regions.

Purpose of the Study:

• To review the implications of red blood cell (RBC) storage duration on clinical outcomes.
• To discuss the challenges and ongoing research regarding the 'storage lesion' in transfused RBCs.
• To provide recommendations for blood collection and transfusion practices.

Main Methods:

• Review of existing literature, including observational studies, animal models, and volunteer studies.
• Analysis of a recent randomized controlled trial (RCT) in premature infants.
• Consideration of ongoing and planned RCTs.

Main Results:

• Evidence linking transfusion of stored RBCs, especially older units, to adverse clinical outcomes is controversial and contradictory.
• A recent RCT in premature infants highlighted the difficulties in moderately sized clinical studies.
• The impact of RBC storage may be clinically dependent and vary by setting.

Conclusions:

• The clinical significance of the RBC storage lesion requires further investigation, likely through large pragmatic clinical trials.
• Institutions should balance blood availability with strategies to minimize the use of the oldest stored RBCs.
• Further research is needed to establish optimal RBC storage and transfusion protocols.