Blood transfusion in the critically ill: does storage age matter?

Area of Science:

• Hematology
• Transfusion Medicine
• Biochemistry

Background:

• Red blood cell (RBC) storage leads to morphologic and biochemical changes, collectively termed the 'storage lesion.'
• Historically, anticoagulant solutions like acid-citrate-dextrose (ACD), citrate-phosphate-dextrose (CPD), and citrate-phosphate-dextrose-adenine (CPDA) have extended blood shelf life.
• Modern additive solutions aim to improve post-transfusion RBC survival without increasing storage duration.

Purpose of the Study:

• To describe the biochemical and structural changes in stored RBCs (the storage lesion).
• To critically review the clinical evidence linking older RBC transfusion to detrimental outcomes.

Main Methods:

• Literature review of studies on RBC storage lesions.
• Critical analysis of clinical evidence regarding the transfusion of older RBCs.

Main Results:

• A significant body of literature details RBC metabolic and structural deterioration during storage.
• Clinical evidence for detrimental effects of transfusing older RBCs is largely based on retrospective studies.
• Most studies evaluated patients receiving mixed-age RBC units, complicating definitive conclusions.

Conclusions:

• The transfusion of older, but not outdated, RBCs may have negative clinical consequences.
• Current evidence is primarily from retrospective studies, limiting definitive conclusions.
• Prospective studies are needed to confirm findings and inform potential changes in transfusion practices regarding storage age.