Transfusion Considerations

One potential risk in administrating stored RBC concentrates is a transfusion reaction. Leukoreduction (LR; ie, removal of WBCs and platelets) before storage can help decrease risk. During storage, RBCs undergo progressive biochemical and biomechanical alterations that lead to the formation of microparticles (MPs), believed to be involved in the pathophysiology of transfusion reactions. In this study, whole blood was collected from 11 dogs; 6 units underwent prestorage LR, and 5 did not. Over 5 weeks, aliquots were collected from each unit and MP concentrations were measured by flow cytometry. At days 0 and 7, there was no difference between the treated and untreated stored blood. However, at days 14, 21, 28, and 35, mean MP counts increased 1.8-fold and 5.5-fold for treated and untreated blood, respectively.

CommentaryBlood transfusions are becoming more common as private practice develop emergency capabilities. Understanding the various blood products available and making qualitative assessments of which to choose is essential. Although most practitioners are familiar with basic blood typing and crossmatching, the minutiae of blood product storage complications (eg, transfusion-related acute lung injury) may not enter the psyche. This study concerned microparticles, which are the miniature breakdown products of RBCs that occur before collection and during storage as a result of interaction with WBCs. These MPs are implicated in several life-threatening transfusion complications. By applying a simple filtration technique to remove WBCs before storage, investigators were able to significantly reduce the number of MPs that would have formed during standard storage after 1 week, as compared with nonfiltered controls. It would be wise to consider preparation and storage of any commercially procured blood units before transfusing a critical patient. Review of other factors, including how blood products are delivered to the patient,¹ is recommended.—Ewan Wolff, DVM, PhD

SourceMicroparticles in stored canine RBC concentrates. Herring JM, Smith SA, McMichael MA, et al. VET CLIN PATHOL 42:163-169, 2013.

1. Influence of transfusion technique on survival of autologous red blood cells in the dog. McDevitt RI, Ruaux CG, Baltzer WI. JVECC 21:209-216, 2011.