Transfusion of banked red blood cells and the effects on hemorrheology and microvascular hemodynamics in anemic hematology outpatients

BACKGROUND: The aim of this study was to investigate the effects of red blood cell (RBC) transfusion on the hemorrheologic properties and microcirculatory hemodynamics in anemic hematology outpatients receiving 2 to 4 RBC units of either fresh (leukoreduced storage for less than 1week) or aged (leukoreduced storage for 3-4 weeks) RBCs. STUDY DESIGN AND METHODS: Measurements were performed before and 30 minutes after RBC transfusion in hematology outpatients. Leukoreduced RBC suspensions were stored in saline-adenine-glucose-mannitol (SAGM) additive solution. Whole blood viscosity was measured using Couette low-shear viscometry, RBC deformability and aggregability were measured using laser-assisted optical rotational cell analysis, and microcirculatory density and perfusion were assessed using sidestream dark field imaging. RESULTS: One group of patients (n=10) received a median (interquartile range) of 3 (2-3) RBC bags that were stored for 7 (5-7) days (fresh) and the other group of patients (n=10) received 3 (3-3) RBC bags that were stored for 23 (22-28) days (aged). After transfusion of fresh versus aged RBCs, hematocrit increased to 32 +/- 3% versus 31 +/- 2% (p <0.363), whole blood viscosity increased to 4.2 +/- 0.4Pa/sec versus 4.2 +/- 0.6Pa/sec (p <0.912), RBC deformability index remained unaffected, RBC aggregability index increased to 55 +/- 10 versus 55 +/- 13 (p=0.967), microcirculatory flow remained unaffected, and microcirculatory density increased to 19.3 +/- 2.5mm/mm2 versus 18.7 +/- 1.9mm/mm2 (p=0.595), respectively. CONCLUSION: Storing leukoreduced SAGM-suspended RBCs for 3 to 4 weeks did not affect their ability to improve hemorrheologic properties and microcirculatory hemodynamics in our small group of anemic hematology outpatients. Larger studies are needed to confirm this finding