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 1 week) 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 ± 0.4 Pa/sec versus 4.2 ± 0.6 Pa/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 ± 2.5 mm/mm² versus 18.7 ± 1.9 mm/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.