Microcirculation and blood transfusions during sepsis: leukoreduced (LR) versus non-LR red blood cells

Abstract

Introduction Microcirculatory alterations during sepsis impair tissue oxygenation, which may be further worsened by anemia. Blood transfusions proved not to restore O2 delivery during sepsis [1]. The impact of storage lesions and/or leukocyte-derived mediators in red blood cell (RBC) units has not yet been clarif ed [2]. We compared the effects of leukoreduced (LR) versus nonLR packed RBCs on microcirculation and tissue oxygenation during sepsis. Methods A prospective randomized study. Twenty patients with either sepsis, severe sepsis or septic shock requiring RBC transfusion randomly received nonLR (Group 1, n = 10) or LR (Group 2, n = 10) fresh RBCs (<10 days old). Before and 1 hour after transfusion, microvascular (GRAPH PRESENTED) density and flow were assessed with sidestream dark-field imaging sublingually. Thenar tissue O2 saturation (StO2) was measured using near-infrared spectroscopy and a vascular occlusion test was performed. Results The De Backer score (P = 0.02), total vessel density (P = 0.08), perfused vessel density (P = 0.04), proportion of perfused vessels (P = 0.01), and microvascular flow index (P = 0.04, Figure 1) increased only in Group 2. The StO2 upslope (Figure 2) during reperfusion increased in both groups (P <0.05). In Group 1 the baseline StO2 and StO2 downslope during ischemia increased, probably reffecting a lower 02 consumption. Conclusion Unlike nonLR RBCs, the transfusion of fresh LR RBCs seems to improve microvascular perfusion and might help to restore tissue oxygenation during sepsis.