Microcirculation and blood transfusion: effects of three different types of concentrated red blood cells - preliminary results

Introduction

Red blood cell (RBC) transfusions are used to increase oxygen delivery; however, a restrictive transfusion strategy (predefined hemoglobin threshold of 7 g/dl) was demonstrated to be associated with lower mortality and incidence of nosocomial infections than a liberal one [1, 2]. This may be related to the storage process, which could affect the ability of RBCs to transport and delivery oxygen, or to immunomodulating effects of cytokines from residual leukocytes [2]. The aim of the study is to evaluate the effects, on microcirculation of septic patient, of three types of RBCs.

Methods

A controlled randomized prospective study on 45 patients with sepsis, severe sepsis or septic shock requiring RBC transfusion. Patients are randomized into three groups receiving: (1) fresh standard RBCs (storage <10 days); (2) leukodepleted RBCs; and (3) old standard RBCs (storage >20 days) respectively. Before and 1 hour after the transfusion, microcirculation is evaluated using sidestream dark-field imaging [3] and near-infrared spectroscopy with a vascular occlusion test. We also monitor temperature, heart rate, mean blood pressure, hemochrome, blood gases, blood lactates and SOFA score.

Results

Preliminary data on 18 patients, six for each group: before and after transfusion, in group 2, but not in groups 1 and 3, there is a trend to an increase in MFIs (P = 0.09), DeBacker score (Figure 1, P < 0.05), PPV (P = 0.07) and PVD (P = 0.07). No relevant differences for other parameters.

Figure 1

De Backer score pre and post transfusion in group 2.

Conclusion

After transfusion, microcirculation seems to be improved in the leukodepleted RBC group with a significant improvement of De Backer score and a trend to improve the other microcirculatory parameters, while in the other three groups there was not this trend.