Red blood cell transfusion and its effect on microvascular dysfunction in shock states

Area of Science:

• Physiology
• Transfusion Medicine
• Microcirculation Research

Background:

• Critically ill patients often receive red blood cell (RBC) transfusions for anemia without active bleeding.
• RBC transfusions may not improve outcomes due to impaired microcirculatory function.
• Stored RBCs undergo a 'storage lesion,' altering their structure and function.

Purpose of the Study:

• To review the current understanding of RBC nitric oxide (NO)-mediated vasodilation.
• To explore the dysfunctional interactions between stored RBCs and the microcirculation.
• To discuss findings from direct microcirculation observations before and after RBC transfusion.

Main Methods:

• Review of existing literature on RBC function, storage lesion, and microcirculation.
• Analysis of studies investigating NO-dependent vasodilation in RBCs.
• Examination of data from noninvasive human microcirculation observation technologies.

Main Results:

• Circulating RBCs normally facilitate oxygen delivery via NO-mediated vasodilation.
• The storage lesion impairs RBC function, potentially hindering NO-mediated vasodilation.
• Direct microcirculation observations provide insights into RBC transfusion effects.

Conclusions:

• Stored RBCs may have a diminished capacity to promote microcirculatory vasodilation.
• Understanding RBC-microcirculation interactions is crucial for optimizing transfusion strategies.
• Further research is needed to address the impact of the storage lesion on transfusion efficacy.