Blood transfusions recruit the microcirculation during cardiac surgery

Area of Science:

• Cardiovascular Surgery
• Transfusion Medicine
• Microcirculation Research

Background:

• Perioperative red blood cell transfusions are common in cardiac surgery to manage anemia from blood loss and hemodilution.
• Cardiopulmonary bypass circulation contributes to anemia during these procedures.
• The study investigated the impact of transfusions on microcirculatory function.

Purpose of the Study:

• To test if blood transfusion beneficially affects sublingual microcirculatory density, perfusion, and oxygenation.
• To evaluate the microcirculatory response to transfusion in cardiac surgery patients.

Main Methods:

• A prospective, observational study included 24 adult patients undergoing on-pump cardiac surgery.
• Sidestream dark field (SDF) imaging assessed microcirculatory density and perfusion in 12 patients.
• Sublingual reflectance spectrophotometry monitored microcirculatory oxygenation and hemoglobin (Hb) concentration in 12 patients.

Main Results:

• Transfusion increased systemic Hb concentration and hematocrit.
• SDF imaging showed increased sublingual microcirculatory density (p < 0.01).
• Spectrophotometry revealed increased microcirculatory Hb content and improved microcirculatory Hb oxygen saturation (p = 0.06).

Conclusions:

• Blood transfusion enhances systemic oxygen-carrying capacity.
• Transfusion improves sublingual microcirculatory density, but not perfusion velocity.
• The study confirms improved microcirculatory oxygen saturation following transfusion.