Monitoring Mitochondrial Oxygen Tension: mitoPO₂ as Physiologic Transfusion Trigger?

Hemoglobin-based red blood cell transfusion (RBC) triggers are inadequate for personalized transfusion decisions because they are population-based and therefore unable to identify individual patients that will benefit from RBC transfusion. Therefore, physiological transfusion triggers are sought after to provide tools for a more individualize approach. Since mitochondria are the ultimate destination of oxygen it seems reasonable to suggest that measuring oxygen at the mitochondrial level might provide insight in the need for RBC transfusion. Mitochondrial oxygen tension (mitoPO₂) is a novel clinical parameter that can be measured by an optical technology. This narrative review provides a brief introduction on mitoPO₂ monitoring and uses 5 recent studies to explore the potential of mitoPO₂ as tool for assessing need for transfusion and/or monitoring the effect of transfusion. A mathematical model shows an ideal behavior of mitoPO₂ on critical hematocrit and from 4 recent clinical studies we learn that mitoPO₂ is an independent parameter that can be used in transfusion-related studies. Further investigation into the potential role of mitoPO₂ in transfusion medicine is needed.