Red blood cell transfusions (RBCTs) are life-saving treatments for critically ill patients suffering from anemia, a condition where the body lacks enough healthy red blood cells to deliver oxygen effectively. While effective in increasing oxygen levels in the blood, transfusions can disrupt blood flow and oxygen distribution, potentially causing harm to vital organs like the brain. To address this, researchers are exploring new tools to monitor these effects more precisely.
A recent study reported in Biophotonics Discovery investigated a novel technology called hybrid diffuse optics (DO), which uses near-infrared light to continuously measure changes in blood flow and oxygen levels noninvasively. The goal was to understand whether this technique could enhance decision-making and improve outcomes by providing detailed insights into how oxygen is delivered and utilized in the body. Unlike traditional methods that provide only systemic data (e.g., blood samples), this technology offers a detailed look at local changes in specific tissues.
The study monitored critically ill patients undergoing RBCTs in an intensive care unit. Optical probes placed on the patients' foreheads (to measure brain responses) and muscles (to measure peripheral responses) provided continuous data before, during, and after transfusions.
After transfusion, oxygen supply increased significantly in both the brain and muscles. This was confirmed by higher levels of oxygenated hemoglobin and total hemoglobin. Oxygen extraction fractions decreased in both the brain and peripheral muscles, indicating that tissues were better oxygenated. While the brain maintained stable blood flow, the muscles experienced a significant increase in blood flow after transfusion. This suggests that the brain had protective mechanisms at play to regulate oxygen supply. The study found no signs of harmful effects like over-perfusion (excess blood flow) or under-perfusion in the brain, highlighting the potential safety of RBCTs when guided by these advanced monitoring techniques.
This research demonstrates the potential of hybrid DO as a tool for optimizing blood transfusions, helping doctors tailor treatments to individual patients, minimizing risks and improving outcomes. For instance, doctors could use this tool to confirm that the brain is receiving enough oxygen without risking excessive blood flow to other areas, which might cause swelling or other complications. This study is a promising step toward integrating advanced optical tools into routine medical care, paving the way for safer and more effective treatments for critically ill patients.
The insights gained from this study could lead to:
- Personalized medicine. Real-time monitoring could guide more precise transfusion strategies, ensuring each patient gets exactly what they need.
- Improved decision-making. By identifying which tissues are under stress, clinicians can make more informed decisions about when to intervene.
- Wider adoption of noninvasive tools. The use of optical technologies could reduce reliance on invasive procedures, making critical care safer and more comfortable for patients.
Beyond critical care, this technology could have applications in surgery, neonatal care, neurocritical care, and managing chronic conditions.
For details, see the original Gold Open Access article by S. Tagliabue et al., " Hybrid diffuse optical appraisal of peripheral and cerebral changes in critically ill patients receiving red blood cell transfusion ," Biophotonics Discovery 2(1), 015001 (2025), doi: 10.1117/1.BIOS.2.1.015001
