Evaluation of Alternative Transfusion Triggers in Hemodynamically Stable, Non-Ventilated Cancer Patients

This is a prospective, single-center observational study conducted at the Kazakh Institute of Oncology and Radiology. The study included 107 clinically stable adult patients with cancer who required red blood cell transfusion based on a restrictive hemoglobin threshold. The aim of the study was to evaluate alternative physiological indicators of transfusion need and effectiveness. Measurements included oxygen extraction ratio (O₂ER), central venous oxygen saturation (ScvO₂), partial pressure of oxygen in central venous blood (PvO₂), arterio-venous oxygen difference (A-VO₂diff), lactate, and veno-arterial carbon dioxide difference (ΔCO₂). These parameters were assessed before and one hour after transfusion. For data analysis, patients were stratified into two groups based on their baseline O₂ER (≤35.4% and >35.4%) to evaluate whether higher O₂ER is associated with more pronounced physiological response to transfusion.