Red blood cell (RBC) arteriovenous gap as a marker of hemotransfusion in massive and fulminant hemorrhage with the formation of Multiple Organ Dysfunction Syndrome (MODS). Case report

Background: Massive and fulminant hemorrhage frequently leads to critical states such as hemorrhagic shock and Multiple Organ Dysfunction Syndrome (MODS). Early diagnostic and therapeutic decision-making, particularly regarding hemotransfusion, remains a challenge when classical venous indicators do not reflect the severity of hypoxia. This study proposes the arteriovenous red blood cell (RBC) gap and pCO₂ arteriovenous (AV) gap as novel biomarkers for evaluating tissue hypoxia and guiding red blood cell transfusion, especially in cases with visual blood loss exceeding 3 liters. Materials and Methods: This case-based investigation evaluated the diagnostic utility of the RBC arteriovenous gap and the pCO₂ AV gap (>6 mmHg) as markers of Microcirculatory-Mitochondrial Distress Syndrome (MMDS), a precursor of MODS. Analysis included sequential arterial and venous blood gas measurements, lactate monitoring, and oxygenation indices in a patient presenting with severe hemorrhage and signs of MODS. The microcirculatory-mitochondrial recruitment strategy was applied, involving volemic resuscitation, oxygenation correction, and targeted hemotransfusion. Results: Initial measurements revealed a pCO₂ AV gap of 49.7 mmHg, confirming severe tissue hypoxia and MMDS. This gap decreased to 10.2 mmHg following the recruitment strategy, coinciding with the normalization of pH (6.9 → 7.4), improved oxygenation (SO₂ 51% → 98%), and decreased lactate levels (8.2 → 1.8 mmol/L). Despite a normal venous hematocrit (VHct 36%) and hemoglobin (VtHb 12.3 g/dL), arterial samples showed critical reductions (AHct <12%), justifying RBC transfusion. This AV discrepancy provided a reliable medico-legal basis for intervention, which traditional venous markers alone would not have supported. Conclusion: The RBC and pCO₂ AV gaps are effective, underutilized markers for detecting MMDS and guiding hemotransfusion in cases of massive hemorrhage. They reflect systemic hypoxia more accurately than isolated venous parameters. The application of microcirculatory-mitochondrial recruitment strategies improves patient outcomes and supports metabolic recovery, offering a low-tech yet life-saving intervention approach. These findings propose a paradigm shift in intensive care resuscitation strategies and transfusion criteria in critical care.