Low‐titer O whole‐blood transfusion for life‐threatening gastrointestinal and post‐partum hemorrhage

Background and Objectives Low‐titer O whole blood (LTOWB) is found to be associated with a survival advantage in trauma‐related major hemorrhage in some prospective studies. The role of LTOWB in non‐trauma patients has not been as extensively studied. In this study, we assess the feasibility and safety of administering LTOWB to patients with life‐threatening gastrointestinal bleeding (GIB) and post‐partum hemorrhage (PPH). Study Design and Methods We performed a retrospective study of patients who received LTOWB at a large regional academic center for life‐threatening GIB and PPH according to hospital protocol between 1 December 2023 and 31 December 2025. Demographic, clinical, transfusion, laboratory data, including hemolysis‐related variables, and clinical outcomes were compared between group‐O and non‐group‐O patients. Results We studied 112 patients, 53 men and 59 women, with a median (interquartile range [IQR]) age of 68 (41–77) years. Of these, 87/112 (77%) had GIB and 25/112 (23%) had PPH; 38/112 (34%) were group‐O and 74/112 (66%) non‐group‐O. In total, 203 LTOWB units were transfused, 155 for GIB and 48 for PPH. The median (IQR) number of LTOWB units transfused to both group‐O patients and non‐group‐O was 2 (1–2). There were no clinically significant laboratory or mortality differences between group‐O versus non‐group‐O patients, which was 3% versus 4% at 24 h, respectively. No hemolytic transfusion reactions were reported. Conclusion LTOWB transfusion for life‐threatening GIB or PPH is feasible and not associated with hemolysis in non‐group‐O recipients. Further studies are required to determine the clinical utility of this transfusion strategy.