(P-TS-77) Low Titer O Whole Blood Transfusion for Life Threatening Gastrointestinal and Post-Partum Hemorrhage

Background/Case Studies: Low titer O whole blood (LTOWB) is often used in the management of trauma-related major hemorrhage. The use of LTOWB in non-trauma patients is less well studied. This study assessed the feasibility and safety of administering LTOWB to patients with non-trauma related major hemorrhage.

Study

Design/Methods: According to hospital protocol, patients at two large academic centers with life-threatening gastrointestinal bleeding (GIB) or post-partum hemorrhage (PPH) between December 2023 and April 2025 were eligible to receive uncrossmatched LTOWB (titer < 150). Pre-specified data were collected using a standardized collection form and included: demographic, clinical and baseline laboratory data, bleeding etiology, number of LTOWB units transfused, number and volume of additional blood components transfused, storage duration of the LTOWB units, and lactate dehydrogenase (LDH), total bilirubin, potassium and creatinine levels following LTOWB transfusion. Patients were stratified by group O versus non-group O and results compared using the student T test.

Results/Findings: 84 patients were included in the study, 38 men and 46 women with a median (IQR) age of 68 (46-77) years. Of the patients, 65/84 (77%) had GIB and 19/84 (23%) had PPH. Of the 84 patients, 29 (34.5%) were group O and 55 (65.5%) were non group O. A total of 144 units were transfused, 106 for GIB and 38 for PPH. The median (IQR) number of LTOWB units transfused to both Group O patients non Group O was 2 (1-4). LTOWB was the first product administered in 56/84 (66.7%) patients. The median (IQR) duration of storage of the LTOWB units was 17 (14-19) days. Hemolytic parameters among the group O versus non-group O patients within 24, 36 and 48 hour time periods are shown in Figure A. There were no significant differences between the groups for any parameter at any time point. No hemolytic transfusion reactions were reported. In hospital mortality (data available for 77 patients) was 22% for group O patients and 32% for non-group O patients (p=0.36).

Conclusions: LTOWB transfusion for life threatening GIB or PPH is feasible and appears to be safe in non-group O recipients. An ongoing multicenter clinical trial in this novel non-trauma patient population will provide data regarding the overall clinical utility of this practice change.