Unintentional injury is the leading cause of death in the United States among persons aged 1-44 years;”1” and trauma is an important driver of evidence-based medicine to reverse the lethal triad of hypocoagulation, hypothermia, and acidosis resulting from massive hemorrhage.”2“Many US adult trauma centers and some pediatric centers have adopted the use of low titer group O whole blood “LTOWB3“as data continues to bolster its use.
A recently published single-center observational study by Shea and colleagues“3“ compared outcomes including 24-hour survival, the primary outcome; organ dysfunction; and 72-hour total transfused blood product volume for 348 trauma patients who received either LTOWB or component therapy (CT). Patients were included if they were 18 years of age or older, their massive transfusion protocol was due to traumatic injury, they received at least one blood product, and they did not expire within 1 hour of arrival due to unsalvageable injury. The data was both retrospectively and prospectively obtained. The LTOWB arm had 168 trauma patients; the CT arm had 180 trauma patients. Patients receiving LTOWB received a maximum of 8 units per hospital policy, therefore some patients in this arm needing additional blood products received a combination of LTOWB and CT.
This study used LTOWB units collected by the American Red Cross from healthy, volunteer, type O positive blood donors. The units were stored in citrate phosphate dextrose solution (CPD), with anti-A and anti-B titers of less than 200. Units were leukoreduced using platelet-sparing filters and unit shelf life was 21 days. Units were cold-stored.”4“
Increased overall survival at 24 hours was seen in the LTOWB arm with 13 deaths of 168 patients (8%) compared to the CT group with 34 deaths among 180 patients (19%). Many other parameters were related to survival; but the ones most closely related were maximum clot firmness by ROTEM on admission (MCF), Glasgow Coma Scale score, and admission platelet count.
Importantly, patients diagnosed with shock, as defined by base excess, and who received LTOWB had increased survival at 24 hours and 28 days compared to CT patients. Patients with coagulopathy–as defined by increased PTT or PT, decreased platelet count, or decreased MCF–also had increased survival at those time points. This study also considered whether there were any differences in outcomes between group O and non–group O recipients of LTOWB. Although there were a few differences in baseline parameters, there were no differences in mortality at 6 hours, 24 hours, or 28 days or in maximum multiple organ dysfunction score (MODS) over 3 days.
CT patients received a median of 81 mL/kg of total blood products within the first 72 hours after admission. LTOWB patients received a median of 47 mL/kg. Thus, an LTOWB patient received on average about 30 mL/kg, or about 40%, less volume. The median patient weight was 80 kg, so each LTOWB patient received on average about 2.4 L less blood product volume.
In summary, in this study of adult trauma patients with massive transfusion protocol activations, LTOWB use, compared to CT use, was independently associated with improved 24-hour survival. Patients with shock or coagulopathy who received LTOWB also had improved 28-day survival. LTOWB use resulted in a 40% reduction in volume of blood products transfused per patient and thus reduced donor exposure. Randomized controlled trials may help elucidate and refine the knowledge regarding ideal volumes of LTOWB and patient populations that respond best to LTOWB.
1. 10 Leading Causes of Death, United States: 2020, Both sexes, All ages, All races [Internet]. Atlanta (GA): Centers for Disease Control and Prevention (US), National Center for Injury Prevention and Control; [cited 2024 Apr 26]. [about 2 screens]. Available from: https://www.cdc.gov/injury/wisqars/pdf/leading_causes_of_death_by_age_group_2020-508.pdf
2. Kashuk JL, Moore EE, Millikan JS, Moore JB. Major abdominal vascular trauma–a unified approach. J Trauma. 1982 Aug;22(8):672-9.
3. Shea SM, Mihalko EP, Lu L, Thomas KA, Schuerer D, Brown JB, Bochicchio GV, Spinella PC. Doing more with less: low-titer group O whole blood resulted in less total transfusions and an independent association with survival in adults with severe traumatic hemorrhage. J Thromb Haemost. 2023;22:140–51.
4. Low Titer O Whole Blood [Internet]. Washington (DC): American National Red Cross; c2024 [cited 2024 Apr 26]. [about 6 screens]. Available from: https://www.redcrossblood.org/biomedical-services/blood-products-and-services/low-titer-o-whole-blood.html
