Torres CM et al. JAMA Surg. Published online January 18, 2023. doi:10.1001/jamasurg.2022.6978
Trauma continues to be the leading cause of death in US civilians under 45 years of age.[i] Transfusion strategies to lessen morbidity and mortality caused by hemorrhage and trauma-induced coagulopathy (TIC) have been influenced by military success during wartime. The use of whole blood (WB) continues to increase among US adult trauma centers despite a paucity of civilian outcomes evidence, though this is changing rapidly. The single WB product is more rapidly administered compared with component therapy (red cells, platelets, and plasma). A recent study published in JAMA concludes that WB may also reduce the number of transfusions and donor exposure, and may improve survival and lessen the effects of TIC.
The purpose of this study was to examine the survival differences at 24 hours and 30 days in patients who received WB as part of a massive transfusion protocol (WB-MTP) compared to those who only received component therapy during MTP (MTP-only). MTP was defined as either a 1:1:1 ratio of RBC, plasma, and platelets, with a minimum of four RBC units within one hour of arrival in the emergency department, or 1:1:1 with at least ten RBC units within 24 hours of arrival. Secondary outcomes included length of stay and development of major complications such as pulmonary embolism, acute kidney injury, and stroke. This retrospective cohort study identified 2,785 adult patients from the American College of Surgeons Trauma Quality Improvement Program (ACS-TQIP) databank from January 1, 2017, to December 31, 2018. The cohort included 370 Level I and Level II trauma centers in the US and Canada. The final cohort was divided into 432 patients for the WB-MTP group and 2353 patients in the MTP-only group. Groups were similar in age, sex ratios, injury severity and other characteristics.
The article suggests that WB as part of an MTP is associated with improved survival at 24 hours and 30 days, without increased major complications (however, the study may not have been adequately powered to detect smaller differences).
The conclusion that transfusion of a median of one WB unit per patient in the WB-MTP arm demonstrated a survival benefit may seem puzzling, however the authors propose that it is indeed the effect of the WB unit correcting the TIC seen in the presenting trauma patient, especially within the first 5 hours, resulting in improved survival. Limitations include not knowing if blood products were given in the field prior to hospital arrival, and lack of access to data not routinely captured in the ACS-TQIP database (lactate, PT, PTT). As this was a retrospective database analysis, the authors stress that an association of improved survival (not causation) is suggested comparing WB-MTP versus MTP alone.
Ruby and colleagues recently published the results of a retrospective, single-center study of 1351 adult patients who received emergency-release, un-crossmatched blood products, and this study did not reach the same result. One group of 602 patients (22.9% categorized as trauma) were initially transfused RBCs, whereas 749 patients (23.2% categorized as trauma) initially received LTOWB[ii]. Patients from both groups may have also received component therapy after initial resuscitation with either RBC or LTOWB. In contrast, many centers’ MTP package includes RBC, plasma, and platelets; or LTOWB followed by component therapy. The study also defined a single LTOWB unit as one RBC, one plasma, and 0.17 platelet, rather than counting the product as a single unit. The groups were well-matched; however, severity injury scores were not shown. The authors stated that the RBC group received a smaller median total transfusion volume (and fewer total number of units transfused) within the first 24 hours and the first 7 days, compared with the LTOWB group. However, analyzing the subsets of patients from both groups who were massively transfused, defined as receiving 10 or more RBC units within 24 h after the initial release of emergency uncrossmatched blood, showed no difference in total blood volume transfused. Blood use specifically for trauma patients was not reported. Although the authors concluded that there was no difference in survival of trauma patients between the two groups at 24 hours or 30 days, supporting either approach of initial resuscitation with RBC or LTOWB, there were important gaps in study design, such as not adjusting the cohorts for injury severity to draw reliable conclusions.
Current prospective (randomized, parallel) studies enrolling patients include the Trauma Resuscitation with Low-Titer Group O Whole Blood or Products (TROOP) trial (https://clinicaltrials.gov/ct2/show/NCT05638581[iii]) and the Type O Whole Blood and Assessment of Age During Prehospital Resuscitation Trial (TOWAR) trial [iv](https://clinicaltrials.gov/ct2/show/NCT04684719). At this time, use of WB is not included by the ACS-TQIP 2014 massive transfusion in trauma guidelines as part of an MTP[v]. It is hoped that outcomes seen from these and other trials will help develop evidence-based approaches to trauma resuscitation for civilian settings.
The Red Cross offers cold-stored, low-titer, type O, leukocyte-reduced whole blood manufactured with a platelet-sparing filter. Please contact your regional ARC Medical Director and Account Representative for more information.
[i] https://www.aast.org/resources/trauma-facts#
[ii] (Ruby KN, 2023) Ruby KN, Dzik WH, et. Al. Emergency transfusion with whole blood versus packed red blood cells: A study of 1400 patients. 2023. Transfusion, 745-754.
[iii] https://clinicaltrials.gov/ct2/show/NCT05638581
[iv] https://clinicaltrials.gov/ct2/show/NCT04684719
[v] American College of Surgeons, ACS TQIP massive transfusion in trauma guidelines. Published October 2014.
