Researchers in JAMA Surgery have published a study that sought to explore whole blood transfusion timing and survival in trauma patients with severe hemorrhage. Specifically, the investigators aimed to, “analyze survival associated with whole blood (WB) transfusion timing among patients presenting with severe hemorrhage who received WB as an adjunct to massive transfusion protocol (MTP) in U.S. and Canadian adult civilian trauma centers over a two-year period.”
For this retrospective cohort study, the investigators conducted survival and secondary analyses of, “adult patients treated at level 1 and 2 U.S. and Canadian civilian trauma centers participating in the American College of Surgeons (ACS) Trauma Quality Improvement Program (TQIP) between January 2019 and December 2020.” Study participants included civilians over the age of 17, “presenting with severe hemorrhage who received WB and MTP within the first 24 hours of emergency department (ED) presentation. Severe hemorrhage was defined as systolic blood pressure less than 90 mm Hg, shock index greater than one, and receipt of MTP.” The authors noted that, “we chose these criteria to define severe hemorrhage, as the combination of a shock index greater than one and hypotension on ED arrival has been associated with trauma-induced coagulopathy (TIC), increased bleeding-related mortality, and the requisite for MTP. The MTP was defined as receiving a balanced ratio of packed red blood cells, plasma, and platelets of four or more units transfused within one hour from ED presentation up to four hours after ED arrival, as has been done in previous studies…All patients received WB as an adjunct to MTP.”
The authors stated that, “[t]he primary outcomes measured were survival time at 24 hours and 30 days. Secondary outcomes selected a priori were survival time at four hours, major complications, hospital length of stay (LOS), and intensive care unit (ICU) LOS…In total, 1,394 patients were identified [as meeting the study criteria] (239 female [17 percent]; 1,155 male [83 percent]; median age, 39 years [interquartile range (IQR), 25-51 years]…The overall 30-day mortality rate was 16 percent. The median time to first WB transfusion overall was 30 minutes (IQR, 6-31 minutes), and the median time to first product of MTP was 36 minutes (IQR, 9-37 minutes). Patients in the study were profoundly injured, with a median Injury Severity Score of 27 (IQR, 17-35). The median WB units transfused was two (IQR, 1-2 units), with 304 patients (22 percent) receiving more than two units of WB within four hours. The median hospital length of stay (LOS) was 20 days (IQR, 6-27 days). The median ICU LOS was 11 days (IQR, 3-15 days).”
The researchers explained that, “[w]e performed a survival analysis at 24 hours. A survival curve demon-strated a difference in survival within one hour of ED presentation and WB transfusion. There was an association between improved survival at 24 hours for earlier WB transfusion compared with later WB transfusion at each time point (adjusted HR, 0.40; 95 percent CI, 0.22-0.73; P = .003) Similarly, the ad-justed survival regression model demonstrated improved survival benefit associated with earlier WB transfusion at every time point at 30 days (adjusted HR, 0.32; 95 percent CI, 0.22-0.45; P < .001) Addi-tionally, the most pronounced reduction in the estimated probability of survival was found when the time to WB transfusion was after 14 minutes from 0.961 (95 percent CI, 0.855-1.067) at 14 minutes to 0.913 (95 percent CI, 0.806-1.020) at 15 minutes, with a risk difference of 5.7 percent (95 percent CI, 3.93-7.46 percent) at the following 15-minute time point. For the secondary outcome of survival at four hours, for every 1-minute increase in time to WB transfusion, there was an associated increase in risk of mortality (HR, 1.15; 95 percent CI, 1.07-1.25; P < .001).”
The study concluded that, “early receipt of WB at any time point within the first 24 hours of ED arrival was associated with improved survival in patients presenting with severe hemorrhage. The survival bene-fit was noted shortly after transfusion. Therefore, WB resuscitation given as soon as possible may pro-vide a survival advantage in actively hemorrhaging patients.” The authors added that, “[f]urther prospective studies are warranted to complement our results to incorporate these findings into MTPs and further understand best WB transfusion practices.” Limitations of the study identified by the researchers included, “the observed benefits were merely associated with the time to first WB transfusion and should not be interpreted as a direct cause. Since this study was observational and lacked randomization, there was an inherent risk of confounding factors due to clinical indications and other potentially unmeasured bias-es…Furthermore, our ability to consider the rate of specific ED procedures that could potentially lead to a delay of the initial WB transfusion in the later recipients was limited…Our study was subject to other certain database limitations, including the absence of laboratory data, practitioner-level data, and information on the administration of tranexamic acid…Finally, prehospital blood product transfusion is not specified in the TQIP data set.”
Citation: Torres, C., Kenzik, K., Saillant, N., et al. “Timing to first whole blood transfusion and survival following severe hemorrhage in trauma patients.” JAMA Surgery. 2024.