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Use of whole blood (WB) combined with component therapy-based massive transfusion protocol (MTP) improved survival over MTP alone in patients with severe hemorrhage, a retrospective cohort study suggested.

Among nearly 2,800 patients with severe injuries, WB-MTP was associated with a lower risk of mortality at 24 hours (HR 0.63, 95% CI 0.41-0.96, P=0.03), reported Crisanto M. Torres, MD, MPH, of Boston University School of Medicine, and colleagues.

This benefit remained consistent at 30 days (HR 0.53, 95% CI 0.31-0.93, P=0.02), they noted in .

"Furthermore, the survival curves for the 2 groups separated within 5 hours of ED [emergency department] arrival and initial blood product transfusion, suggesting that WB is associated with an early beneficial effect in blunting the pathophysiology of TIC [trauma-induced coagulopathy]," Torres and team wrote. "The early favorable results associated with WB indicate the importance of timely administration in patients presenting with severe hemorrhage shortly after ED arrival."

Jason L. Sperry, MD, MPH, of the University of Pittsburgh in Pennsylvania, who was a co-author on an to the study, told 麻豆传媒 that this study "showed that whole blood was beneficial."

"It's like giving the full sandwich rather than giving bread, salami, and tomato, and a little mustard and mayo separately," he said. "It's just good to have the whole sandwich ... it's cleaner, it's less messy."

Torres and colleagues also analyzed secondary a priori outcomes, including major complications and length of stay in the hospital and in the intensive care unit (ICU). They found no significant differences between the groups for major in-hospital complications, such as deep venous thrombosis, pulmonary embolism, acute respiratory distress syndrome, stroke, and acute kidney injury (OR 0.82, 95% CI 0.37-1.81, P=0.63). The WB-MPT group did have significantly longer hospital lengths of stay (mean difference -1.67 days, 95% CI -2.80 to -0.53, P=0.004), but there was no difference between the two groups for lengths of stay in the ICU.

In a univariate analysis, patients who received WB-MTP had significantly improved survival at 24 hours (HR 0.72, 95% CI 0.52-0.99, P=0.049) and at 30 days (HR 0.74, 95% CI 0.59-0.95, P=0.02). After propensity score matching, the survival benefit associated with WB-MTP held at 24 hours (HR 0.76, 95% CI 0.62-0.95, P=0.02) and at 30 days (HR 0.48, 95% CI 0.25-0.91, P=0.03).

Historically, the U.S. military used whole blood to treat casualties, often collected nearby and used at points of wounding shortly afterward. Civilian blood banks slowly shifted away from the use of whole blood in favor of an increasing use of crystalloid fluids and fractionated blood components, partially because of concerns about infectious disease transmission.

"Once scientists learned [how] to fractionalize whole blood, this allowed physicians to provide separated blood components ... based on the patient's blood component deficiency," Torres wrote in an email to 麻豆传媒. "This allowed preservation of blood product. However, there was no evidence that this improved patient outcomes."

Recently, whole blood use is resurging, and may be more effective at correcting severe hemorrhagic shock and coagulopathy.

"It's become very popular," Sperry told 麻豆传媒, noting that up to 80 trauma centers across the country . In their commentary, Sperry and colleagues wrote that prospective randomized trials "that can definitively establish the efficacy and safety of early whole-blood resuscitation" are needed, and two trials and currently enrolling patients at risk for hemorrhagic shock.

"Our study helps to further define a population and definition of patients that would benefit from WB," Torres noted, adding that at his hospital, "any patient with severe hemorrhage are given whole blood immediately. However, not all centers carry whole blood."

"We predict whole-blood resuscitation will become the standard of care for severely injured patients with hemorrhagic shock," they concluded.

For this study, Torres and team used de-identified patient and hospital data from January 2017 through December 2018 in the American College of Surgeons Trauma Quality Improvement Program databank. The emergency departments included were either Level I or II trauma centers in the U.S. and Canada.

They included 2,785 adults with severe hemorrhage, defined by systolic blood pressure less than 90 mm Hg, a shock index greater than 1, and receipt of 4 units of packed red blood cells (pRBCs) within an hour of admission. All patients received MTP within 24 hours at the ED, defined as a 1:1:1 ratio of pRBCs, plasma, and platelets after at least 4 units of transfused pRBCs.

Of the 432 patients who received WB-MTP, median age was 38 and 78% were men, and of the 2,353 who received MTP only, median age was 38 and 77% were men. The median injury severity score was 28 (IQR 17-34). The overall 30-day mortality rate was 22%.

Limitations to the study included the lack of randomization, and the under- or overestimation of the benefits of whole blood due to confounding by indication, Torres and colleagues noted. In addition, the study lacked laboratory data, practitioner-level data, and data on tranexamic acid administration.

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