HILE THE EXACT BIOLOGIcal cascade associated with Alzheimer disease (AD) is only partially understood, many potential biomarkers of this disease process are known. 1 Two of the most obvious candidates are ␤-amyloid 1-42 and tau proteins, as they are intimately related to the pathognomonic features of amyloid plaques and neurofibrillary tangles in the AD brain. 2,3 Multiple previous studies have reported decreases in cerebrospinal fluid (CSF) measures of ␤-amyloid. 4-7 Similarly, CSF measures of tau have routinely showed considerable elevations of this peptide in AD cases worldwide. 7-12 Some authors have reported that these 2 measures alone can accurately differentiate clinically diagnosed AD cases from controls more than 85% of the time. 7,13 Studies of CSF in AD patients have used widely varying methods and nomenclature for assessing and describ-Author Affiliations are listed at the end of this article.

BACKGROUND: Use of whole blood (WB) for trauma resuscitation has seen a resurgence. The purpose of this study was to investigate survival benefit of WB across a diverse population of bleeding trauma patients. STUDY DESIGN: A prospective observational cohort study of injured patients receiving emergency-release blood products was performed. All adult trauma patients resuscitated between November 2017 and September 2020 were included. The WB group included patients receiving any group O WB units. The component (COMP) group received no WB units, instead relying on fractionated blood (red blood cells, plasma, and platelets). Univariate and multivariate analyses were performed. Given large observed differences in our regression model, post hoc adjustments with inverse probability of treatment were conducted and a propensity score created. Propensity scoring and Poisson regression supported these findings. RESULTS: Of 1,377 patients receiving emergency release blood products, 840 received WB and 537 remained in the COMP arm. WB patients had higher Injury Severity Score (ISS; 27 vs 20), lower field blood pressure (103 vs 114), and higher arrival lactate (4.2 vs 3.5; all p < 0.05). Postarrival transfusions and complications were similar between groups, except for sepsis, which was lower in the WB arm (25 vs 30%, p = 0.041). Although univariate analysis noted similar survival between WB and COMP (75 vs 76%), logistic regression found WB was independently associated with a 4-fold increased survival (odds ratio [OR] 4.10, p < 0.001). WB patients also had a 60% reduction in overall transfusions (OR 0.38, 95% CI 0.21-0.70). This impact on survival remained regardless of location of transfusion, ISS, or presence of head injury. CONCLUSION: In patients experiencing hemorrhagic shock, WB transfusion is associated with both improved survival and decreased overall blood utilization.