Whole truths but half the blood: Addressing the gap between the evidence and practice of pre-hospital and in-hospital blood product use for trauma resuscitation

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

BACKGROUND

Low-titer group O whole blood (LTOWB) or component therapy (CT) may be used to resuscitate hemorrhaging trauma patients. LTOWB may have clinical and logistical benefits and may improve survival.

OBJECTIVES

We hypothesized LTOWB would improve 24-hour survival in hemorrhaging patients and would be safe and equally efficacious in non-group O compared with group O patients.

METHODS

Adult trauma patients with massive transfusion protocol activations were enrolled in this observational study. The primary outcome was 24-hour mortality. Secondary outcomes included 72-hour total blood product use. A Cox regression determined the independent associations with 24-hour mortality.

RESULTS

In total, 348 patients were included (CT, n = 180; LTOWB, n = 168). Demographics were similar between cohorts. Unadjusted 24-hour mortality was reduced in LTOWB vs CT: 8% vs 19% (P = .003), but 6-hour and 28-day mortality were similar. In an adjusted analysis with multivariable Cox regression, LTOWB was independently associated with reduced 24-hour mortality (hazard ratio, 0.21; 95% CI, 0.07-0.67; P = .004). LTOWB patients received significantly less 72-hour total blood products (80.9 [41.6-139.3] mL/kg vs 48.9 [25.9-106.9] mL/kg; P < .001). In stratified 24-hour survival analyses, LTOWB was associated with improved survival for patients in shock or with coagulopathy. LTOWB use in non-group O patients was not associated with increased mortality, organ injury, or adverse events.

CONCLUSION

In this hypothesis-generating study, LTOWB use was independently associated with improved 24-hour survival, predominantly in patients with shock or coagulopathy. LTOWB also resulted in a 40% reduction in blood product use which equates to a median 2.4 L reduction in transfused products.

Is Low-Titer Group O Whole Blood Truly a Universal Blood Product?

BACKGROUND

Whole blood was historically transfused as a type-specific product. Given recent advocacy for low-titer group O whole blood (LTOWB) as a universal blood product, we examined outcomes after LTOWB transfusion stratified by recipient blood groups.

STUDY DESIGN

Adult trauma patients receiving prehospital or in-hospital transfusion of LTOWB (November 2017 to July 2020) at a single trauma center were prospectively evaluated. The patients were divided into blood type groups (O, A, B, and AB). Major complications and survival to 30 days were compared. Univariate analyses among blood groups were followed by purposeful regression modeling, reflecting 6 variables of significance: male sex, White race, injury severity, arrival lactate, arrival systolic blood pressure, and emergency department blood products.

RESULTS

Of 1,075 patients receiving any LTOWB, 539 (50.1%) were Group O, 340 (31.6%) were Group A, 150 (14.0%) were Group B, and 46 (4.3%) were Group AB. There were no statistically significant differences in demographics, injury severity, hemolysis panels, prehospital vitals, or resuscitation parameters (all p > 0.05). However, arrival systolic pressure was lower (91 vs 102, p = 0.034) and lactate was worse (5.5 vs 4.1, p = 0.048) in Group B patients compared to other groups. While survival and most major complications did not differ across recipient groups, acute kidney injury (AKI) initially appeared higher for Group B. Stepwise regression did not show a difference in AKI rates. This analysis was repeated in patients receiving only component products. Group B again showed no significantly increased risk of AKI (13%) compared to other groups (O 7%, A 7%, AB 5%; p = 0.091).

CONCLUSIONS

LTOWB appears to be a safe product for universal use across all blood groups. Group B recipients arrived with worse physiologic values associated with hemorrhagic shock whether receiving LTOWB or standard component products.

Resuscitation with whole blood or blood components improves survival and lessens the pathophysiological burden of trauma and haemorrhagic shock in a pre-clinical porcine model

PURPOSE

In military trauma, disaster medicine, and casualties injured in remote locations, times to advanced medical and surgical treatment are often prolonged, potentially reducing survival and increasing morbidity. Since resuscitation with blood/blood components improves survival over short pre-surgical times, this study aimed to evaluate the quality of resuscitation afforded by blood/blood products or crystalloid resuscitation over extended 'pre-hospital' timelines in a porcine model of militarily relevant traumatic haemorrhagic shock.

METHODS

This study underwent local ethical review and was done under the authority of Animals (Scientific Procedures) Act 1986. Forty-five terminally anaesthetised pigs received a soft tissue injury to the right thigh, haemorrhage (30% blood volume and a Grade IV liver injury) and fluid resuscitation initiated 30 min later [Group 1 (no fluid); 2 (0.9% saline); 3 (1:1 packed red blood cells:plasma); 4 (fresh whole blood); or 5 (plasma)]. Fluid (3 ml/kg bolus) was administered during the resuscitation period (maximum duration 450 min) when the systolic blood pressure fell below 80 mmHg. Surviving animals were culled with an overdose of anaesthetic.

RESULTS

Survival time was significantly shorter for Group 1 compared to the other groups (P < 0.05). Despite the same triggers for resuscitation when compared to blood/blood components, saline was associated with a shorter survival time (P = 0.145), greater pathophysiological burden and significantly greater resuscitation fluid volume (P < 0.0001).

CONCLUSION

When times to advanced medical care are prolonged, resuscitation with blood/blood components is recommended over saline due to the superior quality and stability of resuscitation achieved, which are likely to lead to improved patient outcomes.

The publication impact of the first 100 THOR Network publications by bibliometric and social network analyses

BACKGROUND

A specialized international multidisciplinary group of investigators wanted to determine the performance and impact of publications presented at an annual conference over a 6 year period. Specifically, the group wanted to know if the influence of the conference publications extended beyond conference publication authors and attendees. Bibliometric methods and network analyses were used to evaluate the performance and impact of 100 peer-reviewed publications presented at the Trauma Hemostasis and Oxygenation Research (THOR) Network Remote Damage Control Resuscitation (RCDR) Symposia from 2012 to 2017 (published 2013-2018). Further analysis was performed on the affiliations of conference attendees who attended from the years of 2012 to 2017.

STUDY DESIGN AND METHODS

This project used normative and relative bibliometric measures and social network analysis to evaluate the performance and impact of 100 peer-reviewed publications presented at the Trauma Hemostasis and Oxygenation Research (THOR) Network RDCR Symposia from 2012 to 2017. Publication and citation data were from Elsevier Scopus, a bibliographic citation database. Metrics from Elsevier SciVal were selected for the project to normalize for group size, year of publication, and document type. A six-year period of publications presented at the Symposia, published from 2013 to 2018, was selected for analysis. The publication and citation data were further analyzed using Elsevier SciVal and the iCite database from the National Institutes of Health Office of Portfolio Analysis. Sci2, VOSviewer, and Gephi were used for social network analyses and visualization.

RESULTS

The 100 publications presented at the Trauma Hemostasis and Oxygenation Research (THOR) Network Remote Damage Control Resuscitation (RCDR) Symposia from 2012 to 2017 demonstrate reach and influence beyond the authors of the THOR publications or the THOR attendees. Citations to the THOR publications were published in 10 languages and 313 unique journals, with author affiliations from 62 countries. Citation metrics for the THOR publications exceed global averages with 65% of the THOR publications being in the 25% citation percentiles. When benchmarking the THOR publications using six homogenous comparator groups, the THOR publications demonstrate higher citation metrics than any of the comparator groups with more citations per publication, a higher average of cited publications, higher FWCI and outputs in the top citation percentiles among the six groups. The Office of Portfolio Analysis (OPA) iCite database was used to calculate potential to translate for the THOR publications with 57 of the THOR publications cited by clinical articles with an average approximate potential to translate score of 65.3%.

CONCLUSIONS

The value of international groups with sharing of research and knowledge are instrumental in enhancing the uptake for best practices for in medicine and treatment of hemorrhagic shock resuscitation. The use of bibliometric methods and network analyses, along with benchmarking, demonstrated reach and impact beyond the THOR Network. Limitations include use of a single source for analysis of publication and citation; and that publication data alone does not provide a full overview of research performance. Despite these limitations, bibliometric methods, social network analyses, and benchmarking can help centers better understand their impact.

Nationwide estimates of the need for prehospital blood products after injury

INTRODUCTION

Prehospital blood product resuscitation after injury significantly decreases risk of mortality. However, the number of patients who may potentially benefit from this life-saving intervention is currently unknown. The primary objective of this study was to estimate the number of patients who may potentially benefit from prehospital blood product resuscitation after injury in the United States. The secondary objective was to estimate the amount of blood products needed for prehospital resuscitation of injured patients.

METHODS

Patients ≥16 years with blunt/penetrating injuries included in National Emergency Medical Services Information System 2019 were identified and classified into four separate cohorts of hemodynamic instability: Cohort 1 (systolic blood pressure [SBP] <90 mmHg), Cohort 2 (SBP <90 and/or heart rate [HR] >120), Cohort 3 (SBP <90 and HR >108 or SBP <70), and Cohort 4 (shock index ≥1). The need for prehospital blood was estimated by multiplying number of patients in each cohort with average number of blood products used for prehospital resuscitation.

RESULTS

After exclusions, 3.7 million adult trauma patients were included. The number of patients who may potentially benefit from prehospital blood products was estimated as 89,391 (Cohort 1), 901,346 (Cohort 2), 54,160 (Cohort 3), and 300,475 (Cohort 4). Assuming 1 unit of whole blood is needed per patient, a lower-bound estimate of 54,160 additional whole blood units (0.6% of current collections) will be need for prehospital resuscitation of the injured.

CONCLUSIONS

Annually, between 54,000 and 900,000 patients may potentially benefit from prehospital blood product resuscitation after injury in the United States. Prehospital blood utilization and collection of blood products will need to be increased to scale-up this life-saving intervention nationwide.

Emergency Blood Transfusion for Trauma and Perioperative Resuscitation: Standard of Care

Uncontrolled and massive bleeding with derangement of coagulation is a major challenge in the management of both surgical and seriously injured patients. The underlying mechanism of trauma-induced or -associated coagulopathy is tissue injury in the presence of shock and acidosis provoking endothelial damage, activation of inflammation, and coagulation disbalancing. Furthermore, the combination of ongoing blood loss and consumption of blood components that are essential for effective coagulation worsens uncontrolled hemorrhage. Additionally, therapeutic actions, such as resuscitation with replacement fluids or allogeneic blood products, can further aggravate coagulopathy. Of the coagulation factors essential to the clotting process, fibrinogen is the first to be consumed to critical levels during acute bleeding and current evidence suggests that normalizing fibrinogen levels in bleeding patients improves clot formation and clot strength, thereby controlling hemorrhage. Three different therapeutic approaches are discussed controversially. Whole blood transfusion is used especially in the military scenario and is also becoming more and more popular in the civilian world, although it is accompanied by a strong lack of evidence and severe safety issues. Transfusion of allogeneic blood concentrates in fixed ratios without any targets has been investigated extensively with disappointing results. Individualized and target-controlled coagulation management based on point-of-care diagnostics with respect to the huge heterogeneity of massive bleeding situations is an alternative and advanced approach to managing coagulopathy associated with massive bleeding in the trauma as well as the perioperative setting.

Hemorrhagic Resuscitation Guided by Viscoelastography in Far-Forward Combat and Austere Civilian Environments: Goal-Directed Whole-Blood and Blood-Component Therapy Far from the Trauma Center

Modern approaches to resuscitation seek to bring patient interventions as close as possible to the initial trauma. In recent decades, fresh or cold-stored whole blood has gained widespread support in multiple settings as the best first agent in resuscitation after massive blood loss. However, whole blood is not a panacea, and while current guidelines promote continued resuscitation with fixed ratios of blood products, the debate about the optimal resuscitation strategy-especially in austere or challenging environments-is by no means settled. In this narrative review, we give a brief history of military resuscitation and how whole blood became the mainstay of initial resuscitation. We then outline the principles of viscoelastic hemostatic assays as well as their adoption for providing goal-directed blood-component therapy in trauma centers. After summarizing the nascent research on the strengths and limitations of viscoelastic platforms in challenging environmental conditions, we conclude with our vision of how these platforms can be deployed in far-forward combat and austere civilian environments to maximize survival.