Pro-Con Debate: Prehospital Blood Transfusion-Should It Be Adopted for Civilian Trauma?

[Prehospital blood transfusion : Opportunities and challenges for the German emergency medical services]

BACKGROUND

Exsanguination is the leading cause of preventable death in severe trauma. Immediate hemorrhage control and transfusion of blood products are critical to maintain oxygen delivery and address trauma-induced coagulopathy. While prehospital blood product transfusion (PHBT) is established in neighboring countries, the fragmented configuration of Germany's emergency medical service (EMS) infrastructure has delayed the adoption of widespread PHBT programmes. This review aims to provide an updated perspective on the evolution, international practices and research needs of PHBT within the German context.

METHODS

This narrative review is based on a PubMed search using the search terms "prehospital" and "blood*". From an initial 4738 articles, 333 were directly related to PHBT and were subjected to further detailed examination. The literature, including referenced studies, was categorized into areas such as history, rationale, international practices, and evidence, and analyzed for quality.

RESULTS

The benefit of early blood transfusion in major trauma has been established since WW1, explaining the efforts to initiate this lifesaving intervention as early as possible in the care pathway, including the prehospital field. Recent randomized trials have faced design and recruitment challenges, reflecting the complexity of the research question. These trials have yielded inconclusive results regarding the survival benefits of PHBT in civilian settings. This scenario raises doubts about the capability of randomized trials to resolve questions concerning survival advantages. Despite these difficulties, there is a discernible trend indicating potential improvements in patient outcomes. In Germany, the incidence of trauma-associated shock stands at 38 per 100,000 individuals per year. It is estimated that between 300 and 1800 patients annually possibly benefit from PHBT.

CONCLUSION

Prehospital Blood Transfusion appears to be promising but identifying patient groups most likely to benefit as well as the most suitable blood products remain unresolved issues. In Germany PHBT programs are not yet widely established. Paradoxically, this situation, paired with the extensive German Trauma Registry, provides a prime opportunity for comprehensive prospective cohort studies, addressing the balance between PHBT benefits, logistical feasibility, and implementation strategies. Such studies are essential for establishing guidelines and integrating PHBT efficiently into German trauma care protocols.

Management Considerations for Air Medical Transport Programs Transfusing RhD-Positive Red Blood Cell-Containing Products to Females of Childbearing Potential

Recent years have seen increased discussion surrounding the benefits of damage control resuscitation, prehospital transfusion (PHT) of blood products, and the use of whole blood over component therapy. Concurrent shortages of blood products with the desire to provide PHT during air medical transport have prompted reconsideration of the traditional approach of administering RhD-negative red cell-containing blood products first-line to females of childbearing potential (FCPs). Given that only 7% of the US population has blood type O negative and 38% has O positive, some programs may be limited to offering RhD-positive blood products to FCPs. Adopting the practice of giving RhD-positive blood products first-line to FCPs extends the benefits of PHT to such patients, but this practice does incur the risk of future hemolytic disease of the fetus and newborn (HDFN). Although the risk of future fetal mortality after an RhD-incompatible transfusion is estimated to be low in the setting of acute hemorrhage, the number of FCPs who are affected by this disease will increase as more air medical transport programs adopt this practice. The process of monitoring and managing HDFN can also be time intensive and costly regardless of the rates of fetal mortality. Air medical transport programs planning on performing PHT of RhD-positive red cell-containing products to FCPs should have a basic understanding of the pathophysiology, prevention, and management of hemolytic disease of the newborn before introducing this practice. Programs should additionally ensure there is a reliable process to notify receiving centers of potentially RhD-incompatible PHT because alloimmunization prophylaxis is time sensitive. Facilities receiving patients who have had PHT must be prepared to identify, counsel, and offer alloimmunization prophylaxis to these patients. This review aims to provide air medical transport professionals with an understanding of the pathophysiology and management of HDFN and provide a template for the early management of FCPs who have received an RhD-positive red cell-containing PHT. This review also covers the initial workup and long-term anticipatory guidance that receiving trauma centers must provide to FCPs who have received RhD-positive red cell-containing PHT.

An Analysis of the Association of Arrival Hemoglobin With Overtransfusion at 24 Hours in a Trauma Population

BACKGROUND

Hemorrhage control and resuscitative concepts have evolved in recent years, leading to aggressive use of blood products in trauma patients. There is subsequently a potential risk for overtransfusion, adverse effects, and waste associated with unnecessary transfusion. Methods for conserving blood products are of particular importance in future large-scale combat operations where supply chains are likely to be strained. This study examined the association of emergency department (ED) arrival hemoglobin (HGB) with overtransfusion among survivors at 24 hours after major trauma at a military trauma center.

MATERIALS AND METHODS

We performed a retrospective cohort study of patients who had a "major trauma" activation and received any red blood cells. Overtransfusion was defined as a HGB level ≥11.0 g/dL at 24 hours (outcome variable). Multivariable logistic regression statistics were used to compare groups and adjust for confounders (injury severity score, arrival modified shock index, injury type, age, and gender). A receiver operating characteristic was constructed with overtransfusion at 24 hours as the outcome (binary) and arrival HGB (continuous) as the independent variable.

RESULTS

A total of 382 patients met inclusion criteria. Overtransfusion occurred in 30.4% (n = 116) of patients, with mean ED HGB levels of 13.2 g/dL (12.9 to 13.6) versus 11.6 g/dL (11.3 to 11.8, P < .001). Receiver operating characteristic analysis showed that ED HGB was highly sensitive (0.931) for predicting 24-hour overtransfusion. In our multivariable logistic regression analysis, when adjusting for injury severity score, arrival modified shock index, injury type, age, and gender, we found that the ED HGB value had a per-unit odds ratio of 1.60 (95% CI, 1.38 to 1.86) for 24-hour overtransfusion. Hospital and intensive care unit length of stay, mechanical ventilator days, and mortality did not increase.

CONCLUSION

We found that the arrival HGB value was associated with overtransfusion among 24-hour survivors in a civilian trauma setting. Our findings will inform future prospective studies that investigate blood sparing clinical practice guidelines.

Assessing the one-month mortality impact of civilian-setting prehospital transfusion: A systematic review and meta-analysis

BACKGROUND

Based on convincing evidence for outcomes improvement in the military setting, the past decade has seen evaluation of prehospital transfusion (PHT) in the civilian emergency medical services (EMS) setting. Evidence synthesis has been challenging, due to study design variation with respect to both exposure (type of blood product administered) and outcome (endpoint definitions and timing). The goal of the current meta-analysis was to execute an overarching assessment of all civilian-arena randomized controlled trial (RCT) evidence focusing on administration of blood products compared to control of no blood products.

METHOD

The review structure followed the Cochrane group's Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA). Using the Transfusion Evidence Library (transfusionevidencelibrary.com), the multidatabase (e.g. PubMed, EMBASE) Harvard On-Line Library Information System (HOLLIS), and GoogleScholar, we accessed many databases and gray literature sources. RCTs of PHT in the civilian setting with a comparison group receiving no blood products with 1-month mortality outcomes were identified.

RESULTS

In assessing a single patient-centered endpoint-1-month mortality-we calculated an overall risk ratio (RR) estimate. Analysis of three RCTs yielded a model with acceptable heterogeneity (I2 = 48%, Q-test p = 0.13). Pooled estimate revealed civilian PHT results in a statistically nonsignificant (p = 0.38) relative mortality reduction of 13% (RR 0.87, 95% CI 0.63-1.19).

CONCLUSIONS

Current evidence does not demonstrate 1-month mortality benefit of civilian-setting PHT. This should give pause to EMS systems considering adoption of civilian-setting PHT programs. Further studies should not only focus on which formulations of blood products might improve outcomes but also focus on which patients are most likely to benefit from any form of civilian-setting PHT.

Survival bias in pediatric hemorrhagic shock: Are we misrepresenting the data?

BACKGROUND

Studies of hemorrhage following pediatric injury often use the occurrence of transfusion as a surrogate definition for the clinical need for a transfusion. Using this approach, patients who are bleeding but die before receiving a transfusion are misclassified as not needing a transfusion. In this study, we aimed to evaluate the potential for this survival bias and to estimate its presence among a retrospective observational cohort of children and adolescents who died from injury.

METHODS

We obtained patient, injury, and resuscitation characteristics from the 2017 to 2020 Trauma Quality Improvement Program database of children and adolescents (younger than 18 years) who arrived with or without signs of life and died. We performed univariate analysis and a multivariable logistic regression to analyze the association between the time to death and the occurrence of transfusion within 4 hours after hospital arrival controlling for initial vital signs, injury type, body regions injured, and scene versus transfer status.

RESULTS

We included 6,063 children who died from either a blunt or penetrating injury. We observed that children who died within 15 minutes had lower odds of receiving a transfusion (odds ratio, 0.1; 95% confidence interval, 0.1-0.2) compared with those who survived longer. We estimated that survival bias that occurs when using transfusion administration alone to define hemorrhagic shock may occur in up to 11% of all children who died following a blunt or penetrating injury but less than 1% of all children managed as trauma activations.

CONCLUSION

Using the occurrence of transfusion alone may underestimate the number of children who die from uncontrolled hemorrhage early after injury. Additional variables than just transfusion administration are needed to more accurately identify the presence of hemorrhagic shock among injured children and adolescents.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.

Strategies to Obtain and Deliver Blood Products Into Critically Injured Children: A Survey of Pediatric Trauma Society Members

OBJECTIVES

Timely transfusion is associated with improved survival and a reduction in in-hospital morbidity. The benefits of early hemorrhagic shock recognition may be limited by barriers to accessing blood products and their timely administration. We examined how pediatric trauma programs obtain blood products, the types of rapid infusion models used, and the metrics tracked to improve transfusion process efficiency in their emergency department (ED).

METHODS

We developed and distributed a self-report survey to members of the Pediatric Trauma Society. The survey consisted of 6 initial questions, including the respondent's role and institution, whether a blood storage refrigerator was present in their ED, the rapid infuser model used to transfuse critically injured children in their ED, if their program tracked 4 transfusion process metrics, and if a video recording system was present in the trauma bay. Based on these responses, additional questions were prompted with an option for a free-text response.

RESULTS

We received 137 responses from 77 institutions. Most pediatric trauma programs have a blood storage refrigerator in the ED (n = 46, 59.7%) and use a Belmont rapid infuser to transfuse critically injured children (n = 45, 58.4%). The American College of Surgeons Level 1 designated trauma programs, or state-based equivalents, and "pediatric" trauma programs were more likely to have video recording systems for performance improvement review compared with lower designated trauma programs and "combined pediatric and adult" trauma programs, respectively.

CONCLUSIONS

Strategies to improve the timely acquisition and infusion of blood products to critically injured children are underreported. This study examined the current practices that pediatric trauma programs use to transfuse critically injured children and may provide a resource for trauma programs to cite for transfusion-related quality improvement.

Pre-Hospital Blood Products for the Care of Bleeding Trauma Patients

BACKGROUND

Controversy surrounds the administration of blood products to severely traumatized patients before they arrive in the hospital in order to compensate for early blood loss and/or to correct coagulation disturbances that arise shortly after the traumatic event. A number of terrestrial and air rescue services have begun to provide this kind of treatment.

METHODS

This review is based on articles using the PICO framework, published from January 2001 to January 2021, that were retrieved by a selective search, with structured searching strategies and searching bundles in Medline (OVIDSP), the Cochrane Central Register of Controlled Trials (CENTRAL), and Epistemonikos. A demand analysis was carried out on the basis of data from the trauma registry of the German Society of Trauma Surgery (TR-DGU) and practical experience from program development and implementation was provided by the Bundeswehr Hospital Ulm.

RESULTS

The currently available evidence on the pre-hospital administration of blood products in the early treatment of severely injured patients is based largely on retrospective, single-center case series. Two randomized controlled trials (RCTs) concerning the early use of fresh frozen plasma concentrates have yielded partly conflicting results. Three further RCTs on the use of lyophilized plasma (lyplas), lyplas plus erythrocyte concentrate, or whole blood likewise revealed non-uniform effects on short-term and intermediate-term mortality. Our demand analysis based on data from the TR-DGU showed that 300 to 1800 patients per year in Germany could benefit from the pre-hospital administration of blood products. This might be indicated in patients who have systolic hypotension (<100 mmHg) in combination with a suspected or confirmed hemorrhage, as well as pathological shock parameters in the point-of-care diagnostic testing performed on the scene (serum base excess ≤ -2.5 mmol/L and/or serum lactate concentration >4 mmol/L).

CONCLUSION

The studies that have been published to date yield no clear evidence either for or against the early pre-hospital administration of blood products. Any treatment of this kind should be accompanied by scientific evaluation.

Time is tissue: Barriers to timely transfusion after pediatric injury

ABSTRACT

Strategies to improve outcomes among children and adolescents in hemorrhagic shock have primarily focused on component resuscitation, pharmaceutical coagulation adjuncts, and hemorrhage control techniques. Many of these strategies have been associated with better outcomes in children, but the barriers to their use and the impact of timely use on morbidity and mortality have received little attention. Because transfusion is uncommon in injured children, few studies have identified and described barriers to the processes of using these interventions in bleeding patients, processes that move from the decision to transfuse, to obtaining the necessary blood products and adjuncts, and to delivering them to the patient. In this review, we identify and describe the steps needed to ensure timely blood transfusion and propose practices to minimize barriers in this process. Given the potential impact of time on hemorrhage associated outcomes, ensuring timely intervention may have a similar or greater impact than the interventions themselves.