Prehospital hemostatic resuscitation to achieve zero preventable deaths after traumatic injury:

Population pharmacokinetic modelling and simulation of tranexamic acid in adult trauma patients

AIMS

The aim of this study is to describe the disposition of tranexamic acid (TXA) in adult trauma patients and derive a dosing regimen that optimizes exposure based on a predefined exposure target.

METHODS

We performed a population pharmacokinetic (popPK) analysis of participants enrolled in the Tranexamic Acid Mechanisms and Pharmacokinetics in Traumatic Injury (TAMPITI) trial (≥18 years with traumatic injury, given ≥1 blood product and/or requiring immediate transfer to the operating room) who were randomized to a single dose of either 2 or 4 g of TXA ≤2 h from time of injury. PopPK analysis was conducted using nonlinear mixed-effects modelling (NONMEM). Simulations were then performed using the final model to generate estimated plasma TXA concentrations in 1000 simulated participants. Dosing schemes were evaluated to determine maintenance of TXA plasma concentrations >10 mg/L for ≥8 h after administration of the initial dose.

RESULTS

TXA PK was best described by a two-compartment model with proportional residual error and allometric scaling on all parameters. Platelet count, skeletal muscle oxygen saturation measured by near-infrared spectroscopy and interleukin-8 concentration were significant covariates on TXA clearance. Based on simulations, a 2 g IV bolus dose, repeated 3 h later, best achieved the target exposure.

CONCLUSIONS

According to simulations from a popPK model of TXA, a 2 g IV bolus with a repeated dose 3 h later would be most likely to maintain concentrations >10 mg/L for 8 h in >95% of adult trauma patients and should be considered for patients with ongoing haemorrhage.

Faster refill in an urban emergency medical services system saves lives: A prospective preliminary evaluation of a prehospital advanced resuscitative care bundle

INTRODUCTION

Military experience has demonstrated mortality improvement when advanced resuscitative care (ARC) is provided for trauma patients with severe hemorrhage. The benefits of ARC for trauma in civilian emergency medical services (EMS) systems with short transport intervals are still unknown. We hypothesized that ARC implementation in an urban EMS system would reduce in-hospital mortality.

METHODS

This was a prospective analysis of ARC bundle administration between 2021 and 2023 in an urban EMS system with 70,000 annual responses. The ARC bundle consisted of calcium, tranexamic acid, and packed red blood cells via a rapid infuser. Advanced resuscitative care patients were compared with trauma registry controls from 2016 to 2019. Included were patients with a penetrating injury and systolic blood pressure ≤90 mm Hg. Excluded were isolated head trauma or prehospital cardiac arrest. In-hospital mortality was the primary outcome of interest.

RESULTS

A total of 210 patients (ARC, 61; controls, 149) met the criteria. The median age was 32 years, with no difference in demographics, initial systolic blood pressure or heart rate recorded by EMS, or New Injury Severity Score between groups. At hospital arrival, ARC patients had lower median heart rate and shock index than controls ( p ≤ 0.03). Fewer patients in the ARC group required prehospital advanced airway placement ( p < 0.001). Twenty-four-hour and total in-hospital mortality were lower in the ARC group ( p ≤ 0.04). Multivariable regression revealed an independent reduction in in-hospital mortality with ARC (odds ratio, 0.19; 95% confidence interval, 0.05-0.68; p = 0.01).

CONCLUSION

Early ARC in a fast-paced urban EMS system is achievable and may improve physiologic derangements while decreasing patient mortality. Advanced resuscitative care closer to the point of injury warrants consideration.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

Chitosan nonwoven fabric composited calcium alginate and adenosine diphosphate as a hemostatic bandage for acute bleeding wounds

Acute bleeding following accidental injury is a leading cause of mortality. However, conventional hemostatic bandages impede wound healing by inducing excessive blood loss, dehydration, and adherence to granulation tissue. Strategies such as incorporating active hemostatic agents and implementing chemical modifications can augment the properties of these bandages. Nevertheless, the presence of remote thrombosis and initiators may pose risks to human health. Here, a hemostatic bandage was developed by physically combined chitosan nonwoven fabric, calcium alginate sponge, and adenosine diphosphate. The presented hemostatic bandage not only exhibits active and passive mechanisms for promoting clotting but also demonstrates excellent mechanical properties, breathability, ease of removal without causing damage to the wound bed or surrounding tissues, as well as maintaining an optimal moist environment conducive to wound healing. In vitro evaluation results indicated that the hemostatic bandage possesses favorable cytocompatibility with low levels of hemolysis. Furthermore, it effectively aggregates various blood cells while activating platelets synergistically to promote both extrinsic and intrinsic coagulation pathways. In an in vivo rat model study involving liver laceration and femoral artery injury scenarios, our developed hemostatic bandage demonstrated rapid clot formation capabilities along with reduced blood loss compared to commercially available fabrics.

Emergency preparedness for mass casualty events: South Texas commentary on the development of a statewide emergency response system

Mass casualty incidents (MCIs) are on the rise in the USA, and hemorrhage is the leading cause of preventable death in trauma. The need for rapid access to life-saving blood and blood products is essential for preventing death due to hemorrhage. It is well established that most major cities in the USA are underprepared to meet blood transfusion requirements in the event of an MCI. The South Texas Whole Blood Consortium sought to rectify this and vowed to be prepared to provide low-titer type O-positive whole blood (LTOWB) and blood components to the people who need it, where and when they need it. This system was able to transport 25 units of LTOWB and packed red blood cells almost 100 miles away to Uvalde Memorial Hospital within just 67 minutes after notification of an active shooter. The regional consortium has created a pool of dedicated LTOWB donors affectionately called Heroes in Arms who can be called on to instantly augment locoregional blood supply. Previously pregnant women have historically been excluded from donating plasma and LTOWB due to the increased rates of human leukocyte antigen (HLA) antibody (Ab) positivity, which is associated with transfusion-related acute lung injury. However, the South Texas Blood and Tissue Center in San Antonio had a large number of qualified, previously pregnant females desire to join the Heroes in Arms program prompting them to assess the feasibility of providing HLA Ab testing for this demographic and the results were promising. This is the first report of previously pregnant women being included in the pool for donation of LTOWB.

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.

Evaluation of the association of factor XIII at hospital arrival and outcomes in a cohort of severely injured patients

BACKGROUND

Severe traumatic bleeding depletes coagulation factor XIII (FXIII) and fibrinogen. However, the role of FXIII level in bleeding-related outcomes is unknown.

OBJECTIVES

To evaluate the association between FXIII levels at hospital arrival and critical administration threshold (≥3 red blood cell units in 1 hour within the first 24 hours), bleeding-related outcomes, death, and baseline characteristics.

METHODS

A retrospective cohort study was conducted in severely injured adult patients (Injury Severity Score of ≥22 or ≥2 red blood cell units transfused in 24 hours) admitted to a level 1 trauma center. Clinical and laboratory data were collected. Baseline FXIII antigen levels were measured in banked patient plasma. Multivariable logistic and linear regression models were used to estimate the association between FXIII levels, outcomes, and baseline characteristics.

RESULTS

Three hundred sixty-four of 1730 subjects admitted during a 2-year period were analyzed. Median age was 44 years (IQR, 27-62 years), and median Injury Severity Score was 29 (IQR, 22-34). FXIII levels were not associated with critical administration threshold (odds ratio [OR], 1.06; 95% CI, 0.97-1.17) or death (OR, 0.98; 95% CI, 0.90-1.07). FXIII was associated with major bleeding (OR, 1.10; 95% CI, 1.02-1.2) and massive transfusion (OR, 1.25; 95% CI, 1.08-1.44). Lower baseline FXIII levels were associated with arrival from a referring hospital (FXIII level, -0.07 U/mL; 95% CI, -0.11 to -0.03), hemoglobin (FXIII level, -0.05 U/mL; 95% CI, -0.07 to -0.03), fibrinogen level (FXIII level, -0.05 U/mL; 95% CI, -0.08 to -0.02), and platelet count (FXIII level, -0.02 U/mL; 95% CI, -0.04 to -0.008).

CONCLUSIONS

Baseline FXIII levels in severely injured patients were inconsistently associated with bleeding-related outcomes and mortality. However, their association with major bleeding warrants further investigation of the role of FXIII in massively transfused patients with trauma.

Time to Whole Blood Transfusion in Hemorrhaging Civilian Trauma Patients: There Is Always Room for Improvement

BACKGROUND

Whole blood (WB) is becoming the preferred product for the resuscitation of hemorrhaging trauma patients. However, there is a lack of data on the optimum timing of receiving WB. We aimed to assess the effect of time to WB transfusion on the outcomes of trauma patients.

STUDY DESIGN

The American College of Surgeons TQIP 2017 to 2019 database was analyzed. Adult trauma patients who received at least 1 unit of WB within the first 2 hours of admission were included. Patients were stratified by time to first unit of WB transfusion (first 30 minutes, second 30 minutes, and second hour). Primary outcomes were 24-hour and in-hospital mortality, adjusting for potential confounders.

RESULTS

A total of 1,952 patients were identified. Mean age and systolic blood pressure were 42 ± 18 years and 101 ± 35 mmHg, respectively. Median Injury Severity Score was 17 [10 to 26], and all groups had comparable injury severities (p = 0.27). Overall, 24-hour and in-hospital mortality rates were 14% and 19%, respectively. Transfusion of WB after 30 minutes was progressively associated with increased adjusted odds of 24-hour mortality (second 30 minutes: adjusted odds ratio [aOR] 2.07, p = 0.015; second hour: aOR 2.39, p = 0.010) and in-hospital mortality (second 30 minutes: aOR 1.79, p = 0.025; second hour: aOR 1.98, p = 0.018). On subanalysis of patients with an admission shock index >1, every 30-minute delay in WB transfusion was associated with higher odds of 24-hour (aOR 1.23, p = 0.019) and in-hospital (aOR 1.18, p = 0.033) mortality.

CONCLUSIONS

Every minute delay in WB transfusion is associated with a 2% increase in odds of 24-hour and in-hospital mortality among hemorrhaging trauma patients. WB should be readily available and easily accessible in the trauma bay for the early resuscitation of hemorrhaging patients.

An unmanned emergency blood dispatch system based on an early prediction and fast delivery strategy: Design and development study

BACKGROUND AND OBJECTIVE

For severe trauma patients, hemorrhage is the most common cause of medically preventable deaths. Early transfusion is beneficial to major hemorrhagic patients. However, the early supply of emergency blood products for major hemorrhagic patients is still a major problem in many areas. The aim of this study was to design and develop an unmanned emergency blood dispatch system for the fast delivery of blood resources and rapid emergency response to trauma events, especially those with mass hemorrhagic trauma patients and those occurred in remote areas.

METHODS

Based on the process of emergency medical services for trauma patients, we introduced unmanned aerial vehicle (UAV) and designed the main flowchart of the dispatch system, which combines an emergency transfusion prediction model and UAV-related dispatch algorithms to improve first aid efficiency and quality. The system identifies patients in need of emergency transfusion through a multidimensional prediction model. Then, by analyzing the blood center, hospitals and UAV stations nearby, the system recommends the patient's transfer destination for emergency transfusion and dispatch schemes of UAVs and trucks for a fast supply of blood products. Simulation experiments of urban and rural scenarios were conducted to evaluate the proposed system.

RESULTS

The developed emergency transfusion prediction model of the proposed system achieves a higher AUROC value of 0.8453 than a classical transfusion prediction score. In the urban experiment, by adopting the proposed system, the average wait time per patient decreased from 32 to 18 min, and the total time decreased from 42 to 29 min. Owing to the combination of the prediction and the fast delivery function, the proposed system took 4 and 11 min less wait time than the strategy with only the prediction function and the strategy with only the fast delivery function, respectively. In the rural experiment, for trauma patients requiring an emergency transfusion at 4 locations, the wait time for transfusion under the proposed system was 16.54, 17.08, 38.70 and 46.00 min less than that under the conventional strategy. The health status-related score increased by 6.9%, 0.9%, 19.1% and 36.7%, respectively.

CONCLUSIONS

Experimental results demonstrate that the proposed system works well with a faster blood supply speed for severe hemorrhagic patients and better health status. With the assistance of the system, emergency doctors at the scene of an injury are able to comprehensively analyze patients' status and the surrounding rescue conditions and then make decisions, especially when encountering mass casualties or casualties in remote areas.

Platelet-Inspired Intravenous Nanomedicine for Injury-Targeted Direct Delivery of Thrombin to Augment Hemostasis in Coagulopathies

Severe hemorrhage associated with trauma, surgery, and congenital or drug-induced coagulopathies can be life-threatening and requires rapid hemostatic management via topical, intracavitary, or intravenous routes. For injuries that are not easily accessible externally, intravenous hemostatic approaches are needed. The clinical gold standard for this is transfusion of blood products, but due to donor dependence, specialized storage requirements, high risk of contamination, and short shelf life, blood product use faces significant challenges. Consequently, recent research efforts are being focused on designing biosynthetic intravenous hemostats, using intravenous nanoparticles and polymer systems. Here we report on the design and evaluation of thrombin-loaded injury-site-targeted lipid nanoparticles (t-TLNPs) that can specifically localize at an injury site via platelet-mimetic anchorage to the von Willebrand factor (vWF) and collagen and directly release thrombin via diffusion and phospholipase-triggered particle destabilization, which can locally augment fibrin generation from fibrinogen for hemostatic action. We evaluated t-TLNPs in vitro in human blood and plasma, where hemostatic defects were created by platelet depletion and anticoagulation. Spectrophotometric studies of fibrin generation, rotational thromboelastometry (ROTEM)-based studies of clot viscoelasticity, and BioFlux-based real-time imaging of fibrin generation under simulated vascular flow conditions confirmed that t-TLNPs can restore fibrin in hemostatic dysfunction settings. Finally, the in vivo feasibility of t-TLNPs was tested by prophylactic administration in a tail-clip model and emergency administration in a liver-laceration model in mice with induced hemostatic defects. Treatment with t-TLNPs was able to significantly reduce bleeding in both models. Our studies demonstrate an intravenous nanomedicine approach for injury-site-targeted direct delivery of thrombin to augment hemostasis.

Why are bleeding trauma patients still dying? Towards a systems hypothesis of trauma

Over the years, many explanations have been put forward to explain early and late deaths following hemorrhagic trauma. Most include single-event, sequential contributions from sympathetic hyperactivity, endotheliopathy, trauma-induced coagulopathy (TIC), hyperinflammation, immune dysfunction, ATP deficit and multiple organ failure (MOF). We view early and late deaths as a systems failure, not as a series of manifestations that occur over time. The traditional approach appears to be a by-product of last century’s highly reductionist, single-nodal thinking, which also extends to patient management, drug treatment and drug design. Current practices appear to focus more on alleviating symptoms rather than addressing the underlying problem. In this review, we discuss the importance of the system, and focus on the brain’s “privilege” status to control secondary injury processes. Loss of status from blood brain barrier damage may be responsible for poor outcomes. We present a unified Systems Hypothesis Of Trauma (SHOT) which involves: 1) CNS-cardiovascular coupling, 2) Endothelial-glycocalyx health, and 3) Mitochondrial integrity. If central control of cardiovascular coupling is maintained, we hypothesize that the endothelium will be protected, mitochondrial energetics will be maintained, and immune dysregulation, inflammation, TIC and MOF will be minimized. Another overlooked contributor to early and late deaths following hemorrhagic trauma is from the trauma of emergent surgery itself. This adds further stress to central control of secondary injury processes. New point-of-care drug therapies are required to switch the body’s genomic and proteomic programs from an injury phenotype to a survival phenotype. Currently, no drug therapy exists that targets the whole system following major trauma.

The risk of thromboembolic events with early intravenous 2- and 4-g bolus dosing of tranexamic acid compared to placebo in patients with severe traumatic bleeding: A secondary analysis of a randomized, double-blind, placebo-controlled, single-center trial

BACKGROUND

Screening for the risk of thromboembolism (TE) due to tranexamic acid (TXA) in patients with severe traumatic injury has not been performed in randomized clinical trials. Our objective was to determine if TXA dose was independently-associated with thromboembolism.

STUDY DESIGN AND METHODS

This is a secondary analysis of a single-center, double-blinded, randomized controlled trial comparing placebo to a 2-g or 4-g intravenous TXA bolus dose in trauma patients with severe injury. We used multivariable discrete-time Cox regression models to identify associations with risk for thromboembolic events within 30 days post-enrollment. Event curves were created using discrete-time Cox regression.

RESULTS

There were 50 patients in the placebo group, 49 in the 2-g, and 50 in the 4-g TXA group. In adjusted analyses for thromboembolism, a 2-g dose of TXA had an hazard ratio (HR, 95% confidence interval [CI]) of 3.20 (1.12-9.11) (p = .029), and a 4-g dose of TXA had an HR (95% CI) of 5.33 (1.94-14.63) (p = .001). Event curves demonstrated a higher probability of thromboembolism for both doses of TXA compared to placebo. Other parameters independently associated with thromboembolism include time from injury to TXA administration, body mass index, and total blood products transfused.

DISCUSSION

In patients with severe traumatic injury, there was a dose-dependent increase in the risk of at least one thromboembolic event with TXA. TXA should not be withheld, but thromboembolism screening should be considered for patients receiving a dose of at least 2-g TXA intravenously for traumatic hemorrhage.

It is time to look in the mirror: Individual surgeon outcomes after emergent trauma laparotomy

BACKGROUND

Multiple quality indicators are used by trauma programs to decrease variation and improve outcomes. However, little if any provider level outcomes related to surgical procedures are reviewed. Emergent trauma laparotomy (ETL) is arguably the signature case that trauma surgeons perform on a regular basis, but few data exist to facilitate benchmarking of individual surgeon outcomes. As part of our comprehensive performance improvement program, we examined outcomes by surgeon for those who routinely perform ETL.

METHODS

A retrospective cohort study of patients undergoing ETL directly from the trauma bay by trauma faculty from December 2019 to February 2021 was conducted. Patients were excluded from mortality analysis if they required resuscitative thoracotomy for arrest before ETL. Surgeons were compared by rates of damage control and mortality at multiple time points.

RESULTS

There were 242 ETL (7-32 ETLs per surgeon) performed by 14 faculties. Resuscitative thoracotomy was performed in 7.0% (n = 17) before ETL. Six patients without resuscitative thoracotomy died intraoperatively and damage-control laparotomy was performed on 31.9% (n = 72 of 226 patients). Mortality was 4.0% (n = 9) at 24 hours and 7.1% (n = 16) overall. Median Injury Severity Score (p = 0.21), new injury severity score (p = 0.21), and time in emergency department were similar overall among surgeons (p = 0.15), while operative time varied significantly (40-469 minutes; p = 0.005). There were significant differences between rates of individual surgeon's mortality (range [hospital mortality], 0-25%) and damage-control laparotomy (range, 14-63%) in ETL.

CONCLUSION

Significant differences exist in outcomes by surgeon after ETL. Benchmarking surgeon level performance is a necessary natural progression of quality assurance programs for individual trauma centers. Additional data from multiple centers will be vital to allow for development of more granular quality metrics to foster introspective case review and quality improvement.

LEVEL OF EVIDENCE

Therapeutic/care management, level III.

The Role of Whole Blood Transfusions in Civilian Trauma: A Review of Literature in Military and Civilian Trauma

Resuscitation techniques for the management of adult trauma patients have evolved over the 20th century. Whole blood transfusions were previously used as the standard of care, whereas blood component therapy is the current method employed across most trauma centers across the United States. Prior to the transition, no studies were conducted to show improved efficacy of hemostatic potential in trauma patients. Recent conflicts in Iraq and Afghanistan have challenged the dogma that whole blood transfusions are not the standard of care and have shown potential as the superior transfusion product for adult trauma patients. The purpose of this review is to provide a comprehensive review and elucidate if whole blood transfusions have a role in civilian trauma patients based upon recent military medical literature and civilian pilot studies using whole blood transfusions.

Blood Group Testing

Red blood cell (RBC) transfusion is one of the most frequently performed clinical procedures and therapies to improve tissue oxygen delivery in hospitalized patients worldwide. Generally, the cross-match is the mandatory test in place to meet the clinical needs of RBC transfusion by examining donor-recipient compatibility with antigens and antibodies of blood groups. Blood groups are usually an individual's combination of antigens on the surface of RBCs, typically of the ABO blood group system and the RH blood group system. Accurate and reliable blood group typing is critical before blood transfusion. Serological testing is the routine method for blood group typing based on hemagglutination reactions with RBC antigens against specific antibodies. Nevertheless, emerging technologies for blood group testing may be alternative and supplemental approaches when serological methods cannot determine blood groups. Moreover, some new technologies, such as the evolving applications of blood group genotyping, can precisely identify variant antigens for clinical significance. Therefore, this review mainly presents a clinical overview and perspective of emerging technologies in blood group testing based on the literature. Collectively, this may highlight the most promising strategies and promote blood group typing development to ensure blood transfusion safety.

Digital Microfluidic Hemagglutination Assays for Blood Typing, Donor Compatibility Testing, and Hematocrit Analysis

BACKGROUND

Blood typing, donor compatibility testing, and hematocrit analysis are common tests that are important in many clinical applications, including those found in high-stakes settings such as the trauma center. These tests are typically performed in centralized laboratories with sample batching; the minutes that are lost in this mode can lead to adverse outcomes, especially for critical-care patients. As a step toward providing rapid results at the bedside, we developed a point-of-care hemagglutination system relying on digital microfluidics (DMF) and a unique, automated readout tool, droplet agglutination assessment using digital microfluidics (DAAD).

METHODS

ABO and Rhesus blood grouping, donor crossmatching, and hematocrit assays were developed on a portable DMF platform that allowed for automated sample processing. The result of each assay could be determined by eye or automatically with the DAAD imaging tool.

RESULTS

DMF-DAAD was applied to 109 samples collected from different sources (including commercial samples, pinpricks from volunteers, and a hospital blood bank), with perfect fidelity to gold-standard results. Some of these tests were carried out by a nonexpert in a hospital trauma center. Proof-of-concept results were also collected from smaller sample sets for donor compatibility testing and hematocrit analysis.

CONCLUSION

DMF-DAAD shows promise for delivering rapid, reliable results in a format well suited for a trauma center and other settings where every minute counts.

Stewardship of Prehospital Low Titer O-Positive Whole Blood in a Large Urban Fire-Based EMS System

Introduction: Trauma is the leading cause of death for those aged 1 to 46 years with most fatalities resulting from hemorrhage prior to arrival to hospital. Hemorrhagic shock patients receiving transfusion with 15 minutes experience lower mortality. Prehospital blood transfusion has many legal, fiduciary, and logistical issues. The San Antonio Fire Department participates in a consortium designed to enhance the stewardship of prehospital whole blood. This study aimed to stratify blood usage amongst the field supervisors and special operations units that carry whole blood. Methods: This was a 12-month retrospective analysis of blood usage. Blood tracking forms (used for either blood exchange of transfusion) were cross referenced with city financial records to determine blood usage patterns in the 7th Largest City in the US. We used descriptive statistics, compared usage ratios, and chi-square to compare dichotomized data. Results: A total of 363 whole blood units were obtained and 248 (68.3%) units of whole blood were transfused. EMS field supervisors transfused 74% of whole blood vs. 44% for special operations ambulances (p= <0.001). Response vehicles located in densely populated areas had the highest usage rates. All blood units were either transfused or returned for a zero blood unit wastage for expiration. Conclusion: The information contained within this work can provide other EMS agencies with a basic framework for comparison. The data from the SAFD's whole blood transfusion rate coupled with the clinical transfusion guideline has provided some insight for prospective agencies considering adopting a whole blood program. EMS systems and municipalities with similar characteristics can project their own whole blood needs and make informed decisions regarding program feasibility and design.

The Role of Plasma Transfusion in Pre-Hospital Haemostatic Resuscitation

Traumatic haemorrhage remains a major cause of preventable death and early haemostatic resuscitation is now a mainstay of treatment internationally. Recently, 2 randomized control trials (RCTs) - PAMPer (Prehospital Air Medical Plasma) and COMBAT (Control of Major Bleeding After Trauma), evaluating the effect of pre-hospital use of plasma on mortality provided conflicting results, raising important questions on the role of plasma resuscitation in pre-hospital environment. Both PAMPer (n = 501 patients) and COMBAT (n = 144 patients) trials were pragmatic RCTs that evaluated the effect of pre-hospital plasma transfusion (two units) versus standard of care on 28/30 days mortality in trauma patients who presented with clinical signs of haemorrhagic shock (defined as hypotension or tachycardia). The PAMPer trial showed that plasma transfusion reduced 30-day mortality compared with standard of care (23% vs 33%, 95% confidence interval -18.6; -1.0%; P = 0.03), while COMBAT trial showed no difference in 28-day survival. The post-hoc analyses of the 2 trials have suggested that the benefit of pre-hospital plasma transfusion may be greater for patients who are coagulopathic, have blunt injury and have a transport time from the scene of injury to the hospital of >20 minutes. In this review we evaluate strengths and limitations of the two trials and their differences and similarities, which may explain the conflicting results, as well as provide directions for future trials to better define the target population that would most benefit from pre-hospital plasma resuscitation. Further, considering the logistical challenges of carrying any blood components on an aircraft, cost/safety of plasma, and the scarcity of universal blood group donors, there is a need for a health economic evaluation of pre-hospital plasma transfusion in trauma patients, prior to this intervention becoming universal.

Advanced prehospital resuscitative care: Can we identify trauma patients who might benefit?

BACKGROUND

Uncontrolled truncal hemorrhage remains the most common cause of potentially preventable death after injury. The notion of earlier hemorrhage control and blood product resuscitation is therefore attractive. Some systems have successfully implemented prehospital advanced resuscitative care (ARC) teams. Early identification of patients is key and is reliant on rapid decision making and communication. The purpose of this simulation study was to explore the feasibility of early identification of patients who might benefit from ARC in a typical US setting.

METHODS

We conducted a prospective observational/simulation study at a level I trauma center and two associated emergency medical service (EMS) agencies over a 9-month period. The participating EMS agencies were asked to identify actual patients who might benefit from the activation of a hypothetical trauma center-based ARC team. This decision was then communicated in real time to the study team.

RESULTS

Sixty-three patients were determined to require activation. The number of activations per month ranged from 2 to 15. The highest incidence of calls occurred between 4 pm to midnight. Of the 63 patients, 33 were transported to the trauma center. The most common presentation was with penetrating trauma. The median age was 27 years (interquartile range, 24-45 years), 75% were male, and the median Injury Severity Score was 11 (interquartile range, 7-20). Based on injury patterns, treatment received, and outcomes, it was determined that 6 (18%) of 33 patients might have benefited from ARC. Three of the patients died en-route to or soon after arrival at the trauma center.

CONCLUSION

The prehospital identification of patients who might benefit from ARC is possible but faces challenges. Identifying strategies to adapt existing processes may allow better utilization of the existing infrastructure and should be a focus of future efforts.

LEVEL OF EVIDENCE

Prognostic/Epidemiologic, level III.

Prehospital whole blood reduces early mortality in patients with hemorrhagic shock

BACKGROUND

Low titer O+ whole blood (LTOWB) is being increasingly used for resuscitation of hemorrhagic shock in military and civilian settings. The objective of this study was to identify the impact of prehospital LTOWB on survival for patients in shock receiving prehospital LTOWB transfusion.

STUDY DESIGN AND METHODS

A single institutional trauma registry was queried for patients undergoing prehospital transfusion between 2015 and 2019. Patients were stratified based on prehospital LTOWB transfusion (PHT) or no prehospital transfusion (NT). Outcomes measured included emergency department (ED), 6-h and hospital mortality, change in shock index (SI), and incidence of massive transfusion. Statistical analyses were performed.

RESULTS

A total of 538 patients met inclusion criteria. Patients undergoing PHT had worse shock physiology (median SI 1.25 vs. 0.95, p < .001) with greater reversal of shock upon arrival (-0.28 vs. -0.002, p < .001). In a propensity-matched group of 214 patients with prehospital shock, 58 patients underwent PHT and 156 did not. Demographics were similar between the groups. Mean improvement in SI between scene and ED was greatest for patients in the PHT group with a lower trauma bay mortality (0% vs. 7%, p = .04). No survival benefit for patients in prehospital cardiac arrest receiving LTOWB was found (p > .05).

DISCUSSION

This study demonstrated that trauma patients who received prehospital LTOWB transfusion had a greater improvement in SI and a reduction in early mortality. Patient with prehospital cardiac arrest did not have an improvement in survival. These findings support LTOWB use in the prehospital setting. Further multi-institutional prospective studies are needed.

A new definition for massive transfusion in the modern era of whole blood resuscitation

BACKGROUND

Multiple thresholds are defined to identify patients at risk of death from hemorrhage, including massive transfusion (MT), critical administration threshold (CAT), and resuscitation intensity (RI). All fail to account for the use of whole blood (WB). We hypothesized that a definition including WB transfusion would better predict early mortality following trauma.

METHODS

This is a retrospective review of all trauma patients with activation of the MT protocol from December 2018 to February 2020. Combinations of WB, RBCs, and fresh frozen plasma (FFP) units transfused during the initial hour of resuscitation were compared using receiver operating characteristic and area under the receiver curve (AUC) for 3- and 6-h mortality. WB massive transfusion (WB MT) score was defined as the sum of each unit RBC plus three times each unit of WB transfused within the first hour of resuscitation.

RESULTS

There were 235 patients eligible for analysis with 60 resuscitated using ≥1 unit of WB. Overall, 27 and 29 patients died in the first 3 and 6 h, respectively. WB MT ≥7 had the greatest 3-h and 6-h mortality AUC values (0.78 and 0.79, respectively) when compared to MT, CAT, RI4+, and other attempted definitions using units of WB, RBC, and FFP. Compared to WB MT-, WB MT+ patients died at significantly higher rates at 3 h (28.9% vs. 3.1%, p < .001), 24 h (35.5% vs. 5.7%, p < .001), and 28 days (42.1% vs. 11.9%, p < .001).

CONCLUSION

WB MT is the first measure of massive resuscitation to incorporate WB and better identifies early mortality than other definitions.

Never-frozen liquid plasma transfusion in civilian trauma: a nationwide propensity-matched analysis

BACKGROUND

Never-frozen liquid plasma (LQP) was found to reduce component waste, decrease health care expenses, and have a superior hemostatic profile compared with fresh frozen plasma (FFP). Although transfusing LQP in hemorrhaging patients has become more common, its clinical effectiveness remains to be explored. This study aims to examine outcomes of trauma patients transfused with LQP compared with thawed FFP.

METHODS

Adult (≥18 years) trauma patients receiving early (≤4 hours) plasma transfusions were identified in the Trauma Quality Improvement Program 2017. Patients were stratified into those receiving LQP versus FFP. Propensity-score matching in a 1:2 ratio was performed. Primary outcome measures were mortality and time to first plasma unit transfusion. Secondary outcome measures were major complications and hospital length of stay.

RESULTS

A total of 107 adult trauma patients receiving LQP were matched to 214 patients receiving FFP. Mean age was 48 ± 19 years, 73% were male, and median Injury Severity Score was 27 [23-41]. A total of 42% of patients were in shock, 22% had penetrating injuries, and 31% required surgical intervention for hemorrhage control. Patients received a median of 4 [2-6] units of PRBC, 2 [1,3] units of LQP or FFP, and 1 [0-1] unit of platelets. The median time to the first LQP unit transfused was significantly shorter compared with the first FFP unit transfused (54 [28-79] minutes vs. 98 [59-133] minutes; p < 0.001). Rates of 24-hour mortality (2.8% vs. 3.7%; p = 0.664) and in-hospital mortality (16.8% vs. 20.1%; p = 0.481) were not different between the LQP and FFP groups. Similarly, there was no difference in major complications (15.9% vs. 21.5%; p = 0.233) and hospital length of stay (12 [6-21] vs. 12 [6-23] days; p = 0.826).

CONCLUSION

Never-frozen liquid plasma is safe and effective in resuscitating trauma patients. Never-frozen liquid plasma has the potential to expand our transfusion armamentarium given its longer storage time and immediate availability.

LEVEL OF EVIDENCE

Therapeutic, Level IV.

Angioembolization in intra-abdominal solid organ injury: Does delay in angioembolization affect outcomes?

INTRODUCTION

Angioembolization (AE) is an integral component in multidisciplinary algorithms for achieving hemostasis in patients with trauma. The American College of Surgeons Committee on Trauma recommends that interventional radiologists be available within 30 minutes to perform emergent AE. However, the impact of the timing of AE on patient outcomes is still not well known. We hypothesized that a delay in AE would be associated with increased mortality and higher blood transfusion requirements in patients with blunt intra-abdominal solid organ injury.

METHODS

A 4-year (2013-2016) retrospective review of the ACS Trauma Quality Improvement Program database was performed. We included adult patients (age, ≥18 years) with blunt intra-abdominal solid organ injury who underwent AE within 4 hours of hospital admission. Patients who underwent operative intervention before AE were excluded. The primary outcome was 24-hour mortality. The secondary outcome was blood product transfusions. Patients were grouped into four 1-hour intervals according to their time from admission to AE. Multivariate regression analysis was performed to accommodate patient differences.

RESULTS

We analyzed 1,009,922 trauma patients, of which 924 (1 hour, 76; 1-2 hours, 224; 2-3 hours, 350; 3-4 hours, 274) were deemed eligible. The mean ± SD age was 44 ± 19 years, and 66% were male. The mean ± SD time to AE was 144 ± 54 minutes, and 92% of patients underwent AE more than 1 hour after admission. Overall 24-hour mortality was 5.2%. On univariate analysis, patients receiving earlier AE had decreased 24-hour mortality (p = 0.016), but no decrease in blood products transfused. On regression analysis, every hour delay in AE was significantly associated with increased 24-hour mortality (p < 0.05).

CONCLUSION

Delayed AE for hemorrhagic control in blunt trauma patients with an intra-abdominal solid organ injury is associated with increased 24-hour mortality. Trauma centers should ensure timeliness of interventional radiologist availability to prevent a delay in vital AE, and it should be a focus of quality improvement projects.

LEVEL OF EVIDENCE

Prognostic, level III.

Nationwide analysis of whole blood hemostatic resuscitation in civilian trauma

INTRODUCTION

Renewed interest in whole blood (WB) resuscitation in civilians has emerged following its military use. There is a paucity of data on its role in civilians where balanced component therapy (CT) resuscitation is the standard of care. The aim of this study was to assess nationwide outcomes of using WB as an adjunct to CT versus CT alone in resuscitating civilian trauma patients.

METHODS

We analyzed the (2015-2016) Trauma Quality Improvement Program. We included adult (age, ≥18 years) trauma patients presenting with hemorrhagic shock and requiring at least 1 U of packed red blood cells (pRBCs) within 4 hours. Patients were stratified into WB-CT versus CT only. Primary outcomes were 24-hour and in-hospital mortality. Secondary outcomes were hospital length of stay and major complications. Hierarchical logistic regression was performed to account for clustering effect within hospitals and adjusting for patient- and hospital-level potential confounding factors.

RESULTS

A total of 8,494 patients were identified, of which 280 received WB-CT (WB, 1 [1-1]; pRBC, 16 [10-23]; FFP, 9 [6-16]; platelets, 3 [2-5]) and 8,214 received CT only (pRBC, 15 [10-24]; FFP, 10 [6-16]; platelets, 2 [1-4]). Mean ± SD age was 34 ± 16 years, 79% were male, Injury Severity Score was 33 (24-43), and 63% had penetrating injuries. Patients who received WB-CT had a lower 24-hour mortality (17% vs. 25%; p = 0.002), in-hospital mortality (29% vs. 40%; p < 0.001), major complications (29% vs. 41%; p < 0.001), and a shorter length of stay (9 [7-12] vs. 15 [10-21]; p = 0.011). On regression analysis, WB was independently associated with reduced 24-hour mortality (odds ratio [OR], 0.78 [0.59-0.89]; p = 0.006), in-hospital mortality (OR, 0.88 [0.81-0.90]; p = 0.011), and major complications (OR, 0.92 [0.87-0.96]; p = 0.013).

CONCLUSION

The use of WB as an adjunct to CT is associated with improved outcomes in resuscitation of severely injured civilian trauma patients. Further studies are required to evaluate the role of adding WB to massive transfusion protocols.

LEVEL OF EVIDENCE

Therapeutic, level IV.

The Immunologic Effect of Early Intravenous Two and Four Gram Bolus Dosing of Tranexamic Acid Compared to Placebo in Patients With Severe Traumatic Bleeding (TAMPITI): A Randomized, Double-Blind, Placebo-Controlled, Single-Center Trial

Background

The hemostatic properties of tranexamic acid (TXA) are well described, but the immunological effects of TXA administration after traumatic injury have not been thoroughly examined. We hypothesized TXA would reduce monocyte activation in bleeding trauma patients with severe injury.

Methods

This was a single center, double-blinded, randomized controlled trial (RCT) comparing placebo to a 2 g or 4 g intravenous TXA bolus dose in trauma patients with severe injury. Fifty patients were randomized into each study group. The primary outcome was a reduction in monocyte activation as measured by human leukocyte antigen-DR isotype (HLA-DR) expression on monocytes 72 h after TXA administration. Secondary outcomes included kinetic assessment of immune and hemostatic phenotypes within the 72 h window post-TXA administration.

Results

The trial occurred between March 2016 and September 2017, when data collection ended. 149 patients were analyzed (placebo, n = 50; 2 g TXA, n = 49; 4 g TXA, n = 50). The fold change in HLA-DR expression on monocytes [reported as median (Q1–Q3)] from pre-TXA to 72 h post-TXA was similar between placebo [0.61 (0.51–0.82)], 2 g TXA [0.57 (0.47–0.75)], and 4 g TXA [0.57 (0.44–0.89)] study groups (p = 0.82). Neutrophil CD62L expression was reduced in the 4 g TXA group [fold change: 0.73 (0.63–0.97)] compared to the placebo group [0.97 (0.78–1.10)] at 24 h post-TXA (p = 0.034). The fold decrease in plasma IL-6 was significantly less in the 4 g TXA group [1.36 (0.87–2.42)] compared to the placebo group [0.46 (0.19–1.69)] at 72 h post-TXA (p = 0.028). There were no differences in frequencies of myeloid or lymphoid populations or in classical complement activation at any of the study time points.

Conclusion

In trauma patients with severe injury, 4 g intravenous bolus dosing of TXA has minimal immunomodulatory effects with respect to leukocyte phenotypes and circulating cytokine levels.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier NCT02535949.

Civilian prehospital transfusion - experiences from a French region

BACKGROUND AND OBJECTIVES

Haemorrhagic shock is a leading cause of avoidable mortality in prehospital care. For several years, our centre has followed a procedure of transfusing two units of packed red blood cells outside the hospital. Our study's aim was twofold: describe the patient characteristics of those receiving prehospital blood transfusions and analyse risk factors for the 7-day mortality rate.

MATERIALS AND METHODS

We performed a monocentric retrospective observational study. Demographic and physiological data were recovered from medical records. The primary outcome was mortality at seven days for all causes. All patients receiving prehospital blood transfusions between 2013 and 2018 were included.

RESULTS

Out of 116 eligible patients, 56 patients received transfusions. Trauma patients (n = 18) were younger than medical patients (n = 38) (P = 0·012), had lower systolic blood pressure (P = 0·001) and had higher haemoglobin levels (P = 0·016). Mortality was higher in the trauma group than the medical group (P = 0·015). In-hospital trauma patients received more fresh-frozen plasma and platelet concentrate than medical patients (P < 0·05). Predictive factors of 7-day mortality included transfusion for trauma-related reasons, low Glasgow Coma Scale, low peripheral oxygen saturation, prehospital intensive resuscitation, existing coagulation disorders, acidosis and hyperlactataemia (P < 0·05).

CONCLUSION

Current guidelines recommend early transfusion in patients with haemorrhagic shock. Prehospital blood transfusions are safe. Coagulation disorders and acidosis remain a cause of premature death in patients with prehospital transfusions.

Temporal Dysregulation of the Angiopoietin-2/-1 Ratio After Trauma and Associations With Injury Characteristics and Outcomes

Traumatic injury and hemorrhagic shock result in endothelial cell activation and vascular dysfunction that, if not corrected, can propagate multiorgan failure. Angiopoietin-1 and angiopoietin-2 are important regulators of endothelial cell function, and the ratio of plasma angiopoietin-2-to-1 is a useful indicator of overall vascular health. We therefore characterized plasma angiopoietin-2/-1 ratios over time after trauma in adults in an effort to gain insight into the pathophysiology that may drive post-traumatic vasculopathy and organ injury. We performed a single-center prospective observational study to measure plasma angiopoietin-1 and -2 levels and determine angiopoietin-2/-1 ratios in adult trauma patients upon hospital arrival and after 12, 24, and 48 h. Compared with levels in healthy adults, angiopoietin-1 levels were significantly elevated at hospital arrival, and angiopoietin-2 levels were significantly elevated at 12, 24, and 48 h. These kinetics translated in angiopoietin-2/-1 ratios that were significantly greater than controls at 24 and 48 h. After regression analysis, elevated angiopoietin-2 levels were independently associated with blunt injuries at admission, with coagulopathy at admission and 12 h, and with hemorrhagic shock at 24 and 48 h. Significant correlations were observed between both angiopoietins and 24-h transfusion requirements. Angiopoietin-2/-1 ratios correlated with mechanical ventilation duration and intensive care unit and hospital lengths of stay. In this study, we demonstrate novel temporal associations between angiopoietin dysregulation and blunt injuries, acute coagulopathy, and hemorrhagic shock. Moreover, our findings highlight the presence of endothelial activation following traumatic insults in adults that may contribute to worse clinical outcomes.

From battlefront to homefront: creation of a civilian walking blood bank

Hemorrhagic shock remains the leading cause of preventable death on the battlefield, despite major advances in trauma care. Early initiation of balanced resuscitation has been shown to decrease mortality in the hemorrhaging patient. To address transfusion limitations in austere environments or in the event of multiple casualties, walking blood banks have been used in the combat setting with great success. Leveraging the success of the region-wide whole blood program in San Antonio, Texas, we report a novel plan that represents a model response to mass casualty incidents.

Metabolic phenotypes of standard and cold-stored platelets

BACKGROUND

Conventional platelet (PLT) storage at room temperature under continuous agitation results in a limited shelf life (5 days) and an increased risk of bacterial contamination. However, both of these aspects can be ameliorated by cold storage. Preliminary work has suggested that PLTs can be cold stored for up to 3 weeks, while preserving their metabolic activity longer than in PLTs stored at room temperature. As such, in the present study, we hypothesized that the metabolic phenotypes of PLTs stored at 4°C for 3 weeks could be comparable to that of room temperature-stored PLTs at 22°C for 5 days.

STUDY DESIGN AND METHODS

Metabolomics analyses were performed on nine apheresis PLT concentrates stored either at room temperature (22°C) for 5 days or refrigerated conditions (4°C) for up to 3 weeks.

RESULTS

Refrigeration did not impact the rate of decline in glutamine or the intracellular levels of Krebs cycle metabolites upstream to fumarate and malate. It did, however, decrease oxidant stress (to glutathione and purines) and slowed down the activation of the pentose phosphate pathway, glycolysis, and fatty acid metabolism (acyl-carnitines).

CONCLUSION

The overall metabolic phenotypes of 4°C PLTs at Storage Day 10 are comparable to PLTs stored at 22°C at the end of their 5-day shelf life, while additional changes in glycolysis, purine, and fatty acid metabolism are noted by Day 21.

Adenosine, Lidocaine, and Magnesium Support a High Flow, Hypotensive, Vasodilatory State With Improved Oxygen Delivery and Cerebral Protection in a Pig Model of Noncompressible Hemorrhage

BACKGROUND

Noncompressible hemorrhage is the leading cause of preventable death in military and civilian trauma. Our aim was to examine the effect of adenosine, lidocaine, and magnesium (Mg²⁺; ALM) on cardiovascular and cerebral function in a porcine hepatic hemorrhage model.

MATERIALS AND METHODS

Pigs (59.1 ± 0.34 kg) were anesthetized, instrumented, and randomly assigned into sham (n = 6), saline controls (n = 10) or ALM (n = 10) groups before laparoscopic liver resection. After 30 min, groups received 4 mL/kg 3% NaCl ± ALM bolus (Phase 1) followed 60 min later with 3 mL/kg/h 0.9% NaCl ± ALM drip (4 h; Phase 2), then transfusion. Hemodynamics, carotid artery flow, and intracranial pressure were measured continuously. Microdialysis samples were analyzed for metabolites.

RESULTS

Saline controls had 20% mortality (mean survival time: 307 ± 38 min) with no ALM deaths over 6 h. Bolus administration increased mean arterial pressure (MAP) in both groups, and drip led to further increases to 62 ± 10 mmHg in controls compared with a steady fall to 47 ± 8 mmHg in ALM group at 240 min. The lower MAP was associated with a dramatic fall in systemic vascular resistance and improved oxygen delivery. ALM drip significantly increased cardiac output and stroke volume with lower dP/dt_Min, indicating a less stiff heart. ALM drip also significantly decreased cerebral perfusion pressure, reduced cerebral oxygen consumption (28%), and reduced brain glycerol (60%), lactate (47%), and relative expression of hypoxia-inducible factor (38%) compared with saline controls.

CONCLUSIONS

ALM therapy improved cardiac function and oxygen delivery by lowering systemic vascular resistance after noncompressible hemorrhage. ALM also appeared to protect the brain at hypotensive MAPs with significantly lower cerebral perfusion pressure, lower O₂ consumption, and significantly lower cortical lactate and glycerol levels compared to saline controls.

Cold-stored whole blood in a Norwegian emergency helicopter service: an observational study on storage conditions and product quality

BACKGROUND

Increasing numbers of emergency medical service agencies and hospitals are developing the capability to administer blood products to patients with hemorrhagic shock. Cold-stored whole blood (WB) is the only single product available to prehospital providers who aim to deliver a balanced resuscitation strategy. However, there are no data on the safety and in vitro characteristics of prehospital stored WB. This study aimed to describe the effects on in vitro quality of storing WB at remote helicopter bases in thermal insulating containers.

STUDY DESIGN AND METHODS

We conducted a two-armed single-center study. Twenty units (test) were stored in airtight thermal insulating containers, and 20 units (controls) were stored according to routine procedures in the Haukeland University Hospital Blood Bank. Storage conditions were continuously monitored during emergency medical services missions and throughout remote and blood bank storage. Hematologic and metabolic variables, viscoelastic properties, and platelet (PLT) aggregation were measured on Days 1, 8, 14, and 21.

RESULTS

Storage conditions complied with the EU guidelines throughout remote and in-hospital storage for 21 days. There were no significant differences in PLT aggregation, viscoelastic properties, and hematology variables between the two groups. Minor significantly lower pH, glucose, and base excess and higher lactate were observed after storage in airtight containers.

CONCLUSION

Forward cold storage of WB is safe and complies with EU standards. No difference is observed in hemostatic properties. Minor differences in metabolic variables may be related to the anaerobic conditions within the thermal box.

Cold-stored leukoreduced CPDA-1 whole blood: in vitro quality and hemostatic properties

BACKGROUND

Some jurisdictions require leukoreduction of cellular blood components. The only whole blood collection set with a platelet-saving filter uses citrate-phosphate-dextrose (CPD) as storage solution. Substituting CPD with citrate-phosphate-dextrose-adenine (CPDA-1) increases shelf life from 21 to 35 days. This would simplify prehospital and rural resupply and reduce wastage. We investigated in vitro quality and hemostatic properties of CPDA-1 whole blood leukoreduced with a platelet-saving filter.

STUDY DESIGN AND METHODS

CPDA-1 whole blood was leukoreduced using a platelet-saving filter and stored 35 days. EDQM requirements, hematology, metabolic parameters, thromboelastography, light transmission aggregometry, fibrinogen, factor VIII, and interleukin-6 were measured on Days 0, 1, 14, 21, and 35 and compared to non-leukoreduced blood.

RESULTS

All units met EDQM requirements. Leukoreduction yielded residual white blood cell count <1 × 10⁶ and 87% platelet recovery on Day 1. It caused reduction in thromboelastography parameters, but not aggregometry response. No hemolysis >0.8% was observed. Factor VIII was higher on Day 35 in the leukoreduced group, 37.9 (95% CI: 26.0, 49.8) versus 13.8 (9.4, 18.2) IU/dL. In both groups, aggregation was significantly reduced by Day 14. Thromboelastography showed remaining platelet activity on Day 35, MA 46.9 (42.1, 51.7) in the leukoreduced and 44.3 (39.6, 49.0) mm in the non-leukoreduced group. Fibrinogen was within reference ranges at Day 35 (>2 g/dL). Interleukin-6 was not detectable.

CONCLUSION

Leukoreducing CPDA-1 whole blood with a platelet-saving filter did not compromise hemostatic properties. We encourage development of a single bag CPDA-1 whole blood collection set with in-line platelet-saving filter.

Prehospital blunt traumatic arrest resuscitation augmented by whole blood: a case report

BACKGROUND

Prehospital hemorrhagic shock accounts for approximately 25,000 civilian deaths annually in the United States. A balanced, blood-based resuscitation strategy is hypothesized to be the optimal treatment for these patients. Due to logistical constraints, delivering a balanced, blood-based resuscitation is difficult in the prehospital setting. A low titer O⁺ whole blood (LTO⁺ WB) ground ambulance initiative, may help alleviate this capability gap.

CASE REPORT

A 37-year-old female was involved in a motor vehicle collision at approximately 16:30. While she was trapped inside the vehicle, her mental status deteriorated. The patient was successfully extricated at 17:04 and found to be in cardiac arrest. The paramedics and firefighters quickly secured her airway and applied a mechanical CPR device. The first responder team obtained return of spontaneous circulation, but the patient's blood pressure was 43/27 mmHg. The paramedics transfused one unit of LTO⁺ WB. Twenty-one minutes after the initial LTO⁺ WB transfusion, the air ambulance team transfused a second unit of LTO⁺ WB. Upon hospital arrival, the transfusion was completed, and the patient's shock index improved to 1.0. The trauma team identified a grade 5 splenic injury with active extravasation. Interventional radiology performed an angiogram and successfully embolized the tertiary branches of the inferior splenic pole. She was extubated on postinjury Day one and discharged to her home neurologically intact on postinjury Day 12.

CONCLUSION

The prehospital availability of LTO⁺ WB may enhance the resuscitation of critically ill trauma patients.

The effect of platelet storage temperature on haemostatic, immune, and endothelial function: potential for personalised medicine

Reports from both adult and paediatric populations indicate that approximately two-thirds of platelet transfusions are used prophylactically to prevent bleeding, while the remaining one-third are used therapeutically to manage active bleeding. These two indications, prophylactic and therapeutic, serve two very distinct purposes and therefore will have two different functional requirements. In addition, disease aetiology in a given patient may require platelets with different functional characteristics. These characteristics can be derived from the various manufacturing methods used in platelet product production, including collection methods, processing methods, and storage options. The iterative combinations of manufacturing methods can result in a number of unique platelet products with different efficacy and safety profiles, which could potentially be used to benefit patient populations by meeting diverse clinical needs. In particular, cold storage of platelet products causes many biochemical and functional changes, of which the most notable characterised to date include increased haemostatic activity and altered expression of molecules inherent to platelet:leucocyte interactions. The in vivo consequences, both short- and long-term, of these molecular and cellular cold-storage-induced changes have yet to be clearly defined. Elucidation of these mechanisms would potentially reveal unique biologies that could be harnessed to provide more targeted therapies. To this end, in this new era of personalised medicine, perhaps there is an opportunity to provide individual patients with platelet products that are tailored to their clinical condition and the specific indication for transfusion.

Establishing a regional pediatric trauma preventable/potentially preventable death rate

PURPOSE

Although trauma is the leading cause of death for the pediatric population, few studies have addressed the preventable/potentially preventable death rate (PPPDR) attributable to trauma.

METHODS

This is a retrospective study of trauma-related death records occurring in Harris County, Texas in 2014. Descriptive and Chi-squared tests were conducted for two groups, pediatric and adult trauma deaths in relation to demographic characteristics, mechanism of injury, death location and survival time.

RESULTS

There were 105 pediatric (age < 18 years) and 1738 adult patients. The PPPDR for the pediatric group was 21.0%, whereas the PPPDR for the adult group was 37.2% (p = 0.001). Analysis showed fewer preventable/potentially preventable (P/PP) deaths resulting from any blunt trauma mechanism in the pediatric population than in the adult population (19.6% vs. 48.4%, p < 0.001). Amongst the pediatric population, P/PP traumatic brain injury (TBI) were more common in the youngest age range (age 0-5) vs. the older (6-12 years) pediatric and adolescent (13-17 years) patients.

CONCLUSION

Our results identify areas of opportunities for improving pediatric trauma care. Although the overall P/PP death rate is lower in the pediatric population than the adult, opportunities for improving initial acute care, particularly TBI, exist.

Epidemiological and Accounting Analysis of Ground Ambulance Whole Blood Transfusion

INTRODUCTION

In October 2017, the American Association of Blood Bankers (AABB; Bethesda, Maryland USA) approved a petition to allow low-titer group O whole blood as a standard product without the need for a waiver. Around that time, a few Texas, USA-based Emergency Medical Services (EMS) systems incorporated whole blood into their ground ambulances. The purpose of this project was to describe the epidemiology of ground ambulance patients that received a prehospital whole blood transfusion. The secondary aim of this project was to report an accounting analysis of these ground ambulance prehospital whole blood programs.

METHODS

The dataset came from the Harris County Emergency Service District 48 Fire Department (HCESD 48; Harris County, Texas USA) and San Antonio Fire Department (SAFD; San Antonio, Texas USA) whole blood Quality Assurance/Quality Improvement (QA/QI) databases from September 2017 through December 2018. The primary outcome of this study was the prehospital transfusion indication. The secondary outcome was the projected cost per life saved during the first 10 years of the prehospital whole blood initiative.

RESULTS

Of 58 consecutive prehospital whole blood administrations, the team included all 58 cases. Hemorrhagic shock from a non-traumatic etiology accounted for 46.5% (95% CI, 34.3%-59.2%) of prehospital whole blood recipients. In the non-traumatic hemorrhagic shock cohort, gastrointestinal hemorrhage was the underlying etiology of hemorrhagic shock in 66.7% (95% CI, 47.8%-81.4%) of prehospital whole blood transfusion recipients. The projected average cost to save a life in Year 10 was US$5,136.51 for the combined cohort, US$4,512.69 for HCESD 48, and US$5,243.72 for SAFD EMS.

CONCLUSION

This retrospective analysis of ground ambulance patients that receive prehospital whole blood transfusion found that non-traumatic etiology accounted for 46.5% (95% CI, 34.3%-59.2%) of prehospital whole blood recipients. Additionally, the accounting analysis suggests that by Year 10 of a ground ambulance whole blood transfusion program, the average cost to save a life will be approximately US$5,136.51.

Give the trauma patient what they bleed, when and where they need it: establishing a comprehensive regional system of resuscitation based on patient need utilizing cold-stored, low-titer O+ whole blood

BACKGROUND

Despite countless advancements in trauma care a survivability gap still exists in the prehospital setting. Military studies clearly identify hemorrhage as the leading cause of potentially survivable prehospital death. Shifting resuscitation from the hospital to the point of injury has shown great promise in decreasing mortality among the severely injured.

MATERIALS AND METHODS

Our regional trauma network (Southwest Texas Regional Advisory Council) developed and implemented a multiphased approach toward facilitating remote damage control resuscitation. This approach required placing low-titer O+ whole blood (LTO+ WB) at helicopter emergency medical service bases, transitioning hospital-based trauma resuscitation from component therapy to the use of whole blood, modifying select ground-based units to carry and administer whole blood at the scene of an accident, and altering the practices of our blood bank to support our new initiative. In addition, we had to provide information and training to an entire large urban emergency medical system regarding changes in policy.

RESULTS

Through a thorough, structured program we were able to successfully implement point-of-injury resuscitation with LTO+ WB. Preliminary evaluation of our first 25 patients has shown a marked decrease in mortality compared to our historic rate using component therapy or crystalloid solutions. Additionally, we have had zero transfusion reactions or seroconversions.

CONCLUSION

Transfusion at the scene within minutes of injury has the potential to save lives. As our utilization expands to our outlying network we expect to see a continued decrease in mortality among significantly injured trauma patients.

Is prehospital blood transfusion effective and safe in haemorrhagic trauma patients? A systematic review and meta-analysis

BACKGROUND

Life-threatening haemorrhage accounts for 40% mortality in trauma patients worldwide. After bleeding control is achieved, circulating volume must be restored. Early in-hospital transfusion of blood components is already proven effective, but the scientific proof for the effectiveness of prehospital blood-component transfusion (PHBT) in trauma patients is still unclear.

OBJECTIVE

To systematically review the evidence for effectiveness and safety of PHBT to haemorrhagic trauma patients.

METHODS

CINAHL, Cochrane, EMBASE, and Pubmed were searched in the period from 1988 until August 1, 2018. Meta-analysis was performed for matched trauma patients receiving PHBT with the primary outcomes 24-hour mortality and long-term mortality. Secondary outcome measure was adverse events as a result of PHBT.

RESULTS

Trauma patients who received PHBT with simultaneous use of packed red blood cells (pRBCs) and plasma showed a statistically significant reduction in long-term mortality (OR = 0.51; 95% CI, 0.36-0.71; P < 0.0001) but no difference in 24-hour mortality (OR = 0.47, 95% CI, 0.17-1.34; P = 0.16). PHBT with individual use of pRBCs showed no difference in long-term mortality (OR = 1.18; 95% CI, 0.93-1.49; P =  0.17) or 24-hour mortality (OR = 0.92; 95% CI, 0.46-1.85; P =  0.82). In a total of 1341 patients who received PHBT, 14 adverse events were reported 1.04%, 95% CI 0.57-1.75%.

CONCLUSIONS

PHBT with simultaneous use of both pRBCs and plasma resulted in a significant reduction in the odds for long-term mortality. However, based on mainly poor quality evidence no hard conclusion can be drawn about a possible survival benefit for haemorrhagic trauma patients receiving PHBT. Overall, PHBT is safe but results of currently ongoing randomised controlled trials have to be awaited to demonstrate a survival benefit.

STUDY TYPE

Systematic review and meta-analysis.

Damage Control Resuscitation in polytrauma patient

Haemorrhagic shock is one of the main causes of mortality in severe polytrauma patients. To increase the survival rates, a combined strategy of treatment known as Damage Control has been developed. The aims of this article are to analyse the actual concept of Damage Control Resuscitation and its three treatment levels, describe the best transfusion strategy, and approach the acute coagulopathy of the traumatic patient as an entity. The potential changes of this therapeutic strategy over the coming years are also described.

The design of an adaptive clinical trial to evaluate the efficacy of platelets stored at low temperature in surgical patients

BACKGROUND

Storage of platelets at 4°C compared with 22°C may increase both hemostatic activity and storage duration; however, the maximum duration of cold storage is unknown. We report the design of an innovative, prospective, randomized, Bayesian adaptive, "duration finding" clinical trial to evaluate the efficacy and maximum duration of storage of platelets at 4°C.

METHODS

Patients undergoing cardiac surgery and requiring platelet transfusions will be enrolled. Patients will be randomized to receive platelets stored at 22°C up to 5 days or platelets stored at 4°C up to 5 days, 10 days, or 15 days. Longer durations of cold storage will only be used if shorter durations at 4°C appear noninferior to standard storage, based on a four-level clinical hemostatic efficacy score with a NIM of a half level. A Bayesian linear model is used to estimate the hemostatic efficacy of platelet transfusions based on the actual duration of storage at 4°C.

RESULTS

The type I error rate, if platelets stored at 4°C are inferior, is 0.0247 with an 82% probability of early stopping for futility. With a maximum sample size of 1,500, the adaptive trial design has a power of over 90% to detect noninferiority and a high probability of correctly identifying the maximum duration of storage at 4°C that is noninferior to 22°C.

CONCLUSION

An adaptive, duration-finding trial design will generate Level I evidence and allow the determination of the maximum duration platelet storage at 4°C that is noninferior to standard storage at 22°C, with respect to hemostatic efficacy. The adaptive trial design helps to ensure that longer cold storage durations are only explored once substantial supportive data are available for the shorter duration(s) and that the trial stops early if continuation is likely to be futile.

Effects of platelet-sparing leukocyte reduction and agitation methods on in vitro measures of hemostatic function in cold-stored whole blood

BACKGROUND

Agitation of platelet units stored at room temperature is performed routinely to maintain platelet function, and leukoreduction of blood products is the standard of care in many countries to reduce immune consequences of transfusion. The effect of agitation and leukoreduction on whole blood stored at 4°C requires investigation, as reductions in hemostatic capacity of whole blood may reduce its efficacy in treating trauma-induced coagulopathy and platelet dysfunction. We hypothesize that agitation of whole blood will not affect hemostatic function and that leukoreduction will reduce hemostatic function of whole blood.

METHODS

In this in vitro randomized controlled study, 21 units of leukoreduced and 20 nonleukoreduced whole blood units were each randomly assigned into four agitation groups. Hemostatic parameters were measured using viscoelastic assays (rotational thromboelastometry-Extrinsic Screening Test (ROTEM-EXTEM) and thromboelastography (TEG) platelet mapping), impedance aggregometry (agonists-adenosine phosphate, arachidonic acid, thrombin receptor activating peptide, and collagen), and a thrombin generation assay from these whole blood units before and after filtration and on 0, 5, 10, and 15 days of storage at 4°C.

RESULTS

Leukoreduction compared to nonleukoreduction reduced platelet concentration on Day 0. Viscoelastic measures and thrombin generation parameters revealed significant reduction in hemostatic function between the leukoreduced units and the nonleukoreduced units at a few time points. Leukoreduced units consistently demonstrated reduced platelet aggregation compared to the nonleukoreduced units. Agitation methods did not significantly affect any of the hemostatic parameters examined.

CONCLUSIONS

Leukoreduction of whole blood with a platelet-sparing filter caused a moderate but significant reduction in some measures of whole blood hemostatic function most evident early in storage. The benefits of leukoreduction should be weighed against the potential reduced hemostatic function of leukoreduced units. Agitation of whole blood is not required to maintain hemostatic function.

LEVEL OF EVIDENCE

In vitro randomized controlled trial, level 1.

Intravenous administration of synthetic platelets (SynthoPlate) in a mouse liver injury model of uncontrolled hemorrhage improves hemostasis

BACKGROUND

Clinical resuscitative treatment of traumatic hemorrhage involves transfusion of RBC, platelets and plasma in controlled ratios. However, use of such blood components, especially platelets, present many challenges including availability, portability, contamination risks, and short shelf-life, which limit the use of platelet transfusions outside of large trauma centers such as remote civilian hospitals and austere prehospital settings. This has prompted significant research in platelet substitutes that may resolve the above issues while providing platelet-mimetic hemostatic action. In this framework, we have developed a synthetic platelet surrogate, SynthoPlate, by integrative decoration of platelet function mimetic peptides on a biocompatible lipid nanovesicle platform. We have previously demonstrated hemostatic capability of SynthoPlate in correcting tail-bleeding time in thrombocytopenic mice. Building on this, we hypothesized that SynthoPlate transfusion would decrease bleeding in a murine model of acute hemorrhagic shock.

METHODS

A validated model of uncontrolled intraperitoneal hemorrhage, via liver laceration was used to induce hemorrhagic shock in mice. SynthoPlate, control (unmodified) particles, and normal saline were administered as pretreatment and recue infusions to mice undergoing liver laceration and evaluated for hemostatic benefit by determining differences in blood loss and monitoring real-time hemodynamic data.

RESULTS

Pretreatment SynthoPlate transfusion resulted in significant reduction of blood loss following hemorrhage, compared with control particles or normal saline treatment (0.86 ± 0.16 g control particles [CP] vs. 0.84 ± 0.13 g normal saline [NS] vs. 0.68 ± 0.09 g SynthoPlate, p < 0.005). SynthoPlate transfused mice demonstrated improved hemodynamics taking significantly longer to develop post-injury hypotension (168.3 ± 106.6 seconds CP vs. 137 ± 58 seconds NS vs. 546.7 ± 329.8 seconds SynthoPlate, p < 0.05). SynthoPlate infusion following liver laceration, that is, rescue transfusion, also resulted in a significant decrease in blood loss (0.89 ± 0.17 g CP vs. 0.92 ± 0.19 g NS vs. 0.69 ± 0.18 g SynthoPlate, p < 0.05).

CONCLUSION

Transfusion of SynthoPlate particles reduces blood loss in a murine model of liver injury, and SynthoPlates may represent a viable transfusion product for the mitigation of blood loss in acute, severe hemorrhagic shock.

Blood transfusion management in the severely bleeding military patient

PURPOSE OF REVIEW

Hemorrhage remains the primary cause of preventable death on the battlefield and in civilian trauma. Hemorrhage control is multifactorial and starts with point-of-injury care. Surgical hemorrhage control and time from injury to surgery is paramount; however, interventions in the prehospital environment and perioperative period affect outcomes. The purpose of this review is to understand concepts and strategies for successful management of the bleeding military patient. Understanding the life-threatening nature of coagulopathy of trauma and implementing strategies aimed at full spectrum hemorrhage management from point of injury to postoperative care will result in improved outcomes in patients with life-threatening bleeding.

RECENT FINDINGS

Timely and appropriate therapies impact survival. Blood product resuscitation for life-threatening hemorrhage should either be with whole blood or a component therapy strategy that recapitulates the functionality of whole blood. The US military has transfused over 10 000 units of whole blood since the beginning of the wars in Iraq and Afghanistan. The well recognized therapeutic benefits of whole blood have pushed this therapy far forward into prehospital care in both US and international military forces. Multiple hemostatic adjuncts are available that are likely beneficial to the bleeding military patient; and other products and techniques are under active investigation.

SUMMARY

Lessons learned in the treatment of combat casualties will likely continue to have positive impact and influence and the management of hemorrhage in the civilian trauma setting.

Recommendations on RBC Transfusion in Critically Ill Children With Nonlife-Threatening Bleeding or Hemorrhagic Shock From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the recommendations and supporting literature for RBC transfusions in critically ill children with bleeding developed by the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

The panel of 38 experts developed evidence-based and, when evidence was lacking, expert-based clinical recommendations as well as research priorities for RBC transfusions in critically ill children. The bleeding subgroup included five experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 2017. Agreement was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Transfusion and Anemia Expertise Initiative Consensus Conference experts developed a total of six recommendations focused on transfusion in the critically ill child with acute bleeding. In critically ill children with nonlife-threatening bleeding, we recommend giving a RBC transfusion for a hemoglobin concentration less than 5 g/dL, and be considered for a hemoglobin concentration between 5 and 7 g/dL. In critically ill children with hemorrhagic shock, we suggest that RBCs, plasma and platelets transfusion ratio between 2:1:1 to 1:1:1 until the bleeding is no longer life-threatening. We recommend future studies to develop physiologic and laboratory measures to indicate the need for RBC transfusions, and to determine if goal directed hemostatic resuscitation improves survival. Finally, we recommend future studies to determine if low titer group O whole blood is more efficacious and safe compared with reconstituted whole blood in children with hemorrhagic shock.

CONCLUSIONS

The Transfusion and Anemia Expertise Initiative Consensus Conference developed pediatric specific recommendations regarding RBC transfusion management in the critically ill child with acute bleeding, as well as recommendations to help guide future research priorities.

Vox Sanguinis International Forum on the use of prehospital blood products and pharmaceuticals in the treatment of patients with traumatic haemorrhage

While specific practices and transported blood products vary around the world, most of the respondents in this International Forum transported at least one blood product for the transfusion to bleeding patients en route to the hospital. The most commonly carried product was RBCs, while the use of whole blood will likely increase given the recent reports of its successful use in the civilian setting, and because of the change in the AABB's Standards regulating its use. It will be interesting to see if plasma use in the prehospital setting becomes more widely used given today's enhanced appreciated of the coagulopathy of trauma and plasma's beneficial effect in reversing it, and if blood products are transported to the scene of injury by more vehicles, that is, not just predominantly in helicopters. It was not surprising that TXA is being widely administered as close to the time of injury as possible given its potential benefit in these patients. This International Forum highlights the importance of focusing attention on prehospital transfusion management with a need to further high‐quality research in this area to guide optimal resuscitation strategies.