Evidence-Based and Clinically Relevant Outcomes for Hemorrhage Control Trauma Trials

Association of freeze-dried plasma with 24-h mortality among trauma patients at risk for hemorrhage

BACKGROUND

Blood products form the cornerstone of contemporary hemorrhage control but are limited resources. Freeze-dried plasma (FDP), which contains coagulation factors, is a promising adjunct in hemostatic resuscitation. We explore the association between FDP alone or in combination with other blood products on 24-h mortality.

STUDY DESIGN AND METHODS

This is a secondary data analysis from a cross-sectional prospective observational multicenter study of adult trauma patients in the Western Cape of South Africa. We compare mortality among trauma patients at risk of hemorrhage in three treatment groups: Blood Products only, FDP + Blood Products, and FDP only. We apply inverse probability of treatment weighting and fit a multivariable Cox proportional hazards model to assess the hazard of 24-h mortality.

RESULTS

Four hundred and forty-eight patients were included, and 55 (12.2%) died within 24 h of hospital arrival. Compared to the Blood Products only group, we found no difference in 24-h mortality for the FDP + Blood Product group (p = .40) and a lower hazard of death for the FDP only group (hazard = 0.38; 95% CI, 0.15-1.00; p = .05). However, sensitivity analyses showed no difference in 24-h mortality across treatments in subgroups with moderate and severe shock, early blood product administration, and accounting for immortal time bias.

CONCLUSION

We found insufficient evidence to conclude there is a difference in relative 24-h mortality among trauma patients at risk for hemorrhage who received FDP alone, blood products alone, or blood products with FDP. There may be an adjunctive role for FDP in hemorrhagic shock resuscitation in settings with significantly restricted access to blood products.

The Role of Whole Blood Hemostatic Resuscitation in Bleeding Geriatric Trauma Patients

INTRODUCTION

Whole blood (WB) has recently gained increased popularity as an adjunct to the resuscitation of hemorrhaging civilian trauma patients. We aimed to assess the nationwide outcomes of using WB as an adjunct to component therapy (CT) versus CT alone in resuscitating geriatric trauma patients.

METHODS

We performed a 5-y (2017-2021) retrospective analysis of the Trauma Quality Improvement Program. We included geriatric (age, ≥65 y) trauma patients presenting with hemorrhagic shock (shock index >1) and requiring at least 4 units of packed red blood cells in 4 h. Patients with severe head injuries (head Abbreviated Injury Scale ≥3) and transferred patients were excluded. Patients were stratified into WB-CT versus CT only. Primary outcomes were 6-h, 24-h, and in-hospital mortality. Secondary outcomes were major complications. Multivariable regression analysis was performed, adjusting for potential confounding factors.

RESULTS

A total of 1194 patients were identified, of which 141 (12%) received WB. The mean ± standard deviation age was 74 ± 7 y, 67.5% were male, and 83.4% had penetrating injuries. The median [interquartile range] Injury Severity Score was 19 [13-29], with no difference among study groups (P = 0.059). Overall, 6-h, 24-h, and in-hospital mortality were 16%, 23.1%, and 43.6%, respectively. On multivariable regression analysis, WB was independently associated with reduced 24-h (odds ratio, 0.62 [0.41-0.94]; P = 0.024), and in-hospital mortality (odds ratio, 0.60 [0.40-0.90]; P = 0.013), but not with major complications (odds ratio, 0.78 [0.53-1.15]; P = 0.207).

CONCLUSIONS

Transfusion of WB as an adjunct to CT is associated with improved early and overall mortality in geriatric trauma patients presenting with severe hemorrhage. The findings from this study are clinically important, as this is an essential first step in prioritizing the selection of WB resuscitation for geriatric trauma patients presenting with hemorrhagic shock.

Preferential whole blood transfusion during the early resuscitation period is associated with decreased mortality and transfusion requirements in traumatically injured patients

Introduction

Whole blood (WB) transfusion represents a promising resuscitation strategy for trauma patients. However, a paucity of data surrounding the optimal incorporation of WB into resuscitation strategies persists. We hypothesized that traumatically injured patients who received a greater proportion of WB compared with blood product components during their resuscitative efforts would have improved early mortality outcomes and decreased transfusion requirements compared with those who received a greater proportion of blood product components.

Methods

Retrospective review from our Level 1 trauma center of trauma patients during their initial resuscitation (2019-2022) was performed. WB to packed red blood cell ratios (WB:RBC) were assigned to patients based on their respective blood product resuscitation at 1, 2, 3, and 24 hours from presentation. Multivariable regression models were constructed to assess the relationship of WB:RBC to 4 and 24-hour mortality, and 24-hour transfusion requirements.

Results

390 patients were evaluated (79% male, median age of 33 years old, 48% penetrating injury rate, and a median Injury Severity Score of 27). Overall mortality at 4 hours was 9%, while 24-hour mortality was 12%. A significantly decreased 4-hour mortality was demonstrated in patients who displayed a WB:RBC≥1 at 1 hour (5.9% vs. 12.3%; OR 0.17, p=0.015), 2 hours (5.5% vs. 13%; OR 0.16, p=0.019), and 3 hours (5.5% vs. 13%, OR 0.18, p<0.01), while a decreased 24-hour mortality was displayed in those with a WB:RBC≥1 at 24 hours (7.9% vs. 14.6%, OR 0.21, p=0.01). Overall 24-hour transfusion requirements were significantly decreased within the WB:RBC≥1 cohort (12.1 units vs. 24.4 units, p<0.01).

Conclusion

Preferential WB transfusion compared with a balanced transfusion strategy during the early resuscitative period was associated with a lower 4 and 24-hour mortality, as well as decreased 24-hour transfusion requirements, in trauma patients. Future prospective studies are warranted to determine the optimal use of WB in trauma.

Level of evidence

Level III/therapeutic.

A review and analysis of outcomes in randomized clinical trials of plasma transfusion in patients with bleeding or for the prevention of bleeding: The BEST collaborative study

BACKGROUND

Previous systematic reviews have revealed an inconsistency of outcome definitions as a major barrier in providing evidence-based guidance for the use of plasma transfusion to prevent or treat bleeding. We reviewed and analyzed outcomes in randomized controlled trials (RCTs) to provide a methodology for describing and classifying outcomes.

STUDY DESIGN AND METHODS

RCTs involving transfusion of plasma published after 2000 were identified from a prior review (Yang 2012) and combined with an updated systematic literature search of multiple databases (July 1, 2011 to January 17, 2023). Inclusion of publications, data extraction, and risk of bias assessments were performed in duplicate. (PROSPERO registration number is: CRD42020158581).

RESULTS

In total, 5579 citations were identified in the new systematic search and 22 were included. Six additional trials were identified from the previous review, resulting in a total of 28 trials: 23 therapeutic and five prophylactic studies. An increasing number of studies in the setting of major bleeding such as in cardiovascular surgery and trauma were identified. Eighty-seven outcomes were reported with a mean of 11 (min-max. 4-32) per study. There was substantial variation in outcomes used with a preponderance of surrogate measures for clinical effect such as laboratory parameters and blood usage.

CONCLUSION

There is an expanding literature on plasma transfusion to inform guidelines. However, considerable heterogeneity of reported outcomes constrains comparisons. A core outcome set should be developed for plasma transfusion studies. Standardization of outcomes will motivate better study design, facilitate comparison, and improve clinical relevance for future trials of plasma transfusion.

Rapid clearing CT-001 restored hemostasis in mice with coagulopathy induced by activated protein C

BACKGROUND

Activated protein C (APC) is one of the mechanisms contributing to coagulopathy, which is associated with high mortality. The counteraction of the APC pathway could help ameliorate bleeding. However, patients also transform frequently from a hemorrhagic state to a prothrombotic state at a later time. Therefore, a prohemostatic therapeutic intervention should take this thrombotic risk into consideration.

OBJECTIVES

CT-001 is a novel factor VIIa (FVIIa) with enhanced activity and desialylated N-glycans for rapid clearance. We assessed CT-001 clearance in multiple species and its ability to reverse APC-mediated coagulopathic blood loss.

METHODS

The N-glycans on CT-001 were characterized by liquid chromatography-mass spectrometry. Three species were used to evaluate the pharmacokinetics of the molecule. The potency and efficacy of CT-001 under APC pathway-induced coagulopathic conditions were assessed by coagulation assays and bleeding models.

RESULTS

The N-glycosylation sites of CT-001 had high occupancy of desialylated N-glycans. CT-001 exhibited 5 to 16 times higher plasma clearance in human tissue factor knockin mice, rats, and cynomolgus monkeys than wildtype FVIIa. CT-001 corrected the activated partial thromboplastin time and thrombin generation of coagulopathic plasma to normal in in vitro studies. In an APC-mediated saphenous vein bleeding model, 3 mg/kg of CT-001 reduced bleeding time in comparison with wildtype FVIIa. The correction of bleeding by CT-001 was also observed in a coagulopathic tail amputation severe hemorrhage mouse model. The efficacy of CT-001 is independent of the presence of tranexamic acid, and the combination of CT-001 and tranexamic acid does not lead to increased thrombogenicity.

CONCLUSION

CT-001 corrected APC pathway-mediated coagulopathic conditions in preclinical studies and could be a potentially safe and effective procoagulant agent for addressing APC-mediated bleeding.

Walking blood bank: a plan to ensure self-sufficiency in an era of blood shortage

Mass casualty incidents and massive transfusion requirements continue to plague the USA with hemorrhage remaining the number one cause of death in trauma. The unfortunate reality of numerous mass shootings in Southwest Texas has led to the need for a way in which to provide blood during these events as rapidly as it is required. Multiple agencies within the Southwest Texas system have united to help provide this life-saving blood to people when they need it most. This effort began with the development of a system for safe, efficient, and now widespread use of whole blood in the region. After demonstrating the success of delivering large quantities of blood during the Uvalde shooting, we have begun to develop a walking blood bank that is similar to what the miliary uses on the battlefield. The concept behind this initiative is to have a cohort of whole blood donors who are preselected to join the program which is now dubbed 'Heroes in Arms'. These donors will be called upon to donate whole blood during a massive transfusion event. Their blood will be rapidly screened prior to transfusion to the patient. This blood will still undergo the normal rigorous testing and, should any potentially transmissible diseases by discovered post-transfusion, the individual who received that product will be treated accordingly. Given the low rate of transmissible disease among this preselected population, combined with rapid screening prior to transfusion, the risk of a person receiving a transmissible disease is insignificant in comparison to the benefit of having blood to transfuse during hemorrhage. This model is a promising collaborative effort to provide in a timely and sufficient blood product in cases of major need which will consequently minimize the number of traumatically injured civilian patients who die from hemorrhage.

The Golden Hour of Casualty Care: Rapid Handoff to Surgical Team is Associated With Improved Survival in War-injured US Service Members

OBJECTIVE

To examine time from injury to initiation of surgical care and association with survival in US military casualties.

BACKGROUND

Although the advantage of trauma care within the "golden hour" after an injury is generally accepted, evidence is scarce.

METHODS

This retrospective, population-based cohort study included US military casualties injured in Afghanistan and Iraq, January 2007 to December 2015, alive at initial request for evacuation with maximum abbreviated injury scale scores ≥2 and documented 30-day survival status after injury. Interventions: (1) handoff alive to the surgical team, and (2) initiation of first surgery were analyzed as time-dependent covariates (elapsed time from injury) using sequential Cox proportional hazards regression to assess how intervention timing might affect mortality. Covariates included age, injury year, and injury severity.

RESULTS

Among 5269 patients (median age, 24 years; 97% males; and 68% battle-injured), 728 died within 30 days of injury, 68% within 1 hour, and 90% within 4 hours. Only handoffs within 1 hour of injury and the resultant timely initiation of emergency surgery (adjusted also for prior advanced resuscitative interventions) were significantly associated with reduced 24-hour mortality compared with more delayed surgical care (adjusted hazard ratios: 0.34; 95% CI: 0.14-0.82; P = 0.02; and 0.40; 95% CI: 0.20-0.81; P = 0.01, respectively). In-hospital waits for surgery (mean: 1.1 hours; 95% CI; 1.0-1.2) scarcely contributed ( P = 0.67).

CONCLUSIONS

Rapid handoff to the surgical team within 1 hour of injury may reduce mortality by 66% in US military casualties. In the subgroup of casualties with indications for emergency surgery, rapid handoff with timely surgical intervention may reduce mortality by 60%. To inform future research and trauma system planning, findings are pivotal.

The proteomic and metabolomic signatures of isolated and polytrauma traumatic brain injury

BACKGROUND

The interactions of polytrauma, shock, and traumatic brain injury (TBI) on thromboinflammatory responses remain unclear and warrant investigation as we strive towards personalized medicine in trauma. We hypothesized that comprehensive omics characterization of plasma would identify unique metabolic and thromboinflammatory pathways following TBI.

METHODS

Patients were categorized as TBI vs Non-TBI, and stratified into Polytrauma or minimally injured. Discovery 'omics was employed to quantify the top differently expressed proteins and metabolites of TBI and Non-TBI patient groups.

RESULTS

TBI compared to Non-TBI showed gene enrichment in coagulation/complement cascades and neuronal markers. TBI was associated with elevation in glycolytic metabolites and conjugated bile acids. Division into isolated TBI vs polytrauma showed further distinction of proteomic and metabolomic signatures.

CONCLUSION

Identified mediators involving in neural inflammation, blood brain barrier disruption, and bile acid building leading to TBI associated coagulopathy offer suggestions for follow up mechanistic studies to target personalized interventions.

Incompatible plasma transfusion is not associated with increased mortality in civilian trauma patients

BACKGROUND

The introduction of low titer group O whole blood (LTOWB) that contains potentially ABO-incompatible plasma and the increasing use of group A plasma, due to shortages of AB plasma, in trauma patients whose ABO group is unknown could put the recipients of incompatible plasma at risk of increased morbidity and mortality. This study evaluated civilian trauma patient outcomes following receipt of incompatible plasma.

METHODS

One trauma center's patient contributions to three multicenter studies of different trauma resuscitation strategies was analyzed; these patients were separated into two groups based on receipt of only compatible plasma versus receipt of any quantity of incompatible plasma. Multivariate analysis was performed to determine if receipt of incompatible plasma was associated with 24-hour or 30-day mortality.

RESULTS

There were 347 patients eligible for this secondary analysis with 167 recipients of only compatible plasma and 180 recipients of incompatible plasma. The two groups were well matched demographically and on both prehospital and hospital arrival vital signs. The median (IQR) volume of incompatible plasma received by these patients was 684 ml (342, 1229). There was not a significant difference between the groups in 24-hour and 30-day mortality, nor in in-hospital or intensive care unit lengths of stay. In the Cox proportional-hazards regression model for both 24-hour and 30-day survival, receipt of incompatible plasma was not independently predictive of either mortality endpoint.

CONCLUSION

Receipt of incompatible plasma was not independently associated with increased mortality in trauma patients. Prospective studies are needed to confirm these findings.

Tissue plasminogen activator challenge thrombelastography is the most accurate assay in predicting the need for massive transfusion in hypotensive trauma patients

BACKGROUND

Tissue plasminogen activator (tPA) added to thrombelastography (TEG) detects hyperfibrinolysis by measuring clot lysis at 30 min (tPA-challenge-TEG). We hypothesize that tPA-challenge-TEG is a better predictor of massive transfusion (MT) than existing strategies in trauma patients with hypotension.

METHODS

Trauma activation patients (TAP, 2014-2020) with 1) systolic blood pressure <90 mmHg (early) or 2) those who arrived normotensive but developed hypotension within 1H postinjury (delayed) were analyzed. MT was defined as >10 RBC U/6H postinjury or death within 6H after ≥1 RBC unit. Area under the receiver operating characteristics curves were used to compare predictive performance. Youden index determined optimal cutoffs.

RESULTS

tPA-challenge-TEG was the best predictor of MT in the early hypotension subgroup (N = 212) with positive (PPV) and negative predictive values (NPV) of 75.0%, and 77.6%, respectively. tPA-challenge-TEG was a better predictor of MT than all but TASH (PPV = 65.0%, NPV = 93.3%) in the delayed hypotension group (N = 125).

CONCLUSIONS

The tPA-challenge-TEG is the most accurate predictor of MT in trauma patients arriving hypotensive and offers early recognition of MT in patients with delayed hypotension.

Nationwide analysis of prehospital tranexamic acid for trauma demonstrates systematic bias in adherence to treatment guidelines: a retrospective cohort study

BACKGROUND

Prehospital (PH) tranexamic acid (TXA) improves survival from trauma haemorrhage. Injury mechanism, physiology, and sex demographics vary with patient age. The authors hypothesised that these factors influence TXA guideline compliance and examined national trends in PH use to identify any systematic biases in bleeding management.

MATERIALS AND METHODS

The UK Trauma Audit and Research Network data for TXA eligible patients admitted to major trauma centres were divided into two cohorts: 2013-2015 ( n =32 072) and 2017-2019 ( n =14 974). Patients were stratified by PH, emergency department or no TXA use. Logistic regression models explored interaction between PH variables and TXA administration. Results are presented as odds ratios with a 95% CI.

RESULTS

PH TXA use increased from 8% to 27% over time ( P <0.001). Only 3% of eligible patients who fell less than 2 m received PH TXA versus 63% with penetrating injuries ( P <0.001). Older patients eligible for PH TXA were less likely to receive it compared to younger patients [≥65 years old: 590 (13%) vs. <65 years old: 3361 (33%), P <0.001]. There was a significant interaction between age and sex with fewer older women receiving PH TXA. In shocked patients, one third of females compared to a fifth of men did not receive TXA ( P <0.001). There was a decrease in PH TXA use as age increased ( P <0.001).

CONCLUSIONS

Despite a threefold increase in use, treatment guidance for PH TXA is not universally applied. Older people, women, and patients with low energy injury mechanisms appear to be systematically under treated. Training and education for PH providers should address these potential treatment biases.

Achieving balanced transfusion early in critically bleeding trauma patients: an observational study exploring the effect of attending trauma surgical presence during resuscitation

Background

After 15 years of damage control resuscitation (DCR), studies still report high mortality rates for critically bleeding trauma patients. Adherence to massive hemorrhage protocols (MHPs) based on a 1:1:1 ratio of plasma, platelets, and red blood cells (RBCs) as part of DCR has been shown to improve outcomes. We wanted to assess MHP use in the early (6 hours from admission), critical phase of DCR and its impact on mortality. We hypothesized that the presence of an attending trauma surgeon during all MHP activations from 2013 would contribute to improving institutional resuscitation strategies and patient outcomes.

Methods

We conducted a retrospective analysis of all trauma patients receiving ≥10 RBCs within 6 hours of admission and included in the institutional trauma registry between 2009 and 2019. The cohort was divided in period 1 (P1): January 2009-August 2013, and period 2 (P2): September 2013-December 2019 for comparison of outcomes.

Results

A total of 141 patients were included, 81 in P1 and 60 in P2. Baseline characteristics were similar between the groups for Injury Severity Score, lactate, Glasgow Coma Scale, and base deficit. Patients in P2 received more plasma (16 units vs. 12 units; p<0.01), resulting in a more balanced plasma:RBC ratio (1.00 vs. 0.74; p<0.01), and platelets:RBC ratio (1.11 vs. 0.92; p<0.01). All-cause mortality rates decreased from P1 to P2, at 6 hours (22% to 8%; p=0.03), at 24 hours (36% vs 13%; p<0.01), and at 30 days (48% vs 30%, p=0.03), respectively. A stepwise logistic regression model predicted an OR of 0.27 (95% CI 0.08 to 0.93) for dying when admitted in P2.

Conclusions

Achieving balanced transfusion rates at 6 hours, facilitated by the presence of an attending trauma surgeon at all MHP activations, coincided with a reduction in all-cause mortality and hemorrhage-related deaths in massively transfused trauma patients at 6 hours, 24 hours, and 30 days.

Level of evidence

IV.

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.

Assessment of ethynylestradiol-3-sulfate on coagulation, metabolism, and survival in pigs with traumatic hemorrhage

BACKGROUND

The beneficial effects of estrogens on survival from hemorrhage have been suggested in some preclinical models. This study investigated the effects of ethynylestradiol-3-sulfate (EE-3-S) on coagulation, metabolism and survival in pigs following traumatic hemorrhage.

METHODS

Twenty-six pigs were randomized into: normal saline group (NS, n = 10), EE-3-S group (EE-3, n = 11) groups, and no resuscitation group (NR, n = 5). Femur fracture was performed in each pig's left leg, followed by hemorrhage of 55% of estimated blood volume and a 10-minute shock period. Afterward, pigs were resuscitated with a small volume of either NS alone (4 mL/kg) or EE-3-S with NS (1 mL/kg at concentration of 1 mg/mL, plus NS solution of 3 mL/kg). Pigs in NR group were not resuscitated with any fluid. All pigs were then monitored for 6 hours or until death, with hemodynamics and survival times recorded. Blood samples were taken during the study for measurements of oxygen metabolism (oxygen delivery, extraction, and consumption) and coagulation function (using Rotem with Extem reagents).

RESULTS

All baseline measurements were similar among the three groups. In the NS group, femur fracture and hemorrhage immediately reduced mean arterial pressure (MAP, 74 ± 3 mm Hg to 44 ± 4 mm Hg) and increased heart rate (97 ± 5 bpm to 218 ± 14 bpm, both p < 0.05). Similar changes in MAP and heart rate were observed in the EE-3 and NR groups. There were no differences observed in changes of Rotem ® measurements or oxygen metabolism among the groups during the study. At 6 hours, four pigs in NS, four pigs in EE-3-S, and two pigs in the NR group survived to the end of the study. The mean survival times were similar among the NS (212 ± 43 minutes), EE-3 (212 ± 39 minutes), and NR (223 ± 63 minutes) groups ( p = 0.9845).

CONCLUSION

Following severe traumatic hemorrhage, hypotensive resuscitation with EE-3-S did not impact coagulation, metabolism, or survival in pigs.

Data-Driven Blood Transfusion Thresholds for Severely Injured Patients During Blood Shortages

INTRODUCTION

Crises like the COVID-19 pandemic create blood product shortages. Patients requiring transfusions are placed at risk and institutions may need to judiciously administer blood during massive blood transfusions protocols (MTP). The purpose of this study is to provide data-driven guidance for the modification of MTP when the blood supply is severely limited.

METHODS

This is a retrospective cohort study of 47 Level I and II trauma centers (TC) within a single healthcare system whose patients received MTP from 2017 to 2019. All TC used a unifying MTP protocol for balanced blood product transfusions. The primary outcome was mortality as a function of volume of blood transfused and age. Hemoglobin thresholds and measures of futility were also estimated. Risk-adjusted analyses were performed using multivariable and hierarchical regression to account for confounders and hospital variation.

RESULTS

Proposed MTP maximum volume thresholds for three age groupings are as follows: 60 units for ages 16-30 y, 48 units for ages 31-55 y, and 24 units for >55 y. The range of mortality under the transfusion threshold was 30%-36% but doubled to 67-77% when the threshold was exceeded. Hemoglobin concentration differences relative to survival were clinically nonsignificant. Prehospital measures of futility were prehospital cardiac arrest and nonreactive pupils. In hospital risk factors of futility were mid-line shift on brain CT and cardiopulmonary arrest.

CONCLUSIONS

Establishing MTP threshold practices under blood shortage conditions, such as the COVID pandemic, could sustain blood availability by following relative thresholds for MTP use according to age groups and key risk factors.

Balanced resuscitation and earlier mortality end points: bayesian post hoc analysis of the PROPPR trial

Introduction

The Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial failed to demonstrate a mortality difference for hemorrhaging patients receiving a balanced (1:1:1) vs a 1:1:2 resuscitation at 24 hours and 30 days. Recent guidelines recommend earlier mortality end points for hemorrhage-control trials, and the use of contemporary statistical methods. The aim of this post hoc analysis of the PROPPR trial was to evaluate the impact of a balanced resuscitation strategy at early resuscitation time points using a Bayesian analytical framework.

Methods

Bayesian hierarchical models were created to assess mortality differences at the 1, 3, 6, 12, 18, and 24 hours time points between study cohorts. Posterior probabilities and Bayes factors were calculated for each time point.

Results

A 1:1:1 resuscitation displayed a 96%, 99%, 94%, 92%, 96%, and 94% probability for mortality benefit at 1, 3, 6, 12, 18, and 24 hours, respectively, when compared with a 1:1:2 approach. Associated Bayes factors for each respective time period were 21.2, 142, 14.9, 11.4, 26.4, and 15.5, indicating 'strong' to 'decisive' supporting evidence in favor of balanced transfusions.

Conclusion

This analysis provides evidence in support that a 1:1:1 resuscitation has a high probability of mortality benefit when compared with a 1:1:2 strategy, especially at the newly defined more proximate time points during the resuscitative period. Researchers should consider using Bayesian approaches, along with more proximate end points when assessing hemorrhage-related mortality, for the analysis of future clinical trials.

Level of evidence

Level III/Therapeutic.

Whole Blood Resuscitation and Association with Survival in Injured Patients with an Elevated Probability of Mortality

BACKGROUND

Low-titer group O whole blood (LTOWB) resuscitation is becoming common in both military and civilian settings and may represent the ideal resuscitation intervention. We sought to characterize the safety and efficacy of LTOWB resuscitation relative to blood component resuscitation.

STUDY DESIGN

A prospective, multicenter, observational cohort study was performed using 7 trauma centers. Injured patients at risk of massive transfusion who required both blood transfusion and hemorrhage control procedures were enrolled. The primary outcome was 4-hour mortality. Secondary outcomes included 24-hour and 28-day mortality, achievement of hemostasis, death from exsanguination, and the incidence of unexpected survivors.

RESULTS

A total of 1,051 patients in hemorrhagic shock met all enrollment criteria. The cohort was severely injured with >70% of patients requiring massive transfusion. After propensity adjustment, no significant 4-hour mortality difference across LTOWB and component patients was found (relative risk [RR] 0.90, 95% CI 0.59 to 1.39, p = 0.64). Similarly, no adjusted mortality differences were demonstrated at 24 hours or 28 days for the enrolled cohort. When patients with an elevated prehospital probability of mortality were analyzed, LTOWB resuscitation was independently associated with a 48% lower risk of 4-hour mortality (relative risk [RR] 0.52, 95% CI 0.32 to 0.87, p = 0.01) and a 30% lower risk of 28-day mortality (RR 0.70, 95% CI 0.51 to 0.96, p = 0.03).

CONCLUSIONS

Early LTOWB resuscitation is safe but not independently associated with survival for the overall enrolled population. When patients were selected with an elevated probability of mortality based on prehospital injury characteristics, LTOWB was independently associated with a lower risk of mortality starting at 4 hours after arrival through 28 days after injury.

Establishing a core outcomes set for massive transfusion: An Eastern Association for the Surgery of Trauma modified Delphi method consensus study

BACKGROUND

The management of severe hemorrhage has changed significantly over recent decades, resulting in a heterogeneous description of diagnosis, treatment, and outcomes in the literature, which is not suitable for data pooling. Therefore, we sought to develop a core outcome set (COS) to help guide future massive transfusion (MT) research and overcome the challenge of heterogeneous outcomes reporting.

METHODS

Massive transfusion content experts were invited to participate in a modified Delphi study. For Round 1, participants submitted a list of proposed core outcomes. In subsequent rounds, panelists used a 9-point Likert scale to score proposed outcomes for importance. Core outcomes consensus was defined as >85% of scores receiving 7 to 9 and <15% of scores receiving 1 to 3. Feedback and aggregate data were shared between rounds.

RESULTS

From an initial panel of 16 experts, 12 (75%) completed three rounds of deliberation to reevaluate variables not achieving predefined consensus criteria. A total of 64 items were considered, with 4 items achieving consensus for inclusion as core outcomes: blood products received in the first 6 hours, 6-hour mortality, time to mortality, and 24-hour mortality.

CONCLUSION

Through an iterative survey consensus process, content experts have defined a COS to guide future MT research. This COS will be a valuable tool for researchers seeking to perform new MT research and will allow future trials to generate data that can be used in pooled analyses with enhanced statistical power.

LEVEL OF EVIDENCE

Diagnostic Test or Criteria; Level V.

Cryoprecipitate for the treatment of life-threatening hemorrhage in children

BACKGROUND

Hypofibrinogenemia is an important risk factor for poor outcomes in children with severe bleeding. There is a paucity of data on the impact of cryoprecipitate transfusion on outcomes in pediatric patients with life-threatening hemorrhage (LTH).

STUDY DESIGN AND METHODS

This secondary analysis of a multicenter prospective observational study of children with LTH investigated subjects who were categorized by receipt of cryoprecipitate during their resuscitation and according to the etiology of their bleeding: trauma, operative, and medical. Bivariate analysis was performed to identify variables associated with 6-h, 24-h, and 28-day mortality. Cox Hazard regression models were generated to adjust for potential confounders.

RESULTS

Cryoprecipitate was transfused to 33.9% (152/449) of children during LTH. The median (Interquartile range) time to cryoprecipitate administration was 108 (47-212) minutes. Children in the cryoprecipitate group were younger, more often female, with higher BMI and pre-LTH PRISM score and lower platelet counts. After adjusting for PRISM score, bleeding etiology, age, sex, RBC volume, platelet volume, antifibrinolytic use and cardiac arrest, cryoprecipitate administration was independently associated with lower 6-h mortality, Hazard Ratio (95% CI), 0.41 (0.19-0.89), (p = 0.02) and 24-h mortality, Hazard Ratio (95% CI), 0.46 (0.24-0.89), (p = 0.02).

CONCLUSION

Cryoprecipitate transfusion to children with LTH was associated with reduced early mortality. A prospective randomized trial is needed to determine if cryoprecipitate can improve outcomes in children with LTH.

Efficacy and Safety of Early Administration of 4-Factor Prothrombin Complex Concentrate in Patients With Trauma at Risk of Massive Transfusion: The PROCOAG Randomized Clinical Trial

Importance

Optimal transfusion strategies in traumatic hemorrhage are unknown. Reports suggest a beneficial effect of 4-factor prothrombin complex concentrate (4F-PCC) on blood product consumption.

Objective

To investigate the efficacy and safety of 4F-PCC administration in patients at risk of massive transfusion.

Design, Setting, and Participants

Double-blind, randomized, placebo-controlled superiority trial in 12 French designated level I trauma centers from December 29, 2017, to August 31, 2021, involving consecutive patients with trauma at risk of massive transfusion. Follow-up was completed on August 31, 2021.

Interventions

Intravenous administration of 1 mL/kg of 4F-PCC (25 IU of factor IX/kg) vs 1 mL/kg of saline solution (placebo). Patients, investigators, and data analysts were blinded to treatment assignment. All patients received early ratio-based transfusion (packed red blood cells:fresh frozen plasma ratio of 1:1 to 2:1) and were treated according to European traumatic hemorrhage guidelines.

Main Outcomes and Measures

The primary outcome was 24-hour all blood product consumption (efficacy); arterial or venous thromboembolic events were a secondary outcome (safety).

Results

Of 4313 patients with the highest trauma level activation, 350 were eligible for emergency inclusion, 327 were randomized, and 324 were analyzed (164 in the 4F-PCC group and 160 in the placebo group). The median (IQR) age of participants was 39 (27-56) years, Injury Severity Score was 36 (26-50 [major trauma]), and admission blood lactate level was 4.6 (2.8-7.4) mmol/L; prehospital arterial systolic blood pressure was less than 90 mm Hg in 179 of 324 patients (59%), 233 patients (73%) were men, and 226 (69%) required expedient hemorrhage control. There was no statistically or clinically significant between-group difference in median (IQR) total 24-hour blood product consumption (12 [5-19] U in the 4F-PCC group vs 11 [6-19] U in the placebo group; absolute difference, 0.2 U [95% CI, -2.99 to 3.33]; P = .72). In the 4F-PCC group, 56 patients (35%) presented with at least 1 thromboembolic event vs 37 patients (24%) in the placebo group (absolute difference, 11% [95% CI, 1%-21%]; relative risk, 1.48 [95% CI, 1.04-2.10]; P = .03).

Conclusions and Relevance

Among patients with trauma at risk of massive transfusion, there was no significant reduction of 24-hour blood product consumption after administration of 4F-PCC, but thromboembolic events were more common. These findings do not support systematic use of 4F-PCC in patients at risk of massive transfusion.

Trial Registration

ClinicalTrials.gov Identifier: NCT03218722.

Modern Statistical Methods for the Surgeon Scientist: The Clash of Frequentist versus Bayesian Paradigms

The practice of evidence-based medicine is the result of a multitude of research and trials aimed toward improving health-care outcomes. An understanding of the associated data remains paramount toward optimizing patient outcomes. Medical statistics commonly revolve around frequentist concepts that are convoluted and nonintuitive for nonstatisticians. Within this article, we will discuss frequentist statistics, their limitations, as well as introduce Bayesian statistics as an alternative approach for data interpretation. By doing so, we intend to highlight the importance of correct statistical interpretations through clinically relevant examples while providing a deeper understanding of the underlying philosophies of frequentist and Bayesian statistics.

Patients with severe polytrauma: management and imaging protocols

Traumatic injuries can be severe and complex, requiring the coordinated efforts of a multidisciplinary team. Imaging tests play a fundamental role in rapid and accurate diagnosis. In particular, whole-body computed tomography (CT) has become a key tool. There are different CT protocols depending on the patient's condition; whereas dose-optimized protocols can be used in stable patients, time/precision protocols prioritizing speed at the cost of delivering higher doses of radiation should be used in more severe patients. In unstable patients who cannot be examined by CT, X-rays of the chest and pelvis and FAST or e-FAST ultrasound studies, although less sensitive than CT, enable the detection of situations that require immediate treatment. This article reviews the imaging techniques and CT protocols for the initial hospital workup for patients with multiple trauma.

Association of red blood cells and plasma transfusion versus red blood cell transfusion only with survival for treatment of major traumatic hemorrhage in prehospital setting in England: a multicenter study

BACKGROUND

In-hospital acute resuscitation in trauma has evolved toward early and balanced transfusion resuscitation with red blood cells (RBC) and plasma being transfused in equal ratios. Being able to deliver this ratio in prehospital environments is a challenge. A combined component, like leukocyte-depleted red cell and plasma (RCP), could facilitate early prehospital resuscitation with RBC and plasma, while at the same time improving logistics for the team. However, there is limited evidence on the clinical benefits of RCP.

OBJECTIVE

To compare prehospital transfusion of combined RCP versus RBC alone or RBC and plasma separately (RBC + P) on mortality in trauma bleeding patients.

METHODS

Data were collected prospectively on patients who received prehospital transfusion (RBC + thawed plasma/Lyoplas or RCP) for traumatic hemorrhage from six prehospital services in England (2018-2020). Retrospective data on patients who transfused RBC from 2015 to 2018 were included for comparison. The association between transfusion arms and 24-h and 30-day mortality, adjusting for age, injury mechanism, age, prehospital heart rate and blood pressure, was evaluated using generalized estimating equations.

RESULTS

Out of 970 recruited patients, 909 fulfilled the study criteria (RBC + P = 391, RCP = 295, RBC = 223). RBC + P patients were older (mean age 42 vs 35 years for RCP and RBC), and 80% had a blunt injury (RCP = 52%, RBC = 56%). RCP and RBC + P were associated with lower odds of death at 24-h, compared to RBC alone (adjusted odds ratio [aOR] 0.69 [95%CI: 0.52; 0.92] and 0.60 [95%CI: 0.32; 1.13], respectively). The lower odds of death for RBC + P and RCP vs RBC were driven by penetrating injury (aOR 0.22 [95%CI: 0.10; 0.53] and 0.39 [95%CI: 0.20; 0.76], respectively). There was no association between RCP or RBC + P with 30-day survival vs RBC.

CONCLUSION

Prehospital plasma transfusion for penetrating injury was associated with lower odds of death at 24-h compared to RBC alone. Large trials are needed to confirm these findings.

Systemic hemostatic agents initiated in trauma patients in the pre-hospital setting: a systematic review

Purpose

The effect of systemic hemostatic agents initiated during pre-hospital care of severely injured patients with ongoing bleeding or traumatic brain injury (TBI) remains controversial. A systematic review and meta-analysis was therefore conducted to assess the effectiveness and safety of systemic hemostatic agents as an adjunctive therapy in people with major trauma and hemorrhage or TBI in the context of developing the Italian National Institute of Health guidelines on major trauma integrated management.

Methods

PubMed, Embase, and Cochrane Library databases were searched up to October 2021 for studies that investigated pre-hospital initiated treatment with systemic hemostatic agents. The certainty of evidence was evaluated with the Grading of Recommendations Assessment, Development, and Evaluation approach, and the quality of each study was determined with the Cochrane risk-of-bias tool. The primary outcome was overall mortality, and secondary outcomes included cause-specific mortality, health-related quality of life, any adverse effects and blood product use, hemorrhage expansion, and patient-reported outcomes.

Results

Five trials of tranexamic acid (TXA) met the inclusion criteria for this meta-analysis. With a high certainty of evidence, when compared to placebo TXA reduced mortality at 24 h (relative risk = 0.83, 95% confidence interval = 0.73–0.94) and at 1 month among trauma patients (0.91, 0.85–0.97). These results depend on the subgroup of patients with significant hemorrhage because in the subgroup of TBI there are no difference between TXA and placebo. TXA also reduced bleeding death and multiple organ failure whereas no difference in health-related quality of life.

Conclusion

Balancing benefits and harms, TXA initiated in the pre-hospital setting can be used for patients experiencing major trauma with significant hemorrhage since it reduces the risk of mortality at 24 h and one month with no difference in terms of adverse effects when compared to placebo. Considering the subgroup of severe TBI, no difference in mortality rate was found at 24 h and one month. These results highlight the need to conduct future studies to investigate the role of other systemic hemostatic agents in the pre-hospital settings.

The epidemiology and outcomes of prolonged trauma care (EpiC) study: methodology of a prospective multicenter observational study in the Western Cape of South Africa

Background

Deaths due to injuries exceed 4.4 million annually, with over 90% occurring in low-and middle-income countries. A key contributor to high trauma mortality is prolonged trauma-to-treatment time. Earlier receipt of medical care following an injury is critical to better patient outcomes. Trauma epidemiological studies can identify gaps and opportunities to help strengthen emergency care systems globally, especially in lower income countries, and among military personnel wounded in combat. This paper describes the methodology of the “Epidemiology and Outcomes of Prolonged Trauma Care (EpiC)” study, which aims to investigate how the delivery of resuscitative interventions and their timeliness impacts the morbidity and mortality outcomes of patients with critical injuries in South Africa.

Methods

The EpiC study is a prospective, multicenter cohort study that will be implemented over a 6-year period in the Western Cape, South Africa. Data collected will link pre- and in-hospital care with mortuary reports through standardized clinical chart abstraction and will provide longitudinal documentation of the patient’s clinical course after injury. The study will enroll an anticipated sample of 14,400 injured adults. Survival and regression analysis will be used to assess the effects of critical early resuscitative interventions (airway, breathing, circulatory, and neurologic) and trauma-to-treatment time on the primary 7-day mortality outcome and secondary mortality (24-h, 30-day) and morbidity outcomes (need for operative interventions, secondary infections, and organ failure).

Discussion

This study is the first effort in the Western Cape of South Africa to build a standardized, high-quality, multicenter epidemiologic trauma dataset that links pre- and in-hospital care with mortuary data. In high-income countries and the U.S. military, the introduction of trauma databases and registries has led to interventions that significantly reduce post-injury death and disability. The EpiC study will describe epidemiology trends over time, and it will enable assessments of how trauma care and system processes directly impact trauma outcomes to ultimately improve the overall emergency care system.

Trial Registration: Not applicable as this study is not a clinical trial.

Association of Early Norepinephrine Administration With 24-Hour Mortality Among Patients With Blunt Trauma and Hemorrhagic Shock

IMPORTANCE

Hemorrhagic shock is a common cause of preventable death after injury. Vasopressor administration for patients with blunt trauma and hemorrhagic shock is often discouraged.

OBJECTIVE

To evaluate the association of early norepinephrine administration with 24-hour mortality among patients with blunt trauma and hemorrhagic shock.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, multicenter, observational cohort study used data from 3 registries in the US and France on all consecutive patients with blunt trauma from January 1, 2013, to December 31, 2018. Patients were alive on admission with hemorrhagic shock, defined by prehospital or admission systolic blood pressure less than 100 mm Hg and evidence of hemorrhage (ie, prehospital or resuscitation room transfusion of packed red blood cells, receipt of emergency treatment for hemorrhage control, transfusion of >10 units of packed red blood cells in the first 24 hours, or death from hemorrhage). Blunt trauma was defined as any exposure to nonpenetrating kinetic energy, collision, or deceleration. Statistical analysis was performed from January 15, 2021, to February 22, 2022.

EXPOSURE

Continuous administration of norepinephrine in the prehospital environment or resuscitation room prior to hemorrhage control, according to European guidelines.

MAIN OUTCOMES AND MEASURES

The primary outcome was 24-hour mortality, and the secondary outcome was in-hospital mortality. The average treatment effect (ATE) of early norepinephrine administration on 24-hour mortality was estimated according to the Rubin causal model. Inverse propensity score weighting and the doubly robust approach with 5 distinct analytical strategies were used to determine the ATE.

RESULTS

A total of 52 568 patients were screened for inclusion, and 2164 patients (1508 men [70%]; mean [SD] age, 46 [19] years; median Injury Severity Score, 29 [IQR, 17-36]) presented with acute hemorrhage and were included. A total of 1497 patients (69.1%) required emergency hemorrhage control, 128 (5.9%) received a prehospital transfusion of packed red blood cells, and 543 (25.0%) received a massive transfusion. Norepinephrine was administered to 1498 patients (69.2%). The 24-hour mortality rate was 17.8% (385 of 2164), and the in-hospital mortality rate was 35.6% (770 of 2164). None of the 5 analytical strategies suggested any statistically significant association between norepinephrine administration and 24-hour mortality, with ATEs ranging from -4.6 (95% CI, -11.9 to 2.7) to 2.1 (95% CI, -2.1 to 6.3), or between norepinephrine administration and in-hospital mortality, with ATEs ranging from -1.3 (95% CI, -9.5 to 6.9) to 5.3 (95% CI, -2.1 to 12.8).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that early norepinephrine infusion was not associated with 24-hour or in-hospital mortality among patients with blunt trauma and hemorrhagic shock. Randomized clinical trials that study the effect of early norepinephrine administration among patients with trauma and hypotension are warranted to further assess whether norepinephrine is safe for patients with hemorrhagic shock.

Early identification of bleeding in trauma patients: external validation of traumatic bleeding scores in the Swiss Trauma Registry

BACKGROUND

Early identification of bleeding at the scene of an injury is important for triage and timely treatment of injured patients and transport to an appropriate facility. The aim of the study is to compare the performance of different bleeding scores.

METHODS

We examined data from the Swiss Trauma Registry for the years 2015-2019. The Swiss Trauma Registry includes patients with major trauma (injury severity score (ISS) ≥ 16 and/or abbreviated injury scale (AIS) head ≥ 3) admitted to any level-one trauma centre in Switzerland. We evaluated ABC, TASH and Shock index (SI) scores, used to predict massive transfusion (MT) and the BATT score and used to predict death from bleeding. We evaluated the scores when used prehospital and in-hospital in terms of discrimination (C-Statistic) and calibration (calibration slope). The outcomes were early death within 24 h and the receipt of massive transfusion (≥ 10 Red Blood cells (RBC) units in the first 24 h or ≥ 3 RBC units in the first hour).

RESULTS

We examined data from 13,222 major trauma patients. There were 1,533 (12%) deaths from any cause, 530 (4%) early deaths within 24 h, and 523 (4%) patients who received a MT (≥ 3 RBC within the first hour). In the prehospital setting, the BATT score had the highest discrimination for early death (C-statistic: 0.86, 95% CI 0.84-0.87) compared to the ABC score (0.63, 95% CI 0.60-0.65) and SI (0.53, 95% CI 0.50-0.56), P < 0.001. At hospital admission, the TASH score had the highest discrimination for MT (0.80, 95% CI 0.78-0.82). The positive likelihood ratio for early death were superior to 5 for BATT, ABC and TASH. The negative likelihood ratio for early death was below 0.1 only for the BATT score.

CONCLUSIONS

The BATT score accurately estimates the risk of early death with excellent performance, low undertriage, and can be used for prehospital treatment decision-making. Scores predicting MT presented a high undertriage rate. The outcome MT seems not appropriate to stratify the risk of life-threatening bleeding.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT04561050 . Registered 15 September 2020.

Balancing enrollment and mortality in hemorrhage control trials: A secondary analysis of the PROPPR trial

BACKGROUND

Designing clinical trials on hemorrhage control requires carefully balancing the need for high enrollment numbers with the need of focusing on the sickest patients. The Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial enrolled patients within 2 hours of arrival to the emergency department for a trial of injured patients at risk for massive transfusion. We conducted a secondary analysis to determine how time-to-randomization affected patient outcomes and the balance between enrollment and mortality.

METHODS

Patients from the Pragmatic Randomized Optimal Platelet and Plasma Ratios trial were compared based on 30-minute time to randomization intervals. Outcomes included 24-hour and 30-day mortality, time to hemostasis, adverse events, and operative procedures. Additional analyses were conducted based on treatment arm allocation, mechanism of injury, and variation in start time (arrival vs. randomization).

RESULTS

Randomization within 30 minutes of arrival was associated with higher injury severity (median Injury Severity Score, 29 vs. 26 overall; p < 0.01), lower systolic blood pressure (median, 91 vs. 102 mm Hg overall; p < 0.01), and increased penetrating mechanism (50% vs. 47% overall; p < 0.01). Faster time-to-randomization was associated with increased 24-hour (20% for 0- to 30 minute entry, 9% for 31-minute to 60-minute entry, 10% for 61-minute to 90-minute entry, 0% for 91-minute to 120-minute entry; p < 0.01) and 30-day mortality (p < 0.01). There were no significant associations between time-to-randomization and adverse event occurrence, operative interventions, or time to hemostasis.

CONCLUSION

Increasing time to randomization in this large multicenter randomized trial was associated with increased survival. Fastest randomization (within 0-30 minutes) was associated with highest 24-hour and 30-day mortality, but only 57% of patients were enrolled within this timeframe. Only 3% of patients were enrolled within the last 30-minute window (91-120 minutes), with none of them dying within the first 24 hours. For a more optimal balance between enrollment and mortality, investigators should consider shortening the time to randomization when planning future clinical trials of hemorrhage control interventions.

LEVEL OF EVIDENCE

Prognostic and Epidemiologic; Level II.

Multicentre observational study on practice of prehospital management of hypotensive trauma patients: the SPITFIRE study protocol

INTRODUCTION

Major haemorrhage after injury is the leading cause of preventable death for trauma patients. Recent advancements in trauma care suggest damage control resuscitation (DCR) should start in the prehospital phase following major trauma. In Italy, Helicopter Emergency Medical Services (HEMS) assist the most complex injuries and deliver the most advanced interventions including DCR. The effect size of DCR delivered prehospitally on survival remains however unclear.

METHODS AND ANALYSIS

This is an investigator-initiated, large, national, prospective, observational cohort study aiming to recruit >500 patients in haemorrhagic shock after major trauma. We aim at describing the current practice of hypotensive trauma management as well as propose the creation of a national registry of patients with haemorrhagic shock.

PRIMARY OBJECTIVE

the exploration of the effect size of the variation in clinical practice on the mortality of hypotensive trauma patients. The primary outcome measure will be 24 hours, 7-day and 30-day mortality. Secondary outcomes include: association of prehospital factors and survival from injury to hospital admission, hospital length of stay, prehospital and in-hospital complications, hospital outcomes; use of prehospital ultrasound; association of prehospital factors and volume of first 24-hours blood product administration and evaluation of the prevalence of use, appropriateness, haemodynamic, metabolic and effects on mortality of prehospital blood transfusions.

INCLUSION CRITERIA

age >18 years, traumatic injury attended by a HEMS team including a physician, a systolic blood pressure <90 mm Hg or weak/absent radial pulse and a confirmed or clinically likely diagnosis of major haemorrhage. Prehospital and in-hospital variables will be collected to include key times, clinical findings, examinations and interventions. Patients will be followed-up until day 30 from admission. The Glasgow Outcome Scale Extended will be collected at 30 days from admission.

ETHICS AND DISSEMINATION

The study has been approved by the Ethics committee 'Comitato Etico di Area Vasta Emilia Centro'. Data will be disseminated to the scientific community by abstracts submitted to international conferences and by original articles submitted to peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04760977.

Determining Resuscitation Outcomes in Combat Casualties: Design of the Deployed Hemostatic Emergency Resuscitation Of Traumatic Exsanguinating Shock (Deployed HEROES) Study

BACKGROUND

During the course of the recent conflicts, the recommendations for resuscitation practices have evolved, but there has been no comprehensive comparative effectiveness study of these resuscitation strategies. The objective of this study was to describe the development and study design of the Deployed Hemostatic Emergency Resuscitation Of Traumatic Exsanguinating Shock (Deployed HEROES) Study- the first comprehensive analysis of military resuscitation practices in the deployed environment from October 2001 to October 2019.

METHODS

This retrospective cohort study uses the DoD Trauma Registry, Armed Services Blood Program database, and Military Trauma Mortality Review, while abstractors will use Theater Medical Data Store and Web Interface Patient Records to collect transfusion timing data. This study includes patients, who received blood products or died before receiving blood, treated at US military medical treatment facilities. The primary endpoints are survival at 6 hours, 24 hours, and 30 days post-injury. Secondary outcomes include infection, renal dysfunction, pulmonary dysfunction, and thromboembolic event. Exposure will be defined by blood product transfusion. Study groups will be frequency-matched. Cox proportional hazards will compare patients who received WFWB, LTOWB, or only component therapy, while using adjustment for type of blood product transfused as a time-dependent covariate. Multilevel mixed-effects logistic regression will determine the effect of incompatible plasma in LTOWB.

RESULTS

An analysis plan for the Deployed HEROES study was developed with the aim of minimizing bias.

CONCLUSIONS

This study will inform the optimal resuscitation strategies, which will potentially have a substantial impact on combat mortality. If whole blood is found to be the optimal transfusion strategy, this finding will be crucial in future operating environments involving dispersed medical assets. These results will provide critical information necessary for combat casualty care guidelines.

LEVEL OF EVIDENCE

Level III.

The effectiveness and cost-effectiveness of resuscitative endovascular balloon occlusion of the aorta (REBOA) for trauma patients with uncontrolled torso haemorrhage: study protocol for a randomised clinical trial (the UK-REBOA trial)

BACKGROUND

Haemorrhage is the most common cause of preventable death after injury. REBOA is a novel technique whereby a percutaneously inserted balloon is deployed in the aorta, providing a relatively quick means of temporarily controlling haemorrhage and augmenting cerebral and coronary perfusion, until definitive control of haemorrhage can be attained. The aim of the UK-REBOA trial is to establish the clinical and cost-effectiveness of a policy of standard major trauma centre treatment plus REBOA, as compared with standard major trauma centre treatment alone, for the management of uncontrolled torso haemorrhage caused by injury.

METHODS

Pragmatic, Bayesian, group-sequential, randomised controlled trial, performed in 16 major trauma centres in England. We aim to randomise 120 injured patients with suspected exsanguinating haemorrhage to either standard major trauma centre care plus REBOA or standard major trauma centre care alone. The primary clinical outcome is 90-day mortality. Secondary clinical outcomes include 3-h, 6-h, and 24-h mortality; in-hospital mortality; 6-month mortality; length of stay (in hospital and intensive care unit); 24-h blood product use; need for haemorrhage control procedure (operation or angioembolisation); and time to commencement of haemorrhage control procedure (REBOA, operation, or angioembolisation). The primary economic outcome is lifetime incremental cost per QALY gained, from a health and personal social services perspective.

DISCUSSION

This study, which is the first to randomly allocate patients to treatment with REBOA or standard care, will contribute high-level evidence on the clinical and cost-effectiveness of REBOA in the management of trauma patients with exsanguinating haemorrhage and will provide important data on the feasibility of implementation of REBOA into mainstream clinical practice.

TRIAL REGISTRATION

ISRCTN16184981.

Advances in hemorrhage control resuscitation

PURPOSE OF REVIEW

Despite significant advances in trauma management over the last twenty years, uncontrolled hemorrhage remains the leading cause of preventable death in trauma. We review recent changes affecting hemorrhage control resuscitation.

RECENT FINDINGS

Early blood product usage has become well established as a standard of care in trauma hemorrhage control. To enable this, low titer group A liquid plasma and group O whole blood are increasingly utilized. Single donor apheresis platelets have now replaced pooled donor platelets in the USA and are often pathogen reduced, which has implications for trauma resuscitation. Further work is examining timing and dosing of tranexamic acid and the debate in factor concentrate usage in trauma induced coagulopathy continues to evolve. The 'Stop the bleed' campaign has highlighted how important the use of hemostatic dressings are in hemorrhage control, as too is the expanded use of endovascular aortic occlusion. We highlight the ongoing research into desmopressin use and the undetermined significance of ionized calcium levels in trauma. Finally, we discuss our own hospital experience with coagulation testing and the paucity of evidence of improved outcomes with viscoelastic testing.

SUMMARY

Improving trauma coagulopathy diagnostics and hemorrhage control are vital if we are to decrease the mortality associated with trauma.

Transfusion Ratios and Deficits in Injured Children With Life-Threatening Bleeding

OBJECTIVES

To assess the impact of plasma and platelet ratios and deficits in injured children with life-threatening bleeding.

DESIGN

Secondary analysis of the MAssive Transfusion epidemiology and outcomes In Children study dataset, a prospective observational study of children with life-threatening bleeding events.

SETTING

Twenty-four childrens hospitals in the United States, Canada, and Italy.

PATIENTS

Injured children 0-17 years old who received greater than 40 mL/kg total blood products over 6 hours or were transfused under activation of massive transfusion protocol.

INTERVENTION/EXPOSURE

Weight-adjusted blood product volumes received during the bleeding event were recorded. Plasma:RBC ratio (plasma/RBC weight-adjusted volume in mL/kg) and platelet:RBC ratio (platelet/RBC weight-adjusted volume in mL/kg) were analyzed. Plasma deficit was calculated as RBC mL/kg - plasma mL/kg; platelet deficit was calculated as RBC mL/kg - platelet mL/kg.

MEASUREMENTS AND MAIN RESULTS

Of 191 patients analyzed, median (interquartile range) age was 10 years (5-15 yr), 61% were male, 61% blunt mechanism, and median (interquartile range) Injury Severity Score was 29 (24-38). After adjusting for Pediatric Risk of Mortality score, cardiac arrest, use of vasoactive medications, and blunt mechanism, a high plasma:RBC ratio (> 1:2) was associated with improved 6-hour survival compared with a low plasma:RBC ratio (odds ratio [95% CI] = 0.12 [0.03-0.52]; p = 0.004). Platelet:RBC ratio was not associated with survival. After adjusting for age, Pediatric Risk of Mortality score, cardiac arrest, and mechanism of injury, 6-hour and 24-hour mortality were increased in children with greater plasma deficits (10% and 20% increased odds of mortality for every 10 mL/kg plasma deficit at 6 hr [p = 0.04] and 24 hr [p = 0.01], respectively); 24-hour mortality was increased in children with greater platelet deficits (10% increased odds of 24-hr mortality for every 10 mL/kg platelet deficit [p = 0.02)]).

CONCLUSIONS

In injured children, balanced resuscitation may improve early survival according to this hypothesis generating study. Multicenter clinical trials are needed to assess whether clinicians should target ratios and deficits as optimal pediatric hemostatic resuscitation practice.

Application of Alginate-Based Hydrogels in Hemostasis

Hemorrhage, as a common trauma injury and clinical postoperative complication, may cause serious damage to the body, especially for patients with huge blood loss and coagulation dysfunction. Timely and effective hemostasis and avoidance of bleeding are of great significance for reducing body damage and improving the survival rate and quality of life of patients. Alginate is considered to be an excellent hemostatic polymer-based biomaterial due to its excellent biocompatibility, biodegradability, non-toxicity, non-immunogenicity, easy gelation and easy availability. In recent years, alginate hydrogels have been more and more widely used in the medical field, and a series of hemostatic related products have been developed such as medical dressings, hemostatic needles, transcatheter interventional embolization preparations, microneedles, injectable hydrogels, and hemostatic powders. The development and application prospects are extremely broad. This manuscript reviews the structure, properties and history of alginate, as well as the research progress of alginate hydrogels in clinical applications related to hemostasis. This review also discusses the current limitations and possible future development prospects of alginate hydrogels in hemostatic applications.

Developing a National Trauma Research Action Plan: Results from the prehospital and mass casualty research Delphi survey

BACKGROUND

The National Academies of Sciences, Engineering, and Medicine 2016 trauma system report recommended a National Trauma Research Action Plan to strengthen and guide future trauma research. To address this recommendation, 11 expert panels completed a Delphi survey process to create a comprehensive research agenda, spanning the continuum of trauma care. We describe the gap analysis and high-priority research questions generated from the National Trauma Research Action Plan panel on prehospital and mass casualty trauma care.

METHODS

We recruited interdisciplinary national experts to identify gaps in the prehospital and mass casualty trauma evidence base and generate prioritized research questions using a consensus-driven Delphi survey approach. We included military and civilian representatives. Panelists were encouraged to use the Patient/Population, Intervention, Compare/Control, and Outcome format to generate research questions. We conducted four Delphi rounds in which participants generated key research questions and then prioritized the questions on a 9-point Likert scale to low-, medium-, and high-priority items. We defined consensus as ≥60% agreement on the priority category and coded research questions using a taxonomy of 118 research concepts in 9 categories.

RESULTS

Thirty-one interdisciplinary subject matter experts generated 490 research questions, of which 433 (88%) reached consensus on priority. The rankings of the 433 questions were as follows: 81 (19%) high priority, 339 (78%) medium priority, and 13 (3%) low priority. Among the 81 high-priority questions, there were 46 taxonomy concepts, including health systems of care (36 questions), interventional clinical trials and comparative effectiveness (32 questions), mortality as an outcome (30 questions), prehospital time/transport mode/level of responder (24 questions), system benchmarks (17 questions), and fluid/blood product resuscitation (17 questions).

CONCLUSION

This Delphi gap analysis of prehospital and mass casualty care identified 81 high-priority research questions to guide investigators and funding agencies for future trauma research.

Whole blood at the tip of the spear: A retrospective cohort analysis of warm fresh whole blood resuscitation versus component therapy in severely injured combat casualties

BACKGROUND

Death from uncontrolled hemorrhage occurs rapidly, particularly among combat casualties. The US military has used warm fresh whole blood during combat operations owing to clinical and operational exigencies, but published outcomes data are limited. We compared early mortality between casualties who received warm fresh whole blood versus no warm fresh whole blood.

METHODS

Casualties injured in Afghanistan from 2008 to 2014 who received ≥2 red blood cell containing units were reviewed using records from the Joint Trauma System Role 2 Database. The primary outcome was 6-hour mortality. Patients who received red blood cells solely from component therapy were categorized as the non-warm fresh whole blood group. Non- warm fresh whole blood patients were frequency-matched to warm fresh whole blood patients on identical strata by injury type, patient affiliation, tourniquet use, prehospital transfusion, and average hourly unit red blood cell transfusion rates, creating clinically unique strata. Multilevel mixed effects logistic regression adjusted for the matching, immortal time bias, and other covariates.

RESULTS

The 1,105 study patients (221 warm fresh whole blood, 884 non-warm fresh whole blood) were classified into 29 unique clinical strata. The adjusted odds ratio of 6-hour mortality was 0.27 (95% confidence interval 0.13-0.58) for the warm fresh whole blood versus non-warm fresh whole blood group. The reduction in mortality increased in magnitude (odds ratio = 0.15, P = .024) among the subgroup of 422 patients with complete data allowing adjustment for seven additional covariates. There was a dose-dependent effect of warm fresh whole blood, with patients receiving higher warm fresh whole blood dose (>33% of red blood cell-containing units) having significantly lower mortality versus the non-warm fresh whole blood group.

CONCLUSION

Warm fresh whole blood resuscitation was associated with a significant reduction in 6-hour mortality versus non-warm fresh whole blood in combat casualties, with a dose-dependent effect. These findings support warm fresh whole blood use for hemorrhage control as well as expanded study in military and civilian trauma settings.

Outcome measures used in clinical research evaluating prehospital blood component transfusion in traumatically injured bleeding patients: A systematic review

BACKGROUND

Trial outcomes should be relevant to all stakeholders and allow assessment of interventions' efficacy and safety at appropriate timeframes. There is no consensus regarding outcome measures in the growing field of prehospital trauma transfusion research. Harmonization of future clinical outcome reporting is key to facilitate interstudy comparisons and generate cohesive, robust evidence to guide practice. The objective of this study was to evaluate outcome measures reported in prehospital trauma transfusion trials.

METHODS

Data Sources, Eligibility Criteria, Participants, and InterventionsWe conducted a scoping systematic review to identify the type, number, and definitions of outcomes reported in randomized controlled trials, and prospective and retrospective observational cohort studies investigating prehospital blood component transfusion in adult and pediatric patients with traumatic hemorrhage. Electronic database searching of PubMed, Embase, Web of Science, Cochrane, OVID, clinical trials.gov, and the Transfusion Evidence Library was completed in accordance with Preferred Reporting Items for Meta-analyses guidelines.Study Appraisal and Synthesis MethodsTwo review authors independently extracted outcome data. Unique lists of salutogenic (patient-reported health and wellbeing outcomes) and nonsalutogenic focused outcomes were established.

RESULTS

A total of 3,471 records were identified. Thirty-four studies fulfilled the inclusion criteria: 4 military (n = 1,566 patients) and 30 civilian (n = 14,398 patients), all between 2000 and 2020. Two hundred twelve individual non-patient-reported outcomes were identified, which collapsed into 20 outcome domains with varied definitions and timings. All primary outcomes measured effectiveness, rather than safety or complications. Sixty-nine percent reported mortality, with 11 different definitions. No salutogenic outcomes were reported.

CONCLUSION

There is heterogeneity in outcome reporting and definitions, an absence of patient-reported outcome, and an emphasis on clinical effectiveness rather than safety or adverse events in prehospital trauma transfusion trials. We recommend stakeholder consultation and a Delphi process to develop a clearly defined minimum core outcome set for prehospital trauma transfusion trials.

LEVEL OF EVIDENCE

Scoping systematic review, level III.

Blood component use and injury characteristics of acute trauma patients arriving from the scene of injury or as transfers to a large, mature US Level 1 trauma center serving a large, geographically diverse region

BACKGROUND

Advanced trauma care demands the timely availability of hemostatic blood products, posing special challenges for regional systems in geographically diverse areas. We describe acute trauma blood use by transfer status and injury characteristics at a large regional Level 1 trauma center.

STUDY DESIGN AND METHODS

We reviewed Harborview Medical Center (HMC) Trauma Registry, Transfusion Service, and electronic medical records on acute trauma patients for demographics, injury patterns, blood use, and in-hospital mortality, 2011-2019.

RESULTS

Among 47,471 patients (mean age 45.2 ± 23.0 years; 68.3% male; Injury Severity Score 12.6 ± 11.1), 4.7% died and 8547 (18%) received at least one blood component through HMC. Firearms injuries were the most often transfused (690/2596, 26.6%) and the most urgently (39.9% ≥3 units in <1 h; 40.6% ≥5 units in <4 h), and had the highest mortality (case-fatality, 12.2%) (all p < .001). From-scene patients were younger than transfers (42.9 ± 21.0 vs. 47.2 ± 24.4), predominated among firearms injuries (68.2% from-scene vs. 31.8% transfers), were more likely to receive blood (18.5% vs. 17.6%) more urgently (≥3 units first hour, 24.4% vs. 7.7%; ≥5 units first 4 h: 25.6% vs. 8.2%), were more likely to die of hemorrhage (15.5% vs. 4.3%) and from firearms injuries (310/1360, 22.8%) (all p < .001).

DISCUSSION

Early blood use, firearms injuries, and mortality were all greater among from-scene patients, and firearms injuries had worse outcomes despite greater and more urgent blood use, but the role of survivor bias for transfer patients must be clarified. Future research must identify strategies for providing local hemostatic transfusion support, particularly for firearms injuries.

Ex vivo hemostatic and immuno-inflammatory profiles of freeze-dried plasma

BACKGROUND

Hemorrhage is a leading cause of preventable death in civilian and military trauma. Freeze-dried plasma is promising for hemostatic resuscitation in remote prehospital settings, given its potential benefits in reducing blood loss and mortality, long storage at ambient temperatures, high portability, and rapid reconstitution for transfusion in austere environments. Here we assess the ex vivo characteristics of a novel Terumo's freeze-dried plasma product (TFDP).

STUDY DESIGN AND METHODS

Rotational thromboelastometry (ROTEM) tests (INTEM, EXTEM, and FIBTEM) were conducted on plasma samples at 37°C with a ROTEM delta-machine using standard reagents and procedures. The following samples were analyzed: pooled plasma to produce TFDP, TFDP reconstituted, and stored immediately at -80°C, reconstituted TFDP stored at 4°C for 24 h and room temperature (RT) for 4 h before freezing at -80°C. Analysis of plasma concentrations of selected cytokines, chemokines, and vascular molecules was performed using a multiplex immunoassay system. One-way ANOVA with post hoc tests assessed differences in hemostatic and inflammatory properties.

RESULTS

No significant differences in ROTEM variables (coagulation time [CT], clot formation time, α-angle, maximum clot firmness, and lysis index 30) between the TFDP-producing plasma and reconstituted TFDP samples were observed. Compared to control plasma, reconstituted TFDP stored at 4°C for 24 h or RT for 4 h showed a longer INTEM CT. Levels of immuno-inflammatory mediators were similar between frozen plasma and TFDP.

CONCLUSIONS

TFDP is equivalent to frozen plasma with respect to global hemostatic and immuno-inflammatory mediator profiles. Further investigations of TFDP in trauma-induced coagulopathy models and bleeding patients are warranted.

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.

Recommended primary outcomes for clinical trials evaluating hemostatic blood products and agents in patients with bleeding: Proceedings of a National Heart Lung and Blood Institute and US Department of Defense Consensus Conference

ABSTRACT

High-quality evidence guiding optimal transfusion and other supportive therapies to reduce bleeding is needed to improve outcomes for patients with either severe bleeding or hemostatic disorders that are associated with poor outcomes. Alongside challenges in performing high-quality clinical trials in patient populations who are at risk of bleeding or who are actively bleeding, the interpretation of research evaluating hemostatic agents has been limited by inconsistency in the choice of primary trial outcomes. This lack of standardization of primary endpoints or outcomes decreases the ability of clinicians to assess the validity of endpoints and compare research results across studies, impairs meta-analytic efforts, and, ultimately, delays the translation of research results into clinical practice. To address this challenge, an international panel of experts was convened by the National Heart Lung and Blood Institute and the US Department of Defense on September 23 and 24, 2019, to develop expert opinion, consensus-based recommendations for primary clinical trial outcomes for pivotal trials in pediatric and adult patients with six categories in various clinical settings. This publication documents the conference proceedings from the workshop funded by the National Heart Lung and Blood Institute and the US Department of Defense that consolidated expert opinion regarding clinically meaningful outcomes across a wide range of disciplines to provide guidance for outcomes of future trials of hemostatic products and agents for patients with active bleeding.

Civilian walking blood bank emergency preparedness plan

BACKGROUND

The current global pandemic has created unprecedented challenges in the blood supply network. Given the recent shortages, there must be a civilian plan for massively bleeding patients when there are no blood products on the shelf. Recognizing that the time to death in bleeding patients is less than 2 h, timely resupply from unaffected locations is not possible. One solution is to transfuse emergency untested whole blood (EUWB), similar to the extensive military experience fine-tuned over the last 19 years. While this concept is anathema in current civilian transfusion practice, it seems prudent to have a vetted plan in place.

METHODS AND MATERIALS

During the early stages of the 2020 global pandemic, a multidisciplinary and international group of clinicians with broad experience in transfusion medicine communicated routinely. The result is a planning document that provides both background information and a high-level guide on how to emergently deliver EUWB for patients who would otherwise die of hemorrhage.

RESULTS AND CONCLUSIONS

Similar plans have been utilized in remote locations, both on the battlefield and in civilian practice. The proposed recommendations are designed to provide high-level guidance for experienced blood bankers, transfusion experts, clinicians, and health authorities. Like with all emergency preparedness, it is always better to have a well-thought-out and trained plan in place, rather than trying to develop a hasty plan in the midst of a disaster. We need to prevent the potential for empty shelves and bleeding patients dying for lack of blood.