Early prediction of acute traumatic coagulopathy: a validation of the COAST score using the German Trauma Registry

Development and validation of the tic score for early detection of traumatic coagulopathy upon hospital admission: a cohort study

BACKGROUND

Critically injured patients need rapid and appropriate hemostatic treatment, which requires prompt identification of trauma-induced coagulopathy (TIC) upon hospital admission. We developed and validated the performance of a clinical score based on prehospital resuscitation parameters and vital signs at hospital admission for early diagnosis of TIC.

METHODS

The score was derived from a level-1 trauma center registry (training set). It was then validated on data from two other level-1 trauma centers: first on a trauma registry (retrospective validation set), and then on a prospective cohort (prospective validation set). TIC was defined as a PTratio > 1.2 at hospital admission. Prehospital (vital signs and resuscitation care) and admission data (vital signs and laboratory parameters) were collected. We considered parameters independently associated with TIC in the score (binomial logistic regression). We estimated the score's performance for the prediction of TIC.

RESULTS

A total of 3489 patients were included, and among these a TIC was observed in 22% (95% CI 21-24%) of cases. Five criteria were identified and included in the TIC Score: Glasgow coma scale < 9, Shock Index > 0.9, hemoglobin < 11 g.dL-1, prehospital fluid volume > 1000 ml, and prehospital use of norepinephrine (yes/no). The score, ranging from 0 and 9 points, had good performance for the identification of TIC (AUC: 0.82, 95% CI: 0.81-0.84) without differences between the three sets used. A score value < 2 had a negative predictive value of 93% and was selected to rule-out TIC. Conversely, a score value ≥ 6 had a positive predictive value of 92% and was selected to indicate TIC.

CONCLUSION

The TIC Score is quick and easy to calculate and can accurately identify patients with TIC upon hospital admission.

A Systematic Review of Tranexamic Acid-Associated Venous Thromboembolic Events in Combat Casualties and Considerations for Prolonged Field Care

INTRODUCTION

Tranexamic acid (TXA) is a standard component of Tactical Combat Casualty Care. Recent retrospective studies have shown that TXA use is associated with a higher rate of venous thromboembolic (VTE) events in combat-injured patients. We aim to determine if selective administration should be considered in the prolonged field care environment.

MATERIALS AND METHODS

We performed a systematic review using the 2020 Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Clinical trials and observational studies of combat casualties published between January 1, 1960, and June 20, 2022, were included. We analyzed survival and VTE outcomes in TXA recipients and non-recipients. We discussed the findings of each paper in the context of current and future combat environments.

RESULTS

Six articles met criteria for inclusion. Only one study was powered to report mortality data, and it demonstrated a 7-fold increase in survival in severely injured TXA recipients. All studies reported an increased risk of VTE in TXA recipients, which exceeded rates in civilian literature. However, five of the six studies used overlapping data from the same registry and were limited by a high rate of missingness in pertinent variables. No VTE-related deaths were identified.

CONCLUSIONS

There may be an increased risk of VTE in combat casualties that receive TXA; however, this risk must be considered in the context of improved survival and an absence of VTE-associated deaths. To optimize combat casualty care during prolonged field care, it will be essential to ensure the timely administration of VTE chemoprophylaxis as soon as the risk of significant hemorrhage permits.

Prehospital Tranexamic Acid for Severe Trauma

BACKGROUND

Whether prehospital administration of tranexamic acid increases the likelihood of survival with a favorable functional outcome among patients with major trauma and suspected trauma-induced coagulopathy who are being treated in advanced trauma systems is uncertain.

METHODS

We randomly assigned adults with major trauma who were at risk for trauma-induced coagulopathy to receive tranexamic acid (administered intravenously as a bolus dose of 1 g before hospital admission, followed by a 1-g infusion over a period of 8 hours after arrival at the hospital) or matched placebo. The primary outcome was survival with a favorable functional outcome at 6 months after injury, as assessed with the use of the Glasgow Outcome Scale-Extended (GOS-E). Levels on the GOS-E range from 1 (death) to 8 ("upper good recovery" [no injury-related problems]). We defined survival with a favorable functional outcome as a GOS-E level of 5 ("lower moderate disability") or higher. Secondary outcomes included death from any cause within 28 days and within 6 months after injury.

RESULTS

A total of 1310 patients were recruited by 15 emergency medical services in Australia, New Zealand, and Germany. Of these patients, 661 were assigned to receive tranexamic acid, and 646 were assigned to receive placebo; the trial-group assignment was unknown for 3 patients. Survival with a favorable functional outcome at 6 months occurred in 307 of 572 patients (53.7%) in the tranexamic acid group and in 299 of 559 (53.5%) in the placebo group (risk ratio, 1.00; 95% confidence interval [CI], 0.90 to 1.12; P = 0.95). At 28 days after injury, 113 of 653 patients (17.3%) in the tranexamic acid group and 139 of 637 (21.8%) in the placebo group had died (risk ratio, 0.79; 95% CI, 0.63 to 0.99). By 6 months, 123 of 648 patients (19.0%) in the tranexamic acid group and 144 of 629 (22.9%) in the placebo group had died (risk ratio, 0.83; 95% CI, 0.67 to 1.03). The number of serious adverse events, including vascular occlusive events, did not differ meaningfully between the groups.

CONCLUSIONS

Among adults with major trauma and suspected trauma-induced coagulopathy who were being treated in advanced trauma systems, prehospital administration of tranexamic acid followed by an infusion over 8 hours did not result in a greater number of patients surviving with a favorable functional outcome at 6 months than placebo. (Funded by the Australian National Health and Medical Research Council and others; PATCH-Trauma ClinicalTrials.gov number, NCT02187120.).

Trauma-induced disturbances in ionized calcium levels correlate parabolically with coagulopathy, transfusion, and mortality: a multicentre cohort analysis from the TraumaRegister DGU®

BACKGROUND

To which extent trauma- induced disturbances in ionized calcium (iCa2+) levels have a linear relationship with adverse outcomes remains controversial. The goal of this study was to determine the association between the distribution and accompanying characteristics of transfusion-independent iCa2+ levels versus outcome in a large cohort of major trauma patients upon arrival at the emergency department.

METHODS

A retrospective observational analysis of the TraumaRegister DGU® (2015-2019) was performed. Adult major trauma patients with direct admission to a European trauma centre were selected as the study cohort. Mortality at 6 h and 24 h, in-hospital mortality, coagulopathy, and need for transfusion were considered as relevant outcome parameters. The distribution of iCa2+ levels upon arrival at the emergency department was calculated in relation to these outcome parameters. Multivariable logistic regression analysis was performed to determine independent associations.

RESULTS

In the TraumaRegister DGU® 30 183 adult major trauma patients were found eligible for inclusion. iCa2+ disturbances affected 16.4% of patients, with hypocalcemia (< 1.10 mmol/l) being more frequent (13.2%) compared to hypercalcemia (≥ 1.30 mmol/l, 3.2%). Patients with hypo- and hypercalcemia were both more likely (P < .001) to have severe injury, shock, acidosis, coagulopathy, transfusion requirement, and haemorrhage as cause of death. Moreover, both groups had significant lower survival rates. All these findings were most distinct in hypercalcemic patients. When adjusting for potential confounders, mortality at 6 h was independently associated with iCa2+ < 0.90 mmol/L (OR 2.69, 95% CI 1.67-4.34; P < .001), iCa2+ 1.30-1.39 mmol/L (OR 1.56, 95% CI 1.04-2.32, P = 0.030), and iCa2+  ≥ 1.40 mmol/L (OR 2.87, 95% CI 1.57-5.26; P < .001). Moreover, an independent relationship was determined for iCa2+ 1.00-1.09 mmol/L with mortality at 24 h (OR 1.25, 95% CI 1.05-1.48; P = .0011), and with in-hospital mortality (OR 1.29, 95% CI 1.13-1.47; P < .001). Both hypocalcemia < 1.10 mmol/L and hypercalcemia ≥ 1.30 mmol/L had an independent association with coagulopathy and transfusion.

CONCLUSIONS

Transfusion-independent iCa2+ levels in major trauma patients upon arrival at the emergency department have a parabolic relationship with coagulopathy, need for transfusion, and mortality. Further research is needed to confirm whether iCa2+ levels change dynamically and are more a reflection of severity of injury and accompanying physiological derangements, rather than an individual parameter that needs to be corrected as such.

Predictors of transfusion in trauma and their utility in the prehospital environment: a scoping review

Background: Hemorrhage is a leading cause of preventable mortality from trauma, necessitating resuscitation through blood product transfusions. Early and accurate identification of patients requiring transfusions in the prehospital setting may reduce delays in time to transfusion upon arrival to hospital, reducing mortality. The purpose of this study is to characterize existing literature on predictors of transfusion and analyze their utility in the prehospital context.Objectives: The objectives of this study are to characterize the existing quantity and quality of literature regarding predictor scores for transfusion in injured patients, and to analyse the utility of predictor scores for massive transfusions in the prehospital setting and identify prehospital predictor scores for future research.Methods: A search strategy was developed in consultation with information specialists. A literature search of OVID MEDLINE from 1946 to present was conducted for primary studies evaluating the predictive ability of scoring systems or single variables in predicting transfusion in all trauma settings.Results: Of the 5824 studies were identified, 5784 studies underwent title and abstract screening, 94 studies underwent full text review, and 72 studies were included in the final review. We identified 16 single variables and 52 scoring systems for predicting transfusion. Amongst single predictor variables, fluids administered and systolic blood pressure had the highest reported sensitivity (100%) and specificity (89%) for massive transfusion protocol (MTP) activation respectively. Amongst scoring systems for transfusion, the Shock Index and Modified Shock Index had the highest reported sensitivity (96%), while the Pre-arrival Model had the highest reported specificity (95%) for MTP activation. Overall, 20 scores were identified as being applicable to the prehospital setting, 25 scores were identified as being potentially applicable, and seven scores were identified as being not applicable.Conclusions: We identified an extensive list of predictive single variables, validated scoring systems, and derived models for massive transfusion, presented their properties, and identified those with potential utility in the prehospital setting. By further validating applicable scoring tools in the prehospital setting, we may begin to administer more timely transfusions in the trauma population.

Viscoelastic Testing and Coagulopathy of Traumatic Brain Injury

A unique coagulopathy often manifests following traumatic brain injury, leading the clinician down a difficult decision path on appropriate prophylaxis and therapy. Conventional coagulation assays—such as prothrombin time, partial thromboplastin time, and international normalized ratio—have historically been utilized to assess hemostasis and guide treatment following traumatic brain injury. However, these plasma-based assays alone often lack the sensitivity to diagnose and adequately treat coagulopathy associated with traumatic brain injury. Here, we review the whole blood coagulation assays termed viscoelastic tests and their use in traumatic brain injury. Modified viscoelastic tests with platelet function assays have helped elucidate the underlying pathophysiology and guide clinical decisions in a goal-directed fashion. Platelet dysfunction appears to underlie most coagulopathies in this patient population, particularly at the adenosine diphosphate and/or arachidonic acid receptors. Future research will focus not only on the utility of viscoelastic tests in diagnosing coagulopathy in traumatic brain injury, but also on better defining the use of these tests as evidence-based and/or precision-based tools to improve patient outcomes.

The impact of prehospital tranexamic acid on mortality and transfusion requirements: match-pair analysis from the nationwide German TraumaRegister DGU®

Background

Outcome data about the use of tranexamic acid (TXA) in civilian patients in mature trauma systems are scarce. The aim of this study was to determine how severely injured patients are affected by the widespread prehospital use of TXA in Germany.

Methods

The international TraumaRegister DGU® was retrospectively analyzed for severely injured patients with risk of bleeding (2015 until 2019) treated with at least one dose of TXA in the prehospital phase (TXA group). These were matched with patients who had not received prehospital TXA (control group), applying propensity score-based matching. Adult patients (≥ 16) admitted to a trauma center in Germany with an Injury Severity Score (ISS) ≥ 9 points were included.

Results

The matching yielded two comparable cohorts (n = 2275 in each group), and the mean ISS was 32.4 ± 14.7 in TXA group vs. 32.0 ± 14.5 in control group (p = 0.378). Around a third in both groups received one dose of TXA after hospital admission. TXA patients were significantly more transfused (p = 0.022), but needed significantly less packed red blood cells (p ≤ 0.001) and fresh frozen plasma (p = 0.023), when transfused. Massive transfusion rate was significantly lower in the TXA group (5.5% versus 7.2%, p = 0.015). Mortality was similar except for early mortality after 6 h (p = 0.004) and 12 h (p = 0.045). Among non-survivors hemorrhage as leading cause of death was less in the TXA group (3.0% vs. 4.3%, p = 0.021). Thromboembolic events were not significantly different between both groups (TXA 6.1%, control 4.9%, p = 0.080).

Conclusion

This is the largest civilian study in which the effect of prehospital TXA use in a mature trauma system has been examined. TXA use in severely injured patients was associated with a significantly lower risk of massive transfusion and lower mortality in the early in-hospital treatment period. Due to repetitive administration, a dose-dependent effect of TXA must be discussed.

Trauma-induced coagulopathy

Uncontrolled haemorrhage is a major preventable cause of death in patients with traumatic injury. Trauma-induced coagulopathy (TIC) describes abnormal coagulation processes that are attributable to trauma. In the early hours of TIC development, hypocoagulability is typically present, resulting in bleeding, whereas later TIC is characterized by a hypercoagulable state associated with venous thromboembolism and multiple organ failure. Several pathophysiological mechanisms underlie TIC; tissue injury and shock synergistically provoke endothelial, immune system, platelet and clotting activation, which are accentuated by the 'lethal triad' (coagulopathy, hypothermia and acidosis). Traumatic brain injury also has a distinct role in TIC. Haemostatic abnormalities include fibrinogen depletion, inadequate thrombin generation, impaired platelet function and dysregulated fibrinolysis. Laboratory diagnosis is based on coagulation abnormalities detected by conventional or viscoelastic haemostatic assays; however, it does not always match the clinical condition. Management priorities are stopping blood loss and reversing shock by restoring circulating blood volume, to prevent or reduce the risk of worsening TIC. Various blood products can be used in resuscitation; however, there is no international agreement on the optimal composition of transfusion components. Tranexamic acid is used in pre-hospital settings selectively in the USA and more widely in Europe and other locations. Survivors of TIC experience high rates of morbidity, which affects short-term and long-term quality of life and functional outcome.

Protocol for a multicentre prehospital randomised controlled trial investigating tranexamic acid in severe trauma: the PATCH-Trauma trial

INTRODUCTION

Haemorrhage causes most preventable prehospital trauma deaths and about a third of in-hospital trauma deaths. Tranexamic acid (TXA), administered soon after hospital arrival in certain trauma systems, is an effective therapy in preventing or managing acute traumatic coagulopathy. However, delayed administration of TXA appears to be ineffective or harmful. The effectiveness of prehospital TXA, incidence of thrombotic complications, benefit versus risk in advanced trauma systems and the mechanism of benefit remain uncertain.

METHODS AND ANALYSIS

The Pre-hospital Anti-fibrinolytics for Traumatic Coagulopathy and Haemorrhage (The PATCH-Trauma study) is comparing TXA, initiated prehospital and continued in hospital over 8 hours, with placebo in patients with severe trauma at risk of acute traumatic coagulopathy. We present the trial protocol and an overview of the statistical analysis plan. There will be 1316 patients recruited by prehospital clinicians in Australia, New Zealand and Germany. The primary outcome will be the eight-level Glasgow Outcome Scale Extended (GOSE) at 6 months after injury, dichotomised to favourable (GOSE 5-8) and unfavourable (GOSE 1-4) outcomes, analysed using an intention-to-treat (ITT) approach. Secondary outcomes will include mortality at hospital discharge and at 6 months, blood product usage, quality of life and the incidence of predefined adverse events.

ETHICS AND DISSEMINATION

The study was approved by The Alfred Hospital Research and Ethics Committee in Victoria and also approved in New South Wales, Queensland, South Australia, Tasmania and the Northern Territory. In New Zealand, Northern A Health and Disability Ethics Committee provided approval. In Germany, Witten/Herdecke University has provided ethics approval. The PATCH-Trauma study aims to provide definitive evidence of the effectiveness of prehospital TXA, when used in conjunction with current advanced trauma care, in improving outcomes after severe injury.

TRIAL REGISTRATION NUMBER

NCT02187120.