Coagulopathy in patients with traumatic brain injury is associated with an increase in morbidity and mortality. Although timely and aggressive treatment of coagulopathy is of paramount importance, excessive transfusion of blood products has been linked with poor long-term outcomes in patients with traumatic brain injury. A pointof-care thromboelastometric-guided algorithm could assist in creating a more individually tailored approach to each patient. The aim of this study was to evaluate the feasibility of implementing a thromboelastometricguided algorithm in centres that were formerly na€ ıve to thromboelastometry. Hence, we developed such an algorithm and provided training to four centres across Europe to direct the haemostatic management of patients with severe traumatic brain injury. The primary outcome was adherence to the algorithm and timing of the availability of relevant results. Thirty-two patients were included in the study. Complete adherence to the algorithm was observed in 20 out of 32 cases. The availability of thromboelastometric results after hospital admission was reported significantly earlier than conventional coagulation tests (median (IQR [range]) 33 (20-40 [14-250]) min vs. 71 (51-101 [32-290]) min; p = 0.037). Although only 5 out of 32 patients had abnormalities of conventional coagulation tests, 21 out of 32 patients had a coagulopathic baseline thromboelastometric trace. Implementing a thromboelastometric-guided algorithm for the haemostatic therapy of traumatic brain injury is feasible in centres formerly na€ ıve to this technology and may lead to more rapid and precise coagulation management. Further large-scale studies are warranted to confirm the results of this pilot trial and evaluate clinical outcomes.

IMPORTANCETranexamic acid is widely available and used off-label in patients with bleeding traumatic injury, although the literature does not consistently agree on its efficacy and safety. OBJECTIVE To examine the association of tranexamic acid administration with mortality and thromboembolic events compared with no treatment or with placebo in patients with traumatic injury in the literature. DATA SOURCES On March 23, 2021, PubMed, Embase, and the Cochrane Library were searched for eligible studies published between 1986 and 2021. STUDY SELECTION Randomized clinical trials and observational studies investigating tranexamic acid administration compared with no treatment or placebo among patients with traumatic injury and traumatic brain injury who were 15 years or older were included. Included studies were published in English or German. The electronic search yielded 1546 records, of which 71 were considered for full-text screening. The selection process was performed independently by 2 reviewers. DATA EXTRACTION AND SYNTHESIS The study followed the Cochrane Handbook for Systematic Reviews of Interventions and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data were extracted by 2 independent reviewers and pooled using the inverse-variance random-effects model. MAIN OUTCOMES AND MEASURESOutcomes were formulated before data collection and included mortality at 24 hours and 28 and 30 days (1 month) as well as the incidence of thromboembolic events and the amount of blood products administered. Owing to missing data, overall mortality was added and the amount of blood products administered was discarded. RESULTSThirty-one studies with a total of 43 473 patients were included in the systematic review.The meta-analysis demonstrated that administration of tranexamic acid was associated with a significant decrease in 1-month mortality compared with the control cohort (risk ratio, 0.83 [95% CI, 0.71-0.97]; I 2 = 35%). The results of meta-analyses for 24-hour and overall mortality and thromboembolic events were heterogeneous and could not be pooled. Further investigations on clinical heterogeneity showed that populations with trauma and trial conditions differed markedly. CONCLUSIONS AND RELEVANCEThese findings suggest that tranexamic acid may be beneficial in various patient populations with trauma. However, reasonable concerns about potential thromboembolic events with tranexamic acid remain.

Background Trauma-induced coagulopathy in patients with traumatic brain injury (TBI) is associated with high rates of complications, unfavourable outcomes and mortality. The mechanism of the development of TBI-associated coagulopathy is poorly understood. Methods This analysis, embedded in the prospective, multi-centred, observational Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study, aimed to characterise the coagulopathy of TBI. Emphasis was placed on the acute phase following TBI, primary on subgroups of patients with abnormal coagulation profile within 4 h of admission, and the impact of pre-injury anticoagulant and/or antiplatelet therapy. In order to minimise confounding factors, patients with isolated TBI (iTBI) (n = 598) were selected for this analysis. Results Haemostatic disorders were observed in approximately 20% of iTBI patients. In a subgroup analysis, patients with pre-injury anticoagulant and/or antiplatelet therapy had a twice exacerbated coagulation profile as likely as those without premedication. This was in turn associated with increased rates of mortality and unfavourable outcome post-injury. A multivariate analysis of iTBI patients without pre-injury anticoagulant therapy identified several independent risk factors for coagulopathy which were present at hospital admission. Glasgow Coma Scale (GCS) less than or equal to 8, base excess (BE) less than or equal to − 6, hypothermia and hypotension increased risk significantly. Conclusion Consideration of these factors enables early prediction and risk stratification of acute coagulopathy after TBI, thus guiding clinical management.

Fig. 1. Study inclusion and exclusion process. Diagram demonstrating the inclusion and exclusion process for this systematic review. Articles written in languages other than English (non-English), articles involving animal models (nonhuman), and articles not pertaining to the review question (not relevant) were excluded during title/abstract screening. Articles that investigated an exposure other than platelet transfusion (wrong exposure) or an outcome other than mortality (wrong outcome), or studies that used a study design other than randomized controlled trial or cohort study (wrong study design), were excluded during full-text screening.