Improving Survival with Tranexamic Acid in Cerebral Contusions or Traumatic Subarachnoid Hemorrhage: Univariate and Multivariate Analysis of Independent Factors Associated with Lower Mortality

Antifibrinolytics in the treatment of traumatic brain injury

PURPOSE OF REVIEW

Traumatic brain injury (TBI) is a leading cause of trauma-related deaths, and pharmacologic interventions to limit intracranial bleeding should improve outcomes. Tranexamic acid reduces mortality in injured patients with major systemic bleeding, but the effects of antifibrinolytic drugs on outcomes after TBI are less clear. We therefore summarize recent evidence to guide clinicians on when (not) to use antifibrinolytic drugs in TBI patients.

RECENT FINDINGS

Tranexamic acid is the only antifibrinolytic drug that has been studied in patients with TBI. Several recent studies failed to conclusively demonstrate a benefit on survival or neurologic outcome. A large trial with more than 12 000 patients found no significant effect of tranexamic acid on head-injury related death, all-cause mortality or disability across the overall study population, but observed benefit in patients with mild to moderate TBI. Observational evidence signals potential harm in patients with isolated severe TBI.

SUMMARY

Given that the effect of tranexamic acid likely depends on a variety of factors, it is unlikely that a 'one size fits all' approach of administering antifibrinolytics to all patients will be helpful. Tranexamic acid should be strongly considered in patients with mild to moderate TBI and should be avoided in isolated severe TBI.

Construction and Evaluation of Prognosis Prediction Model for Patients with Brain Contusion and Laceration Based on Machine Learning

Objective

Finding valuable risk factors for the prognosis of brain contusion and laceration can help patients understand the condition and improve the prognosis. This study is aimed at analyzing the risk factors of poor prognosis in patients with brain contusion after the operation.

Methods

A total of 136 patients with cerebral contusion and laceration combined with cerebral hernia treated by neurosurgical craniotomy in our hospital were retrospectively selected and divided into a training set (n = 95) and a test set (n = 41) by the 10-fold crossover method. Logistic regression and back-propagation neural network prediction models were established to predict poor prognosis factors. The receiver operating characteristic curve (ROC) and the calibration curve were used to verify the differentiation and consistency of the prediction model.

Results

Based on logistic regression and back-propagation neural network prediction models, GCS score ≤ 8 on admission, blood loss ≥ 30 ml, mannitol ≥ 2 weeks, anticoagulants before admission, and surgical treatment are the risk factors that affect the poor prognosis of patients with a cerebral contusion after the operation. The area under the ROC was 0.816 (95% CI 0.705~0.926) and 0.819 (95% CI 0.708~0.931), respectively.

Conclusion

The prediction model based on the risk factors that affect the poor prognosis of patients with brain contusion and laceration has good discrimination and accuracy.

Association of Tranexamic Acid Administration With Mortality and Thromboembolic Events in Patients With Traumatic Injury: A Systematic Review and Meta-analysis

IMPORTANCE

Tranexamic 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 MEASURES

Outcomes 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.

RESULTS

Thirty-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]; I2 = 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 RELEVANCE

These 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.

Early Tranexamic Acid Administration After Traumatic Brain Injury Is Associated With Reduced Syndecan-1 and Angiopoietin-2 in Patients With Traumatic Intracranial Hemorrhage

OBJECTIVE

To evaluate the effect of early tranexamic acid (TXA) administration on circulating markers of endotheliopathy.

SETTING

Twenty trauma centers in the United States and Canada.

PARTICIPANTS

Patients with moderate-to-severe traumatic brain injury (TBI) (MS-TBI) and intracranial hemorrhage who were not in shock (systolic blood pressure ≥90 mm Hg).

DESIGN

TXA (2 g) or placebo administered prior to hospital arrival, less than 2 hours postinjury. Blood samples and head computed tomographic scan collected upon arrival. Plasma markers measured using Luminex analyte platform. Differences in median marker levels evaluated using t tests performed on log-transformed variables. Comparison groups were TXA versus placebo and less than 45 minutes versus 45 minutes or more from time of injury to treatment administration.

MAIN MEASURES

Plasma levels of angiopoietin-1, angiopoietin-2, syndecan-1, thrombomodulin, thrombospondin-2, intercellular adhesion molecule 1, vascular adhesion molecule 1.

RESULTS

Demographics and Injury Severity Score were similar between the placebo (n = 129) and TXA (n = 158) groups. Levels of syndecan-1 were lower in the TXA group (median [interquartile range or IQR] = 254.6 pg/mL [200.7-322.0] vs 272.4 pg/mL [219.7-373.1], P = .05. Patients who received TXA less than 45 minutes postinjury had significantly lower levels of angiopoietin-2 (median [IQR] = 144.3 pg/mL [94.0-174.3] vs 154.6 pg/mL [110.4-209.8], P = .05). No differences were observed in remaining markers.

CONCLUSIONS

TXA may inhibit early upregulation of syndecan-1 and angiopoietin-2 in patients with MS-TBI, suggesting attenuation of protease-mediated vascular glycocalyx breakdown. The findings of this exploratory analysis should be considered preliminary and require confirmation in future studies.

Tranexamic acid in Neurosurgery: a controversy indication-review

Tranexamic acid (TXA) is one of the measures indicated to reduce bleeding and the need for volume replacement. However, data on risks and benefits are controversial. This study analyzes the effectivity and risks of using tranexamic acid in neurosurgery. We selected articles, published from 1976 to 2019, on the PubMed, EMBASE, Science Direct, and The Cochrane Database using the descriptors: "tranexamic acid," "neurosurgery," "traumatic brain injury," "subdural hemorrhage," "brain aneurysm," and "subarachnoid hemorrhage." TXA can reduce blood loss and the need for blood transfusion in trauma and spinal surgery. Despite the benefits of TXA, moderate-to-high doses are potentially associated with neurological complications (seizures, transient ischemic attack, delirium) in adults and children. In a ruptured intracranial aneurysm, the use of TXA can considerably reduce the risk of rebleeding, but there is weak evidence regarding its influence on mortality reduction. The TXA use in brain surgery does not present benefit. However, this conclusion is limited because there are few studies. TXA in neurosurgeries is a promising method for the maintenance of hemostasis in affected patients, mainly in traumatic brain injury and spinal surgery; nevertheless, there is lack of evidence in brain and vascular surgeries. Many questions remain unanswered, such as how to determine the dosage that triggers the onset of associated complications, or how to adjust the dose for chronic kidney disease patients.

Tranexamic acid is associated with reduced mortality, hemorrhagic expansion, and vascular occlusive events in traumatic brain injury - meta-analysis of randomized controlled trials

Background

This systematic review and meta-analysis aimed to synthesize the latest evidence on the efficacy and safety of tranexamic acid (TXA) on traumatic brain injury (TBI).

Methods

We performed a systematic literature search on topics that compared intravenous TXA to placebo in patients with TBI up until January 2020 from several electronic databases.

Results

There were 30.522 patients from 7 studies. Meta-analysis showed that TXA was associated with reduced mortality (RR 0.92 [0.88, 0.97], p = 0.002; I²: 0%) and hemorrhagic expansion (RR 0.79 [0.64, 0.97], p = 0.03; I²: 0%). Both TXA and control group has a similar need for neurosurgical intervention (p = 0.87) and unfavourable Glasgow Outcome Scale (GOS) (p = 0.59). The rate for vascular occlusive events (p = 0.09), and its deep vein thrombosis subgroup (p = 0.23), pulmonary embolism subgroup (p = 1), stroke subgroup (p = 0.38), and myocardial infarction subgroup (p = 0.15) were similar in both groups. Subgroup analysis on RCTs with low risk of bias showed that TXA was associated with reduced mortality and hemorrhagic expansion. TXA was associated with reduced vascular occlusive events (RR 0.85 [0.73, 0.99], p = 0.04; I²: 4%). GRADE was performed for the RCT with low risk of bias subgroup, it showed a high certainty of evidence for lower mortality, less hemorrhage expansion, and similar need for neurosurgical intervention in TXA group compared to placebo group.

Conclusion

TXA was associated with reduced mortality and hemorrhagic expansion but similar need for neurosurgical intervention and unfavorable GOS. Vascular occlusive events were slightly lower in TXA group on subgroup analysis of RCTs with low risk of bias.