Time Course of Coagulation and Fibrinolytic Parameters in Patients with Traumatic Brain Injury

Treatment strategies for patients with out-of-hospital cardiac arrest associated with traumatic brain injury: A case series

INTRODUCTION

Collapse after out-of-hospital cardiac arrest (OHCA) can cause severe traumatic brain injury (TBI). We aimed to investigate the clinical characteristics and treatment strategies for patients with OHCA and TBI.

METHODS

We analyzed a consecutive cohort of patients with intrinsic OHCA retrospectively treated between January 2011 and December 2021 at a single critical care center, and presented a case series of seven patients. Patients with collapse-related TBI were examined for the causes and situations of cardiac arrest, laboratory data, radiological images, targeted temperature management (TTM), coronary angiography (CAG), percutaneous coronary intervention (PCI), and extracorporeal cardiopulmonary resuscitation (ECPR).

RESULTS

Of the 197 patients with intrinsic OHCA, 7 (3.6%) had TBI (age range: 49-70 years; 6 men). All seven patients presented with ventricular fibrillation in the initial electrocardiograms, with four refractory cases treated with ECPR. All patients underwent CAG under heparinization, and four underwent PCI with antiplatelet administration. Initial head computed tomography indicated an intracranial hemorrhage (ICH) in three patients. ICH appeared or was exacerbated in six patients after CAG with or without PCI, except in one who underwent delayed PCI. All patients displayed elevated plasma D-dimer levels, and four underwent neurosurgical procedures. Four patients survived (three with cerebral performance category [CPC] 2, one with CPC 3) and three died; two had hypoxic-ischemic brain injury and one had severe TBI.

CONCLUSION

Delayed ICH occurred frequently. Individualized management is required based on the extent of brain and cardiac damage, including optimal TTM, PCI procedures, and antiplatelet medications. Early detection of ICH and emergency treatment are critical for multi-disciplinary collaboration.

Efficacy and safety of tranexamic acid in acute traumatic brain injury: A meta-analysis of randomized controlled trials

INTRODUCTION

Tranexamic acid (TXA) holds a pivotal role in the therapeutic approach to traumatic conditions. Nevertheless, its precise influence on diminishing mortality and limiting the progression of intracranial hemorrhage (ICH) during the treatment of traumatic brain injury (TBI) remains indeterminate.

METHODS

PubMed, EMBASE, Cochrane Library, and Web of Science were searched for randomized controlled trials that compared TXA and a placebo in adults with TBI up to September 31, 2023. Two authors independently abstracted the data and assessed the quality of evidence. Additionally, subgroup analyses were performed to assess outcomes with low heterogenety.

RESULTS

Our search strategy yielded 11,299 patients from 11 studies. The result showed that TXA had no effect on mortality (RR 0.93 [0.86, 1.00], p = 0.06; I2: 0%, p = 0.79), poor clinical outcomes (RR 0.92 [0.78, 1.09], p = 0.34; I2: 0%, p = 0.40), adverse events (RR 0.94 [0.83, 1.07], p = 0.34; I2: 48%, p = 0.10), vascular occlusive events (RR 0.85 [0.68, 1.06], p = 0.16; I2: 32%, p = 0.22), pulmonary embolism (RR 0.76 [0.47, 1.22], p = 0.26; I2: 0%, p = 0.83), seizure (RR 1.11 [0.92, 1.35], p = 0.27; I2: 0%, p = 0.49) and hemorrhagic complications (RR 0.78 [0.55, 1.09], p = 0.14; I2: 0%, p = 0.42). TXA might reduce the rate of hemorrhagic expansion (RR 0.83 [0.70, 0.99], p = 0.03; I2: 18%, p = 0.29) and mean hemorrhage volume (SMD -0.39 [-0.60, -0.18], p <0.001; I2: 44%, p = 0.13).When the time interval from symptom onset to treatment was <3 h, TXA reduced mean hemorrhage volume (SMD -0.51 [-0.81, -0.20], p = 0.001; I2: 0%, p = 0.94).

CONCLUSIONS

TXA did not elevate the risk of adverse event, however, the lack of reduction in mortality and the poor clinical outcomes constrain the value of clinical application. Early administration of TXA (within 3 h) may significantly decrease the likelihood of ICH growth in patients with TBI.

Plasma D-Dimer Levels Can Provide Useful Diagnostic Information on Acute Vertebral Compression Fractures in Patients with Low Back Pain in the Emergency Room

BACKGROUND

Patients with acute vertebral compression fractures (aVCFs) are frequently transferred to an emergency department by ambulance. The most useful imaging modality is magnetic resonance imaging (MRI); however, which patients should be prioritized for MRI evaluation may be unclear. The aim of this study was to evaluate plasma D-dimer levels as a biomarker for aVCFs.

METHODS

This retrospective cohort study included patients with low back pain in the emergency department between November 2017 and October 2020. Patients with infections, patients with coagulation disorders, and patients without D-dimer level measurements were excluded. The presence of an aVCF was detected with MRI. Blood samples were collected for routine blood tests. The predictive factors for aVCFs were evaluated with univariate and multivariable logistic regression analyses.

RESULTS

Overall, 191 consecutive MRI evaluations were ordered. After exclusions, 101 patients were reviewed. Based on MRI, 65 (64.4%) patients were diagnosed with aVCF. The presence of aVCF was significantly correlated with age (odds ratio [OR] = 1.052, 95% confidence interval [CI] 1.018-1.191), an old vertebral compression fracture (OR = 3.290, 95% CI 1.342-8.075), hemoglobin (OR = 0.699, 95% CI 0.535-0.912), and D-dimer levels (OR = 1.829, 95% CI 1.260-2.656). Results from a multivariable logistic regression analysis showed that D-dimer levels (OR = 1.642, 95% CI 1.188-2.228) remained a significant risk factor for the presence of aVCFs after adjustment for potential confounders.

CONCLUSIONS

Plasma D-dimer levels can provide useful diagnostic information about whether an aVCF is present.

Establishment of a model to predict mortality after decompression craniotomy for traumatic brain injury

BACKGROUND

The mortality rate of patients with traumatic brain injury (TBI) is still high even while undergoing decompressive craniectomy (DC), and the expensive treatment costs bring huge economic burden to the families of patients.

OBJECTIVE

The aim of this study was to identify preoperative indicators that influence patient outcomes and to develop a risk model for predicting patient mortality by a retrospective analysis of TBI patients undergoing DC.

METHODS

A total of 288 TBI patients treated with DC, admitted to the First Affiliated Hospital of Shantou University Medical School from August 2015 to April 2021, were used for univariate and multivariate logistic regression analysis to determine the risk factors for death after DC in TBI patients. We also built a risk model for the identified risk factors and conducted internal verification and model evaluation.

RESULTS

Univariate and multivariate logistic regression analysis identified four risk factors: Glasgow Coma Scale, age, activated partial thrombin time, and mean CT value of the superior sagittal sinus. These risk factors can be obtained before DC. In addition, we also developed a 3-month mortality risk model and conducted a bootstrap 1000 resampling internal validation, with C-indices of 0.852 and 0.845, respectively.

CONCLUSIONS

We developed a risk model that has clinical significance for the early identification of patients who will still die after DC. Interestingly, we also identified a new early risk factor for TBI patients after DC, that is, preoperative mean CT value of the superior sagittal sinus (p < .05).

Derivation of Coagulation Phenotypes and the Association with Prognosis in Traumatic Brain Injury: A Cluster Analysis of Nationwide Multicenter Study

BACKGROUND

The pathogenesis and pathophysiology of traumatic coagulopathy during traumatic brain injury is not well understood, and the appropriate treatment strategy for this condition has not been established. This study aimed to evaluate the coagulation phenotypes and their effect on prognosis in patients with isolated traumatic brain injury.

METHODS

In this multicenter cohort study, we retrospectively analyzed data from the Japan Neurotrauma Data Bank. Adults with isolated traumatic brain injury (head abbreviated injury scale > 2; abbreviated injury scale of any other trauma < 3) who were registered in the Japan Neurotrauma Data Bank were included in this study. The primary outcome was the association of coagulation phenotypes with in-hospital mortality. Coagulation phenotypes were derived using k-means clustering with coagulation markers, including prothrombin time international normalized ratio (PT-INR), activated partial thromboplastin time (APTT), fibrinogen (FBG), and D-dimer (DD) on arrival at the hospital. Multivariable logistic regression analyses were conducted to calculate the adjusted odds ratios of coagulation phenotypes with their 95% confidence intervals (CIs) for in-hospital mortality.

RESULTS

In total, 556 patients were enrolled and five coagulation phenotypes were identified. The median (interquartile range) score for the Glasgow Coma Scale was 6 (4-9). Cluster A (n = 129) had the closest to normal coagulation values; cluster B (n = 323) had a mild high DD phenotype; cluster C (n = 30) had a prolonged PT-INR phenotype with a higher frequency of antithrombotic medication in elderly patients than in younger patients; cluster D (n = 45) had a low amount of FBG, high DD, and prolonged APTT phenotype with a high incidence of skull fracture; and cluster E (n = 29) had a low amount of FBG and extremely high DD phenotype with high energy trauma and a high incidence of skull fracture. In the multivariable logistic regression analysis, the association of clusters B, C, D, and E with in-hospital mortality yielded the corresponding adjusted odds ratios of 2.17 (95% CI 1.22-3.86), 2.61 (95% CI 1.01-6.72), 10.0 (95% CI 4.00-25.2), and 24.1 (95% CI 7.12-81.3), respectively, relative to cluster A.

CONCLUSIONS

This multicenter, observational study identified five different coagulation phenotypes of traumatic brain injury and showed associations of these phenotypes with in-hospital mortality.

Effectiveness of Administration of Fibrinogen Concentrate as Prevention of Hypofibrinogenemia in Patients with Traumatic Brain Injury with a Higher Risk for Severe Hyperfibrinolysis: Single Center Before-and-After Study

BACKGROUND

Coagulopathy is often observed in severe traumatic brain injury (sTBI), and hyperfibrinolysis (HF) is associated with a poor prognosis. Although the efficacy of fibrinogen concentrate (FC) in multiple trauma has been reported, its efficacy in sTBI is unclear. Therefore, we delineated severe HF risk factors despite fresh frozen plasma transfusion. Using these risk factors, we defined high-risk patients and determined whether FC administration to this group improved fibrinogen level.

METHODS

In the first part of this study, successive adults with sTBI treated at our hospital between April 2016 and March 2019 were reviewed. Patients underwent transfusion as per our conventional protocol and were divided into two groups based on whether fibrinogen levels of ≥ 150 mg/dL were maintained 3-6 h after arrival to delineate the risk factors of severe HF. In the second part of the study, we conducted a before-and-after study in patients with sTBI who were at a higher risk for severe HF (presence of at least one of the risk factors identified in the first part of the study), comparing those treated with FC between April 2019 and March 2021 (FC group) with those treated with conventional transfusion before FC between April 2016 and March 2019. The primary outcome was maintenance of fibrinogen levels, and the secondary outcome was 30-day mortality.

RESULTS

In the first part of the study, 78 patients were included. Twenty-three patients did not maintain fibrinogen levels ≥ 150 mg/dL. A D-dimer level on arrival > 50 μg/mL, a fibrinogen level on arrival < 200 mg/dL, depressed skull fracture, and multiple trauma were severe HF risk factors. In the second part, compared with 46 patients who were identified as being at high risk for severe HF but were not administered FC (non-FC group), fibrinogen levels ≥ 150 mg/dL 3-6 h after arrival were maintained in 14 of 15 patients in the FC group (odds ratio: 0.07; 95% confidence interval: 0.01-0.59). Although there were significant differences in fibrinogen levels, no significant differences were observed in terms of 30-day mortality between the groups.

CONCLUSIONS

Coagulation abnormalities on arrival, severe skull fracture, and multiple trauma are severe HF risk factors. FC administration may contribute to rapid correction of developing hypofibrinogenemia.

Neutrophil extracellular traps contribute to coagulopathy after traumatic brain injury

Coagulopathy contributes to the majority of deaths and disabilities associated with traumatic brain injury (TBI). Whether neutrophil extracellular traps (NETs) contribute to an abnormal coagulation state in the acute phase of TBI remains unknown. Our objectives were to demonstrate the definitive role of NETs in coagulopathy in TBI. We detected NET markers in 128 TBI patients and 34 healthy individuals. Neutrophil-platelet aggregates were detected in blood samples from TBI patients and healthy individuals using flow cytometry and staining for CD41 and CD66b. Endothelial cells were incubated with isolated NETs and we detected the expression of vascular endothelial cadherin, syndecan-1, thrombomodulin, von Willebrand factor, phosphatidylserine, and tissue factor. In addition, we established a TBI mouse model to determine the potential role of NETs in TBI-associated coagulopathy. NET generation was mediated by high mobility group box 1 (HMGB1) from activated platelets and contributed to procoagulant activity in TBI. Furthermore, coculture experiments indicated that NETs damaged the endothelial barrier and caused these cells to assume a procoagulant phenotype. Moreover, the administration of DNase I before or after brain trauma markedly reduced coagulopathy and improved the survival and clinical outcome of mice with TBI.

Gender-related differences in the coagulofibrinolytic responses and long-term outcomes in patients with isolated traumatic brain injury: A 2-center retrospective study

Coagulation function differs by gender, with women being characterized as more hypercoagulable. Even in the early stages of trauma, women have been shown to be hypercoagulable. Several studies have also examined the relationship between gender and the prognosis of trauma patients, but no certain conclusions have been reached. Patients with isolated traumatic brain injury (iTBI) are known to have coagulopathy, but no previous studies have examined the gender differences in detail. This is a retrospective analysis of a prospective registry conducted at 2 centers. The study included adult patients with iTBI enrolled from April 2018 to March 2021. Coagulofibrinolytic markers were measured in each patient at 1 hour, 24 hours, 3 days, and 7 days after injury, and neurological outcomes were assessed with the Glasgow Outcome Scale Extended at 6 months. Subgroup analysis was also performed by categorizing patients into groups according to neurological prognosis or age at 50 years. Males (n = 31) and females (n = 21) were included in the analysis. In males, there was a significant difference in the levels of activated partial thromboplastin time (P = .007), fibrin/fibrinogen degradation products (P = .025), D-dimer (P = .034), α2-plasmin inhibitor (P = .030), plasmin-α2-plasmin inhibitor complex (P = .004) at 1 hour after injury between favorable and unfavorable long-term neurological outcome groups, while in females there was no significant difference in these markers between 2 groups. In the age group under 50 years, there were significant gender differences in fibrinogen (day 3: P = .018), fibrin/fibrinogen degradation products (1 hour: P = .037, day 3: P = .009, day 7: P = .037), D-dimer (day 3: P = .005, day 7: P = .010), plasminogen (day 3: P = .032, day 7: P = .032), and plasmin-α2-plasmin inhibitor complex (day 3: P = .001, day 7: P = .001), and these differences were not evident in the age group over 50 years. There were differences in coagulofibrinolytic markers depending on gender in patients with iTBI. In male patients, aggravation of coagulofibrinolytic markers immediately after traumatic brain injury may be associated with poor neurologic outcome 6 months after injury.

Optic nerve sheath diameter as a quantitative parameter associated with the outcome in patients with traumatic brain injury undergoing hematoma removal

PURPOSE

To determine the association between optic nerve sheath diameter (ONSD) and outcome in patients with traumatic brain injury (TBI) who undergo hematoma removal (HR).

METHODS

This study was a retrospective analysis of data from a single center between 2016 and 2021. Adult patients with TBI who underwent HR within 24 h after admission were included in this study. Preoperative and postoperative ONSD of the surgical side and the mean ONSD of both sides were measured for analysis. The primary outcome was mortality at 30 days. Receiver operating characteristic curve analysis was performed to calculate the area under the curve (AUC) and 95% confidence interval (CI) for 30 days mortality.

RESULTS

Sixty-one patients were enrolled in the study. Among them, 48 (78.7%) survived for 30 days after admission. The AUC and 95% CI of the postoperative mean ONSD on both sides and postoperative/preoperative mean of the ONSD ratio on both sides were 0.884 [0.734-0.955] and 0.875 [0.751-0.942], respectively. The postoperative mean of both ONSDs of 6.0 mm had high accuracy as a cut-off value with a sensitivity of 85%, specificity of 83%, positive likelihood ratio (LR) of 5.0, and negative LR- of 0.18.

CONCLUSION

This study demonstrated that postoperative ONSD and the postoperative/preoperative ONSD ratio were associated with postoperative outcome in patients with TBI who underwent HR.

Emergent surgical evacuation of traumatic intracranial hematoma in patients with preoperative thrombocytopenia: surgical risk and early outcome

BACKGROUND

Surgical evacuation of intracranial hematoma, including epidural, subdural, intracerebral, and intraventricular hematoma, is recommended in patients with traumatic brain injury (TBI) for prevention of cerebral herniation and possible saving of life. However, preoperative coagulopathy is a major concern for emergent surgery on patients with severe TBI.

METHODS

We reviewed 65 consecutive patients with severe TBI who underwent emergency craniotomy for intracranial hematomas.

RESULTS

Univariate analysis showed preoperative pupil abnormality, absence of pupil light reflex, respiratory failure, preoperative thrombocytopenia (< 100 × 10⁹/L), increased activated partial thromboplastin time (> 36 s), low fibrinogen (< 150 mg/dL), platelet transfusion, red cell concentrate transfusion, and presence of brain contusion and traumatic subarachnoid hemorrhage (SAH) on computed tomography were correlated with poor outcome (death or vegetative state). Multivariate analysis revealed that pupil abnormality (p = 0.001; odds ratio [OR] 0.064, 95% confidence interval [CI] 0.012-0.344), preoperative thrombocytopenia (p = 0.016; OR 0.101, 95% CI 0.016-0.656), and traumatic SAH (p = 0.021; OR 0.211, 95% CI 0.057-0.791) were significant factors. Investigation of the 14 patients with preoperative thrombocytopenia found the emergency surgery was successful, with no postoperative bleeding during hospitalization. However, half of the patients died, and almost a quarter remained in the vegetative state mainly associated with severe cerebral edema.

CONCLUSIONS

Emergent craniotomy for patients with severe TBI who have preoperative thrombocytopenia is often successful, but the prognosis is often poor. Emergency medical care teams and neurosurgeons should be aware of this discrepancy between successful surgery and poor prognosis in these patients. Further study may be needed on the cerebral edema regulator function of platelets.

Longitudinal D-Dimer Trajectories and the Risk of Mortality in Abdominal Trauma Patients: A Group-Based Trajectory Modeling Analysis

This study aimed to identify the long-term D-dimer trajectory patterns and their associations with in-hospital all-cause mortality in abdominal trauma patients. This is a retrospective cohort study of general adult abdominal trauma patients admitted to Jinling Hospital (Nanjing, China) between January 2010 and April 2020. Group-based trajectory modeling was applied to model D-dimer trajectories over the first 50 days post-trauma. A multivariable logistic regression was performed to estimate the associations between D-dimer trajectories and in-hospital all-cause mortality. A total of 309 patients were included. We identified four distinct D-dimer trajectories: group 1 (57.61%; "stable low"), group 2 (28.16%; "moderate-decline"), group 3 (8.41%; "high-rapid decline"), and group 4 (5.83%; "high-gradual decline"). The SOFA score (p = 0.005) and ISS (p = 0.001) were statistically higher in groups 3 and 4 than in groups 1 and 2. The LMWH and UFH did not differ between groups 3 and 4. Compared with the patients in group 1, only the patients in group 4 were at a higher risk of in-hospital all-cause mortality (OR = 6.94, 95% CI: 1.20-40.25). The long-term D-dimer trajectories post-trauma were heterogeneous and associated with mortality. An initially high and slowly-resolved D-dimer might function as the marker of disease deterioration, and specific interventions are needed.

Acute epidural vertex hematoma with good hemostasis using delayed surgery after monitoring of coagulation and fibrinolytic parameters: A case report

Background

The appropriate timing and method of surgery for vertex epidural hematoma (VEDH) are uncertain due to the presentation and slow symptomatic exacerbation caused by bleeding from a venous origin involving the injured superior sagittal sinus (SSS). Coagulation and fibrinolytic disorders that occur after traumatic brain injury also worsen bleeding. For these reasons, it is challenging to decide the surgical procedure and timing of surgery.

Case Description

A 24-year-old man involved a car accident and was transported to our emergency department. He was unconscious but not lethargic. Computed tomography showed VEDH overlying the SSS, and hematoma increased temporarily. Due to abnormal coagulation and fibrinolysis at admission, he underwent intentionally delayed surgery after control of coagulation and fibrinolysis. Bilateral parasagittal craniotomy was chosen to ensure hemostasis from the torn SSS. The patient improved without complications and was discharged with no neurological deficit. This case indicates that this surgical strategy is favorable for VEDH with slow symptomatic progression.

Conclusion

VEDH is mostly caused by bleeding from the injured SSS secondary to diastatic fracture of sagittal suture. Intentionally delayed surgical intervention using bilateral parasagittal craniotomy after stabilization of coagulation and fibrinolysis is favorable for prevention of further hemorrhage and good hemostasis.

Association of Extravascular Leakage on Computed Tomography Angiography with Fibrinogen Levels at Admission in Patients with Traumatic Brain Injury

Extravascular leakage on computed tomography (CT) angiography in patients with traumatic brain injury (TBI) is associated with hematoma expansion, functional prognosis, subsequent surgery, and death. Fresh frozen plasma (FFP) administration is often necessary to treat coagulation disorders associated with TBI. This study aimed to determine the relationship between the presence of extravascular leakage on contrast-enhanced head CT, fibrinogen level at admission, and FFP administration in patients with TBI. The medical records of patients with TBI ≥18 years of age referred to our hospital between January 2010 and December 2020 were examined retrospectively. Patients who underwent contrast-enhanced CT immediately after admission were selected, and the presence or absence of extravascular leakage, fibrinogen level at admission, and percentage of patients who required FFP administration within 24 h of admission were examined; 172 patients were included. Multi-variable linear regression analysis was performed to determine the effects of contrast extravasation on fibrinogen levels at admission and was adjusted for age, sex, systolic blood pressure, time from injury to admission, Marshall CT score, Glasgow Coma Scale score at admission, Injury Severity Score, and need for emergency surgery; the regression coefficient was -19.8. The effect of extravasation on FFP administration within 24 h of admission was analyzed using logistic regression while adjusting for age, systolic blood pressure, Marshall CT score, need for emergency surgery, and fibrinogen level at admission. The odds ratio of contrast extravasation was 7.08 after adjustment. Extravascular leakage is associated with fibrinogen levels at admission and FFP administration within 24 h of admission.

Hyperfibrinolysis and fibrinolysis shutdown in patients with traumatic brain injury

Traumatic brain injury (TBI) is associated with coagulation/fibrinolysis disorders. We retrospectively evaluated 61 TBI cases transported to hospital within 1 h post-injury. Levels of thrombin-antithrombin III complex (TAT), D-dimer, and plasminogen activator inhibitor-1 (PAI-1) were measured on arrival and 3 h, 6 h, 12 h, 1 day, 3 days and 7 days after injury. Multivariate logistic regression analysis was performed to identify prognostic factors for coagulation and fibrinolysis. Plasma TAT levels peaked at admission and decreased until 1 day after injury. Plasma D-dimer levels increased, peaking up to 3 h after injury, and decreasing up to 3 days after injury. Plasma PAI-1 levels increased up to 3 h after injury, the upward trend continuing until 6 h after injury, followed by a decrease until 3 days after injury. TAT, D-dimer, and PAI-1 were elevated in the acute phase of TBI in cases with poor outcome. Multivariate logistic regression analysis showed that D-dimer elevation from admission to 3 h after injury and PAI-1 elevation from 6 h to 1 day after injury were significant negative prognostic indicators. Post-TBI hypercoagulation, fibrinolysis, and fibrinolysis shutdown were activated consecutively. Hyperfibrinolysis immediately after injury and subsequent fibrinolysis shutdown were associated with poor outcome.

Neurointensive Care of Traumatic Brain Injury Patients Based on Coagulation and Fibrinolytic Parameter Monitoring

Coagulopathy, a common complication of traumatic brain injury (TBI), is characterized by a hypercoagulable state developing immediately after injury, with hyperfibrinolysis and bleeding tendency peaking 3 h after injury, followed by fibrinolysis shutdown. Reflecting this timeframe, the coagulation factor fibrinogen is first consumed and then degraded after TBI, its concentration rapidly decreasing by 3 h post-TBI. The fibrinolytic marker D-dimer reaches its maximum concentration at the same time. Hyperfibrinolysis in the acute phase of TBI is associated with poor prognosis via hematoma expansion. In the acute phase, the coagulation and fibrinolysis parameters must be monitored to determine the treatment strategy. The combination of D-dimer plasma level at admission and the level of consciousness upon arrival at the hospital can be used to predict the patients who will "talk and deteriorate." Fibrinogen and D-dimer levels should determine case selection and the amount of fresh frozen plasma required for transfusion. Surgery around 3 h after injury, when fibrinolysis and bleeding diathesis peak, should be avoided if possible. In recent years, attempts have been made to estimate the time of injury from the time course of coagulation and fibrinolysis parameter levels, which has been particularly useful in some cases of pediatric abusive head trauma patients.

Development and validation of a prediction nomogram for a 6-month unfavorable prognosis in traumatic brain-injured patients undergoing primary decompressive craniectomy: An observational study

Objective

This study was designed to develop and validate a risk-prediction nomogram to predict a 6-month unfavorable prognosis in patients with traumatic brain-injured (TBI) undergoing primary decompressive craniectomy (DC).

Methods

The clinical data of 391 TBI patients with primary DC who were admitted from 2012 to 2020 were reviewed, from which 274 patients were enrolled in the training group, while 117 were enrolled in the internal validation group, randomly. The external data sets containing 80 patients were obtained from another hospital. Independent predictors of the 6-month unfavorable prognosis were analyzed using multivariate logistic regression. Furthermore, a nomogram prediction model was constructed using R software. After evaluation of the model, internal and external validations were performed to verify the efficiency of the model using the area under the receiver operating characteristic curves and the calibration plots.

Results

In multivariate analysis, age(p = 0.001), Glasgow Score Scale (GCS) (p < 0.001), operative blood loss of >750 ml (p = 0.045), completely effaced basal cisterns (p < 0.001), intraoperative hypotension(p = 0.001), and activated partial thromboplastin time (APTT) of >36 (p = 0.012) were the early independent predictors for 6-month unfavorable prognosis in patients with TBI after primary DC. The AUC for the training, internal, and external validation cohorts was 0.93 (95%CI, 0.89–0.96, p < 0.0001), 0.89 (95%CI, 0.82–0.94, p < 0.0001), and 0.90 (95%CI, 0.84–0.97, p < 0.0001), respectively, which indicated that the prediction model had an excellent capability of discrimination. Calibration of the model was exhibited by the calibration plots, which showed an optimal concordance between the predicted 6-month unfavorable prognosis probability and actual probability in both training and validation cohorts.

Conclusion

This prediction model for a 6-month unfavorable prognosis in patients with TBI undergoing primary DC can evaluate the prognosis accurately and enhance the early identification of high-risk patients.

Development and Verification of Prognostic Prediction Models for Patients with Brain Trauma Based on Coagulation Function Indexes

Objective

To assess the effect of adding coagulation indices to the currently existing prognostic prediction models of traumatic brain injury (TBI) in the prediction of outcome.

Methods

A total of 210 TBI patients from 2017 to 2019 and 131 TBI patients in 2020 were selected for development and internal verification of the new model. The primary outcomes include death at 14 days and Glasgow Outcome Score (GOS) at 6 months. The performance of each model is evaluated by means of discrimination (area under the curve (AUC)), calibration (Hosmer-Lemeshow (H-L) goodness-of-fit test), and precision (Brier score).

Results

The IMPACT Core model showed better prediction ability than the CRASH Basic model. Adding one coagulation index at a time to the IMPACT Core model, the new combined models IMPACT Core+FIB and IMPACT Core+APTT are optimal for the 6-month unfavorable outcome and 6-month mortality, respectively (AUC, 0.830 and 0.878). The new models were built based on the regression coefficients of the models. Internal verification indicated that for the prediction of 6-month unfavorable outcome and 6-month mortality, both the IMPACT Core+FIB model and the IMPACT Core+APTT model show better discrimination (AUC, 0.823 vs. 0.818 and 0.853 vs. 0.837), better calibration (HL, p = 0.114 and p = 0.317) and higher precision (Brier score, 0.148 vs. 0.141 and 0.147 vs. 0.164), respectively, than the original models.

Conclusion

Our research shows that the combination of the traumatic brain injury prognostic models and coagulation indices can improve the 6-month outcome prediction of patients with TBI.

Effects of antifibrinolytics on systemic and cerebral inflammation after traumatic brain injury

BACKGROUND

Administration of antifibrinolytic medications, including tranexamic acid (TXA), may reduce head injury-related mortality. The effect of these medications on post-traumatic brain injury (TBI) inflammatory response is unknown. The goal of this study was to investigate the role of available antifibrinolytic medications on both systemic and cerebral inflammation after TBI.

METHODS

An established murine weight drop model was used to induce a moderate TBI. Mice were administered 1, 10, or 100 mg/kg of TXA, 400 mg/kg of aminocaproic acid (Amicar, Hospira, Lake Forest, IL), 100 kIU/kg of aprotonin, or equivalent volume of normal saline (NS) 10 minutes after recovery. Mice were euthanized at 1, 6, or 24 hours. Serum and cerebral tissue were analyzed for neuron-specific enolase and inflammatory cytokines. Hippocampal histology was evaluated at 30 days for phosphorylated tau accumulation.

RESULTS

One hour after TBI, mice given TXA displayed decreased cerebral cytokine concentrations of tumor necrosis factor α (TNF-α) and, by 24 hours, displayed decreased concentrations of cerebral TNF-α, interleukin (IL)-6, and monocyte chemoattractant protein 1 compared with TBI-NS. However, serum concentrations of TNF-α and macrophage inflammatory protein 1α (MIP-1α) were significantly elevated from 1 to 24 hours in TBI-TXA groups compared with TBI-NS. The concentration of phosphorylated tau was significantly decreased in a dose-dependent manner in TBI-TXA groups compared with TBI-NS. By contrast, Amicar administration increased cerebral cytokine levels of IL-6 1 hour after TBI, with serum elevations noted in TNF-α, MIP-1α, and monocyte chemoattractant protein 1 at 24 hours compared with TBI-NS. Aprotonin administration increased serum TNF-α, IL-6, and MIP-1α from 1 to 24 hours without differences in cerebral cytokines compared with TBI-NS.

CONCLUSION

Tranexamic acid administration may provide acute neuroinflammatory protection in a dose-dependent manner. Amicar administration may be detrimental after TBI with increased cerebral and systemic inflammatory effects. Aprotonin administration may increase systemic inflammation without significant contributions to neuroinflammation. While no antifibrinolytic medication improved systemic inflammation, these data suggest that TXA may provide the most beneficial inflammatory modulation after TBI.

Association of Histones With Coagulofibrinolytic Responses and Organ Dysfunction in Adult Post-cardiac Arrest Syndrome

Background

Patients successfully resuscitated from cardiac arrest often develop organ dysfunction caused by systemic inflammation and increased coagulation, leading to disseminated intravascular coagulation (DIC). The involvement of histones in DIC and organ dysfunction in patients with sepsis and trauma has been previously reported, raising the probability that histones may also be associated with pathophysiology in patients after cardiac arrest and resuscitation. This study evaluated the relationship between histones and organ dysfunction related to coagulofibrinolytic changes in patients with post-cardiac arrest syndrome (PCAS).

Methods

This prospective single-center observational study assessed 35 adult patients with PCAS who were divided into two groups, i.e., 15 patients with multiple organ dysfunction syndrome (MODS) and 20 patients without MODS. MODS was defined as a sequential organ failure assessment score of ≥12. The plasma levels of histones and coagulofibrinolytic markers, including soluble fibrin, tissue-type plasminogen activator, plasminogen activator inhibitor-1, plasmin-alpha 2-plasmin inhibitor complex (PIC), and soluble thrombomodulin, were measured in patients with PCAS immediately after admission to the emergency department, and 3 and 24 h after arriving at the hospital.

Results

PCAS patients with MODS had higher DIC scores [4 (3.0–5.0) vs. 1 (0.0–3.0), p = 0.012] and higher mortality rates (66.7% vs. 20.0%, p = 0.013) than those without MODS. Moreover, patients with MODS exhibited higher histone levels than those without MODS during the early phase of the post-resuscitation period. Severe endothelial injury and higher thrombin and plasmin generation were observed in the MODS group. Plasma levels of histones were positively correlated with those of soluble fibrin immediately after resuscitation (rho = 0.367, p = 0.030) and PIC 3 h after arriving at the hospital (rho = 0.480, p = 0.005). This correlation was prominent in the patient population with MODS (soluble fibrin: rho = 0.681, p = 0.005, PIC: rho = 0.742, p = 0.002).

Conclusions

This study demonstrated that elevated histone levels were associated with increased levels of thrombin, and subsequent plasmin generation in PCAS patients, especially those with MODS. Further studies are required to elucidate the causal relationship between histones and organ dysfunction related to DIC in PCAS.

Biomarkers in Moderate to Severe Pediatric Traumatic Brain Injury: A Review of the Literature

BACKGROUND

Despite decades of research, outcomes in pediatric traumatic brain injury (pTBI) remain highly variable. Brain biofluid-specific biomarkers from pTBI patients may allow us to diagnose and prognosticate earlier and with a greater degree of accuracy than conventional methods. This manuscript reviews the evidence surrounding current brain-specific biomarkers in pTBI and assesses the temporal relationship between the natural history of the traumatic brain injury (TBI) and measured biomarker levels.

METHODS

A literature search was conducted in the Ovid, PubMed, MEDLINE, and Cochrane databases seeking relevant publications. The study selection and screening process were documented in a Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram. Extraction forms included developmental stages of patients, type and biofluid source of biomarkers, brain injury type, and other relevant data.

RESULTS

The search strategy identified 443 articles, of which 150 examining the biomarkers of our interest were included. The references retrieved were examined thoroughly and discussed at length with a pediatric neurocritical care intensivist specializing in pTBI and a Ph.D. scientist with a high degree of involvement in TBI biomarker research, authoring a vast amount of literature in this field.

CONCLUSIONS

TBI biomarkers might serve as valuable tools in the diagnosis and prognosis of pTBI. However, while each biomarker has its advantages, they are not without limitations, and therefore, further research is critical in pTBI biomarkers.

Coagulopathy and Traumatic Brain Injury: Overview of New Diagnostic and Therapeutic Strategies

Coagulopathy is a common sequela of traumatic brain injury. Consumptive coagulopathy and secondary hyperfibrinolysis are associated with hypercoagulability. In addition, fibrinolytic pathways are hyperactivated as a result of vascular endothelial cell damage in the injured brain. Coagulation and fibrinolytic parameters change dynamically to reflect these pathologies. Fibrinogen is consumed and degraded after injury, with fibrinogen concentrations at their lowest 3-6 h after injury. Hypercoagulability causes increased fibrinolytic activity, and plasma levels of D-dimer increase immediately after traumatic brain injury, reaching a maximum at 3 h. Owing to disseminated intravascular coagulation in the presence of fibrinolysis, the bleeding tendency is highest within the first 3 h after injury, and often a condition called “talk and deteriorate” occurs. In neurointensive care, it is necessary to measure coagulation and fibrinolytic parameters such as fibrinogen and D-dimer routinely to predict and prevent the development of coagulopathy and its negative outcomes. Currently, the only evidence-based treatment for traumatic brain injury with coagulopathy is tranexamic acid in the subset of patients with mild-to-moderate traumatic brain injury. Coagulation and fibrinolytic parameters should be closely monitored, and treatment should be considered on a patient-by-patient basis.

Early thrombocytopenia is associated with an increased risk of mortality in patients with traumatic brain injury treated in the intensive care unit: a Finnish Intensive Care Consortium study

BACKGROUND

Coagulopathy after traumatic brain injury (TBI) is associated with poor prognosis.

PURPOSE

To assess the prevalence and association with outcomes of early thrombocytopenia in patients with TBI treated in the intensive care unit (ICU).

METHODS

This is a retrospective multicenter study of adult TBI patients admitted to ICUs during 2003-2019. Thrombocytopenia was defined as a platelet count < 100 × 10⁹/L during the first day. The association between thrombocytopenia and hospital and 12-month mortality was tested using multivariable logistic regression, adjusting for markers of injury severity.

RESULTS

Of 4419 patients, 530 (12%) had early thrombocytopenia. In patients with thrombocytopenia, hospital and 12-month mortality were 26% and 48%, respectively; in patients with a platelet count > 100 × 10⁹/L, they were 9% and 22%, respectively. After adjusting for injury severity, a higher platelet count was associated with decreased odds of hospital mortality (OR 0.998 per unit, 95% CI 0.996-0.999) and 12-month mortality (OR 0.998 per unit, 95% CI 0.997-0.999) in patients with moderate-to-severe TBI. Compared to patients with a normal platelet count, patients with thrombocytopenia not receiving platelet transfusion had an increased risk of 12-month mortality (OR 2.2, 95% CI 1.6-3.0), whereas patients with thrombocytopenia receiving platelet transfusion did not (OR 1.0, 95% CI 0.6-1.7).

CONCLUSION

Early thrombocytopenia occurs in approximately one-tenth of patients with TBI treated in the ICU, and it is an independent risk factor for mortality in patients with moderate-to-severe TBI. Further research is necessary to determine whether this is modifiable by platelet transfusion.

Effect of tranexamic acid on the prognosis of patients with traumatic brain injury undergoing craniotomy: study protocol for a randomised controlled trial

INTRODUCTION

Abnormal coagulation function aggravates the prognosis of patients with traumatic brain injury (TBI). It was reported that the antifibrinolytic drug tranexamic acid (TXA) could reduce intracranial haemorrhage and mortality in non-operative patients with TBI. However, there is a lack of evaluation of TXA in patients with TBI undergoing craniotomy.

METHODS AND ANALYSIS

This is a single-centre randomised controlled, double-blind, parallel study aiming to investigate the effectiveness and safety of TXA in patients with TBI during the perioperative period. Blood loss and transfusion, neurological function, adverse events, mortality and serum immune-inflammatory cytokines will be collected and analysed.

ETHICS AND DISSEMINATION

Ethical approval has been granted by the Medical Ethics Committee of Beijing Tian Tan Hospital, Capital Medical University (reference number KY 2020-136-03). The results of this study will be disseminated through presentations at scientific conferences and publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR2100041911.

Time course of coagulation and fibrinolytic parameters in pediatric traumatic brain injury

OBJECTIVE

Coagulopathy is a well-recognized risk factor for poor outcomes in patients with traumatic brain injury (TBI). Differences in the time courses of coagulation and fibrinolytic parameters between pediatric and adult patients with TBI have not been defined.

METHODS

Patients with TBI and an Abbreviated Injury Scale of the head score ≥ 3, in whom the prothrombin time (PT)-international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen concentration, and plasma D-dimer levels were measured on arrival and at 3, 6, and 12 hours after injury, were retrospectively analyzed. Propensity score-matched analyses were performed to adjust baseline characteristics between pediatric patients (aged < 16 years) and adult patients (aged ≥ 16 years).

RESULTS

A total of 468 patients (46 children and 422 adults) were included. Propensity score matching resulted in a matched cohort of 46 pairs. Higher PT-INR and APTT values at 1 to 12 hours after injury and lower fibrinogen concentrations at 1 to 6 hours after injury were observed in the pediatric group compared with the adult group. Plasma levels of D-dimer were elevated in both groups at 1 to 12 hours after injury, but no significant differences were seen between the groups. Multivariate logistic regression analysis of the initial coagulation and fibrinolytic parameters in the pediatric group revealed no prognostic significance of the coagulation parameter values, but elevation of the fibrinolytic parameter D-dimer was an independent negative prognostic factor.

CONCLUSIONS

In the acute phase of TBI, pediatric patients were characterized by prolongation of PT-INR and APTT and lower fibrinogen concentrations compared with adult patients, but these did not correlate with outcome. D-dimer was an independent prognostic outcome factor in terms of the Glasgow Outcome Scale in pediatric patients with TBI.

Viscoelastic Testing in Traumatic Brain Injury: Key Research Insights

The role of viscoelastic testing in the evaluation and management of traumatic brain injury (TBI) remains a subject of ongoing exploration. This review highlights four key publications that provide significant insights into this subject. Holcomb et al. provided early evidence of the relationship between thromboelastography (TEG) and conventional coagulation tests (CCTs). Later, Samuels et al. used TEG to identify a unique coagulopathy phenotype in TBI characterized by a notable absence of fibrinolytic abnormalities. Dixon et al. built upon these findings by exploring the application of TEG in the context of antifibrinolytic administration, noting a similar lack of effect on LY30. Finally, Guillotte et al. demonstrated the utility of TEG-PM in assessing platelet dysfunction in TBI. While these studies provide key early support for the utility of viscoelastic testing in the TBI, further exploration is needed to define evidence-based guidelines for clinical application.

Biofluid Biomarkers in Traumatic Brain Injury: A Systematic Scoping Review

Emerging evidence suggests that biofluid-based biomarkers have diagnostic and prognostic potential in traumatic brain injuries (TBI). However, owing to the lack of a conceptual framework or comprehensive review, it is difficult to visualize the breadth of materials that might be available. We conducted a systematic scoping review to map and categorize the evidence regarding biofluid-based biochemical markers of TBI. A comprehensive search was undertaken in January 2019. Of 25,354 records identified through the literature search, 1036 original human studies were included. Five hundred forty biofluid biomarkers were extracted from included studies and classified into 19 distinct categories. Three categories of biomarkers including cytokines, coagulation tests, and nerve tissue proteins were investigated more than others and assessed in almost half of the studies (560, 515, and 502 from 1036 studies, respectively). S100 beta as the most common biomarker for TBI was tested in 21.2% of studies (220 articles). Cortisol was the only biomarker measured in blood, cerebrospinal fluid, urine, and saliva. The most common sampling time was at admission and within 24 h of injury. The included studies focused mainly on biomarkers from blood and central nervous system sources, the adult population, and severe and blunt injuries. The most common outcome measures used in studies were changes in biomarker concentration level, Glasgow coma scale, Glasgow outcome scale, brain computed tomography scan, and mortality rate. Biofluid biomarkers could be clinically helpful in the diagnosis and prognosis of TBI. However, there was no single definitive biomarker with accurate characteristics. The present categorization would be a road map to investigate the biomarkers of the brain injury cascade separately and detect the most representative biomarker of each category. Also, this comprehensive categorization could provide a guiding framework to design combined panels of multiple biomarkers.

Mannose-binding lectin promotes blood-brain barrier breakdown and exacerbates axonal damage after traumatic brain injury in mice

Leukocyte infiltration and blood-brain barrier breakdown contribute to secondary brain damage after traumatic brain injury (TBI). TBI induces neuroimmune responses triggering pathogenic complement activation through different pathways, including the lectin pathway. We investigated mechanisms underlying mannose-binding lectin (MBL)-mediated brain damage focusing on neutrophil infiltration and blood-brain barrier breakdown in a TBI mouse model. Wild type mice and MBL^-/- null mice were subjected to controlled cortical impact. We studied neutrophil infiltration and regional localization by confocal microscopy 1, 4 and 15 days post-trauma, and investigated neutrophil extracellular trap (NET) formation. By immunofluorescence and/or Western blotting in various brain regions we studied the presence of fibrin(ogen), pentraxin-3, albumin and immunoglobulin G. Finally, we studied neurofilament proteins, synaptophysin, and αII-spectrin, and assessed white matter content in the injured tissue. TBI triggered an acute wave of neutrophil infiltration at day 1 followed by a more discrete persistence of neutrophils in the injured tissue at least until day 15. We detected the presence of NETs and pentraxin-3 in the injured tissue, as well as accumulation of fibrin(ogen), increased blood-brain barrier permeability, and neurofilament, synaptophysin and white matter loss, and calpain-mediated αII spectrin breakdown. MBL^-/- mice showed reduced number of Ly6G⁺ neutrophils 4 days after TBI, lower accumulation of pentraxin-3 and fibrin(ogen) in the injured tissue, reduced global plasma protein extravasation, and better preservation of axonal and white matter integrity. These results show that MBL participates in secondary neutrophil accumulation and blood-brain barrier breakdown, and promotes axonal and white matter damage after TBI in mice.

The Association Between D-dimer Levels and Long-Term Neurological Outcomes of Patients with Traumatic Brain Injury: An Analysis of a Nationwide Observational Neurotrauma Database in Japan

BACKGROUND

We evaluated the association between D-dimer (DD) levels and long-term neurological prognoses among patients with isolated traumatic brain injury.

METHODS

Using data from multiple centers in the Japanese Neurotrauma Data Bank, we conducted an observational retrospective cohort study. Patients with isolated traumatic brain injury (head Abbreviated Injury Scale score > 2; any other Abbreviated Injury Scale score < 3) who were registered in the Japanese Neurotrauma Data Bank from 2015 to 2017 were recruited. We excluded patients younger than age 16 years and those who developed cardiac arrest at hospital admission. We also excluded patients with unknown Glasgow Outcome Scale (GOS) scores at 6 months after injury and those with unknown DD levels. The primary outcome was the association of DD levels with GOS scores at 6 months. We defined GOS scores 1 to 3 as poor and GOS scores 4 and 5 as good. The secondary outcome was the association of DD levels with mortality at 6 months after injury. We conducted multivariate logistic regression analyses to calculate the adjusted odds ratios of DD levels at hospital admission and GOS scores at 6 months as tertiles with 95% confidence intervals (CIs). A total of 293 patients were enrolled (median age 67 years; interquartile range 51-79 years). The median DD level was 27.1 mg/L (interquartile range 9.7-70.8 mg/L), and 58.0% (n = 170) had poor GOS scores at 6 months.

RESULTS

The multivariable logistic regression analysis indicated that the adjusted odds ratios were 2.52 (95% CI 1.10-5.77) for middle DD levels with poor GOS scores at 6 months and 5.81 (95% CI 2.37-14.2) for high DD levels with poor GOS scores at 6 months.

CONCLUSIONS

We revealed an association between DD levels and poor long-term neurological outcomes among patients with isolated traumatic brain injury.

Neutrophil to lymphocyte ratio predicts early growth of traumatic intracerebral haemorrhage

OBJECTIVE

The neutrophil to lymphocyte ratio (NLR) has been proposed to capture the inflammatory status of patients with various conditions involving the brain. This retrospective study aimed to explore the association between the NLR and the early growth of traumatic intracerebral haemorrhage (tICH) in patients with traumatic brain injury (TBI).

METHODS

A multicentre, observational cohort study was conducted. Patients with cerebral contusion undergoing baseline computed tomography for haematoma volume analysis within 6 h after primary injury and follow-up visits within 48 h were included. Routine blood tests were performed upon admission, and early growth of tICH was assessed. Prediction accuracies of the NLR for the early growth of tICH and subsequent surgical intervention in patients were analysed.

RESULTS

There were a total of 1077 patients who met the criteria included in the study cohort. Univariate analysis results showed that multiple risk factors were associated with the early growth of tICH and included in the following multivariate analysis models. The multivariate logistic regression analysis results revealed that the NLR was highly associated with the early growth of tICH (p < 0.001) while considering other risk factors in the same model. The prediction accuracy of the NLR for the early growth of tICH in patients is 82%.

INTERPRETATION

The NLR is easily calculated and might predict the early growth of tICH for patients suffering from TBI.

Relationship between admission coagulopathy and prognosis in children with traumatic brain injury: a retrospective study

BACKGROUND

Coagulopathy in adult patients with traumatic brain injury (TBI) is strongly associated with unfavorable outcomes. However, few reports focus on pediatric TBI-associated coagulopathy.

METHODS

We retrospectively identified children with Glasgow Coma Scale ≤ 13 in a tertiary pediatric hospital from April 2012 to December 2019 to evaluate the impact of admission coagulopathy on their prognosis. A classification and regression tree (CART) analysis using coagulation parameters was performed to stratify the death risk among patients. The importance of these parameters was examined by multivariate logistic regression analysis.

RESULTS

A total of 281 children with moderate to severe TBI were enrolled. A receiver operating characteristic curve showed that activated partial thromboplastin time (APTT) and fibrinogen were effective predictors of in-hospital mortality. According to the CART analysis, APTT of 39.2 s was identified as the best discriminator, while 120 mg/dL fibrinogen was the second split in the subgroup of APTT ≤ 39.2 s. Patients were stratified into three groups, in which mortality was as follows: 4.5 % (APTT ≤ 39.2 s, fibrinogen > 120 mg/dL), 20.5 % (APTT ≤ 39.2 s and fibrinogen ≤ 120 mg/dL) and 60.8 % (APTT > 39.2 s). Furthermore, length-of-stay in the ICU and duration of mechanical ventilation were significantly prolonged in patients with deteriorated APTT or fibrinogen values. Multiple logistic regression analysis showed that APTT > 39.2 s and fibrinogen ≤ 120 mg/dL was independently associated with mortality in children with moderate to severe TBI.

CONCLUSIONS

We concluded that admission APTT > 39.2 s and fibrinogen ≤ 120 mg/dL were independently associated with mortality in children with moderate to severe TBI. Early identification and intervention of abnormal APTT and fibrinogen in pediatric TBI patients may be beneficial to their prognosis.

Fibrinolysis in Traumatic Brain Injury: Diagnosis, Management, and Clinical Considerations

Posttraumatic coagulopathy involves disruption of both the coagulation and fibrinolytic pathways secondary to tissue damage, hypotension, and inflammatory upregulation. This phenomenon contributes to delayed complications after traumatic brain injury (TBI), including intracranial hemorrhage progression and systemic disseminated intravascular coagulopathy. Development of an early hyperfibrinolytic state may result in uncontrolled bleeding and is associated with increased mortality in patients with TBI. Although fibrinolytic assays are not routinely performed in the assessment of posttraumatic coagulopathy, circulating biomarkers such as D-dimer and fibrin degradation products have demonstrated potential utility in outcome prediction. Unfortunately, the relatively delayed nature of these tests limits their clinical utility. In contrast, viscoelastic tests are able to provide a rapid global assessment of coagulopathy, although their ability to reliably identify disruptions in the fibrinolytic cascade remains unclear. Limited evidence supports the use of hypertonic saline, cryoprecipitate, and plasma to correct fibrinolytic disruption; however, some studies suggest more harm than benefit. Recently, early use of tranexamic acid in patients with TBI and confirmed hyperfibrinolysis has been proposed as a strategy to further improve clinical outcomes. Moving forward, further delineation of TBI phenotypes and the clinical implications of fibrinolysis based on phenotypic variation is needed. In this review, we summarize the clinical aspects of fibrinolysis in TBI, including diagnosis, treatment, and clinical correlates, with identification of targeted areas for future research efforts.

Combined Strategy of Burr Hole Surgery and Elective Craniotomy under Intracranial Pressure Monitoring for Severe Acute Subdural Hematoma

Burr hole surgery in the emergency room can be lifesaving for patients with acute subdural hematoma (ASDH). In the first part of this study, a strategy of combined burr hole surgery, a period of intracranial pressure (ICP) monitoring, and then craniotomy was examined for safe and effective treatment of ASDH. Since 2012, 16 patients with severe ASDH with indications for burr hole surgery were admitted to Kenwakai Otemachi Hospital. From 2012 to 2016, craniotomy was performed immediately after burr hole surgery (emergency [EM] group, n = 10). From 2017, an ICP sensor was placed before burr hole surgery. After a period for correction of traumatic coagulopathy, craniotomy was performed when ICP increased (elective [EL] group, n = 6). Patient background, bleeding tendency, intraoperative blood transfusion, and outcomes were compared between the groups. In the second part of the study, ICP was measured before and after burr hole surgery in seven patients (including two of the six in the EL group) to assess the effect of this surgery. Activated partial thromboplastin time (APTT) and prothrombin time-international normalized ratio (PT-INR) were significantly prolonged after craniotomy in the EM group, but not in the EL group, and the EM group tended to require a higher intraoperative transfusion volume. The rate of good outcomes was significantly higher in the EL group, and ICP was significantly decreased after burr hole surgery. These results suggest the value of burr hole surgery followed by ICP monitoring in patients with severe ASDH. Craniotomy can be performed safely using this method, and this may contribute to improved outcomes.

Time Course of Hemostatic Disruptions After Traumatic Brain Injury: A Systematic Review of the Literature

Almost two-thirds of patients with severe traumatic brain injury (TBI) develop some form of hemostatic disturbance, which contributes to poor outcome. While the initial head injury often leads to impaired clot formation, TBI is also associated with an increased risk of thrombosis. Most likely there is a progression from early bleeding to a later prothrombotic state. In this paper, we systematically review the literature on the time course of hemostatic disruptions following TBI. A MEDLINE search was performed for TBI studies reporting the trajectory of hemostatic assays over time. The search yielded 5,049 articles, of which 4,910 were excluded following duplicate removal as well as title and abstract review. Full-text assessment of the remaining articles yielded 33 studies that were included in the final review. We found that the first hours after TBI are characterized by coagulation cascade dysfunction and hyperfibrinolysis, both of which likely contribute to lesion progression. This is then followed by platelet dysfunction and decreased platelet count, the clinical implication of which remains unclear. Later, a poorly defined prothrombotic state emerges, partly due to fibrinolysis shutdown and hyperactive platelets. In the clinical setting, early administration of the antifibrinolytic agent tranexamic acid has proved effective in reducing head-injury-related mortality in a subgroup of TBI patients. Further studies evaluating the time course of hemostatic disruptions after TBI are warranted in order to identify windows of opportunity for potential treatment options.

Trauma-Induced Coagulopathy: Overview of an Emerging Medical Problem from Pathophysiology to Outcomes

Coagulopathy induced by major trauma is common, affecting approximately one-third of patients after trauma. It develops independently of iatrogenic, hypothermic, and dilutive causes (such as iatrogenic cause in case of fluid administration), which instead have a pejorative aspect on coagulopathy. Notwithstanding the continuous research conducted over the past decade on Trauma-Induced Coagulopathy (TIC), it remains a life-threatening condition with a significant impact on trauma mortality. We reviewed the current evidence regarding TIC diagnosis and pathophysiological mechanisms and summarized the different iterations of optimal TIC management strategies among which product resuscitation, potential drug administrations, and hemostatis-focused approaches. We have identified areas of ongoing investigation and controversy in TIC management.

Hemorrhage Expansion After Pediatric Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

Significant hemorrhage expansion (sHE) is a known predictor of poor outcome after an intracerebral hemorrhage (ICH) in adults but remains poorly reported in children. In a large inception cohort, we aimed to explore the prevalence of sHE, its associations with clinical outcomes, and its clinical-imaging predictors in children.

METHODS

Children admitted between January 2000 and March 2020 at a quaternary care pediatric hospital were screened for inclusion. Sample was restricted to children with 2 computed tomography scans within 72 hours of ICH onset, and a minimal clinical follow-up of months. sHE was defined as an increase from baseline ICH volume by 6 cc or 33% on follow-up computed tomography. Clinical outcome was assessed at 12 months with the King's Outcome Scale for Childhood Head Injury score and defined as favorable for scores ≥5.

RESULTS

Fifty-two children met inclusion criteria, among which 8 (15%) demonstrated sHE, and 18 (34.6%) any degree of expansion. Children with sHE had more frequent coagulation disorders (25.0% versus 2.3%; P=0.022). After multivariable adjustment, only the presence of coagulation disorders at baseline remained independently associated with sHE (adjusted odds ratio, 14.4 [95% CI, 1.04-217]; P=0.048). sHE was independently associated with poor outcome (King's Outcome Scale for Childhood Head Injury <5A, odds ratio, 5.77 [95% CI, 1.01-38.95]; P=0.043).

CONCLUSIONS

sHE is a frequent phenomenon after admission for a pediatric ICH and more so in children with coagulation defects. As sHE was strongly associated with poorer clinical outcomes, these data mandate a baseline coagulation work up and questions the need for protocolized repeat head computed tomography in children admitted for pediatric ICH.

Clinical predictors of prognosis in patients with traumatic brain injury combined with extracranial trauma

Objective: The purpose of this study was to investigate whether routine blood tests on admission and clinical characteristics can predict prognosis in patients with traumatic brain injury (TBI) combined with extracranial trauma. Methods: Clinical data of 182 patients with TBI combined with extracranial trauma from April 2018 to December 2019 were retrospectively collected and analyzed. Based on GOSE score one month after discharge, the patients were divided into a favorable group (GOSE 1-4) and unfavorable group (GOSE 5-8). Routine blood tests on admission and clinical characteristics were recorded. Results: Overall, there were 48 (26.4%) patients with unfavorable outcome and 134 (73.6%) patients with favorable outcome. Based on multivariate analysis, independent risk factors associated with unfavorable outcome were age (odds ratio [OR], 1.070; 95% confidence interval [CI], 1.018-1.124; p<0.01), admission Glasgow Coma Scale (GCS) score (OR, 0.807; 95% CI, 0.675-0.965; p<0.05), heart rate (OR, 1.035; 95% CI, 1.004-1.067; p<0.05), platelets count (OR, 0.982; 95% CI, 0.967-0.997; p<0.05), and tracheotomy (OR, 15.201; 95% CI, 4.121-56.078; p<0.001). Areas under the curve (AUC) of age, admission GCS, heart rate, tracheotomy, and platelets count were 0.678 (95% CI, 0.584-0.771), 0.799 (95% CI, 0.723-0.875), 0.652 (95% CI, 0.553-0.751), 0.776 (95% CI, 0.692-0.859), and 0.688 (95% CI, 0.606-0.770), respectively. Conclusions: Age, admission GCS score, heart rate, tracheotomy, and platelets count can be recognized as independent predictors of clinical prognosis in patients with severe TBI combined with extracranial trauma.

Factors associated with the progression of traumatic intracranial hematoma during interventional radiology to establish hemostasis of extracranial hemorrhagic injury in severe multiple trauma patients

Aim

To identify factors affecting the progression of traumatic intracranial hemorrhagic injury (t‐ICH) during interventional radiology (IVR) for the hemostasis of extracranial hemorrhagic injury.

Methods

This was a retrospective comparative study. Fifty‐two patients with t‐ICH who underwent hemostasis using IVR for extracranial trauma at our institute were included. Clinical and computed tomography scan data were collected to investigate factors associated with t‐ICH progression.

Results

Fifty‐two subjects (36 men/16 women) with a mean age of 70.9 ± 19.2 years were analyzed. The mean Injury Severity Score was 34.9 ± 11.2. In 29 patients (55.7%), t‐ICH progressed during IVR. Hematoma progression frequently occurred in patients with acute subdural hematoma (56.2%) and traumatic intracerebral hematoma/hemorrhagic brain contusion (66.6%). Factors associated with t‐ICH progression included age (P = 0.029), consciousness level at admission (P = 0.001), Revised Trauma Scale (P = 0.036), probability of survival (P = 0.043), platelet count (P = 0.005), fibrinogen level (P = 0.016), hemoglobin level (P = 0.003), D‐dimer level (P = 0.046), and red blood cell transfusion volume (P = 0.023).

Conclusion

Aggressive correction of anemia, thrombocytopenia, and low fibrinogen levels in severe consciousness disturbance patients with acute subdural hematoma and traumatic intracerebral hematoma/hemorrhagic brain contusion could improve the prognosis after IVR for hemostasis of extracranial hemorrhagic injuries.

Serum Glucose-To-Potassium Ratio as a Prognostic Predictor for Severe Traumatic Brain Injury

BACKGROUND

Initial management of severe traumatic brain injury is important and includes treatment decision-making and prediction of prognosis. We examined whether biomarkers at admission could be useful prognostic predictors. We focused on electrolytes and blood glucose, which can be measured easily at any facility and for which results can be obtained promptly, before those of other biomarkers, such as D-dimer.

METHODS

All trauma patients with head injuries treated at Chiba Hokusoh Hospital between 2014 and 2017 were investigated. Cases of multiple trauma accompanied by fatal trauma, hemorrhagic shock, or cardiopulmonary arrest, and pediatric cases, were excluded from this study. Blood gas data at the initial hospital visit were reviewed retrospectively. A poor outcome was defined as death during hospitalization or a vegetative state due to head injury. Factors related to poor outcomes were analyzed.

RESULTS

Of the 185 male and 79 female patients studied, 34 had poor outcomes. Poor outcome was significantly correlated with potassium (P = 0.003), glucose (P < 0.001), and glucose-to-potassium ratio (P < 0.001) at arrival. The odds ratio was 4.079 for a glucose-to-potassium ratio of ≥50.

CONCLUSIONS

We evaluated blood gas data at the initial hospital visit, as these results can be obtained more quickly than those of other biomarkers assessed previously. Serum glucose-to-potassium ratio at admission may be a potential predictor of prognosis for severe traumatic brain injury.

Age-Related Differences in the Time Course of Coagulation and Fibrinolytic Parameters in Patients with Traumatic Brain Injury

Coagulopathy and older age are common and well-recognized risk factors for poorer outcomes in traumatic brain injury (TBI) patients; however, the relationships between coagulopathy and age remain unclear. We hypothesized that coagulation/fibrinolytic abnormalities are more pronounced in older patients and may be a factor in poorer outcomes. We retrospectively evaluated severe TBI cases in which fibrinogen and D-dimer were measured on arrival and 3–6 h after injury. Propensity score-matched analyses were performed to adjust baseline characteristics between older patients (the “elderly group,” aged ≥75 y) and younger patients (the “non-elderly group,” aged 16–74 y). A total of 1294 cases (elderly group: 395, non-elderly group: 899) were assessed, and propensity score matching created a matched cohort of 324 pairs. Fibrinogen on admission, the degree of reduction in fibrinogen between admission and 3–6 h post-injury, and D-dimer levels between admission and 3–6 h post-injury were significantly more abnormal in the elderly group than in the non-elderly group. On multivariate logistic regression analysis, independent risk factors for poor prognosis included low fibrinogen and high D-dimer levels on admission. Posttraumatic coagulation and fibrinolytic abnormalities are more severe in older patients, and fibrinogen and D-dimer abnormalities are negative predictive factors.

Fibrinogen-cellular prion protein complex formation on astrocytes

Traumatic brain injury (TBI) is one of the most common neurological disorders causing memory reduction, particularly short-term memory (STM). We showed that, during TBI-induced inflammation, increased blood content of fibrinogen (Fg) enhanced vascular protein transcytosis and deposition of extravasated Fg in vasculo-astrocyte interfaces. In addition, we found that deposition of cellular prion protein (PrP^C) was also increased in the vasculo-astrocyte endfeet interface. However, association of Fg and PrP^C was not confirmed. Presently, we aimed to define whether Fg can associate with PrP^C on astrocytes and cause their activation. Cultured mouse brain astrocytes were treated with medium alone (control), Fg (2 mg/mL or 4 mg/mL), 4 mg/mL of Fg in the presence of a function-blocking anti-PrP^C peptide or anti-mouse IgG, function-blocking anti-PrP^C peptide, or anti-mouse IgG alone. After treatment, either cell lysates were collected and analyzed via Western blot or coimmunoprecipitation was performed, or astrocytes were fixed and their activation was assessed with immunohistochemistry. Results showed that Fg dose-dependently activated astrocytes, increased expressions of PrP^C and tyrosine (tropomyosin) receptor kinase B (TrkB), and PrP gene. Blocking the function of PrP^C reduced these effects. Coimmunoprecipitation demonstrated Fg and PrP^C association. Since it is known that prion protein has a greater effect on memory reduction than amyloid beta, and that activation of TrkB is involved in neurodegeneration, our findings confirming the possible formation of Fg-PrP^C and Fg-induced overexpression of TrkB on astrocytes suggest a possible triggering mechanism for STM reduction that was seen previously during mild-to-moderate TBI.NEW & NOTEWORTHY For the first time we showed that fibrinogen (Fg) can associate with cellular prion protein (PrP^C) on the surface of cultured mouse brain astrocytes. At high levels, Fg causes upregulation of astrocyte PrP^C and astrocyte activation accompanied with overexpression of tyrosine receptor kinase B (TrkB), which results in nitric oxide (NO) production and generation of reactive oxygen species (ROS). Fg/PrP^C interaction can be a triggering mechanism for TrkB-NO-ROS axis activation and the resultant astrocyte-mediated neurodegeneration.

Efficacy and safety of tranexamic acid administration in traumatic brain injury patients: a systematic review and meta-analysis

Background

The exacerbation of intracranial bleeding is critical in traumatic brain injury (TBI) patients. Tranexamic acid (TXA) has been used to improve outcomes in TBI patient. However, the effectiveness of TXA treatment remains unclear. This study aimed to assess the effect of administration of TXA on clinical outcomes in patients with TBI by systematically reviewing the literature and synthesizing evidence of randomized controlled trials (RCTs).

Methods

MEDLINE, the Cochrane Central Register of Controlled Trials, and Igaku Chuo Zasshi (ICHUSHI) Web were searched. Selection criteria included randomized controlled trials with clinical outcomes of adult TBI patients administered TXA or placebo within 24 h after admission. Two investigators independently screened citations and conducted data extraction. The primary “critical” outcome was all-cause mortality. The secondary “important” outcomes were good neurological outcome rates, enlargement of bleeding, incidence of ischemia, and hemorrhagic intracranial complications. Random effect estimators with weights calculated by the inverse variance method were used to report risk ratios (RRs).

Results

A total of 640 records were screened. Seven studies were included for quantitative analysis. Of 10,044 patients from seven of the included studies, 5076 were randomly assigned to the TXA treatment group, and 4968 were assigned to placebo. In the TXA treatment group, 914 patients (18.0%) died, while 961 patients (19.3%) died in the placebo group. There was no significant difference between groups (RR, 0.93; 95% confidence interval, 0.86–1.01). No significant differences between the groups in other important outcomes were also observed.

Conclusions

TXA treatment demonstrated a tendency to reduce head trauma-related deaths in the TBI population, with no significant incidence of thromboembolic events. TXA treatment may therefore be suggested in the initial TBI care.

Determinants affecting the prognosis of decompressive craniectomy for traumatic brain injury

Objective:

This research was designed to investigate the prognostic determinants of patients with traumatic brain injury (TBI) undergoing decompressive craniectomy (DC).

Methods:

The present study was a retrospective single center research including a total of 112 patients undergoing DC for TBI in Liaocheng People’s Hospital between January 2017 and December 2018. The results were measured by Extended Glasgow Outcome Sale (GOSE). The prognostic determinants were identified by univariate and binary logistic regression analysis between the deaths and survivors or favorable and unfavorable outcomes.

Results:

At the six-month follow-up, the mortality was 45.5% including 37 (33.0%) patients died within 30 days. The independent prognostic factors of 30-day mortality were age (p=0.033), D-dimer level at admission (p=0.032) and postoperative hypernatremia (p=0.014). Seventy five patients survived more than 30 days after DC, among which 27 (36.0%) patients had unfavorable prognosis (GOSE 1-4) and 48 (64.0%) patients presented favorable prognosis (GOSE 5-8). After 30 days from DC, the occurrence of post-traumatic hydrocephalus(PTH) (p= 0.008) was associated with unfavorable prognosis.

Conclusions:

Although DC is an effective treatment for TBI patients, the mortality and morbidity risk remain high. A combination of age, D-dimer level at admission and postoperative hypernatremia may be a good prognostic factor for 30-day mortality. Developing an accurate therapy strategy to prevent and control PTH may be beneficial to the 6-month prognosis for TBI patients undergoing DC.

Increase in Fibrinogen Degradation Product Levels 5 Days after a Traumatic Insult

Context:

Few reports have investigated the time course of fibrinogen (or fibrin) degradation product (FDP) levels for trauma patients in the subacute phase.

Aims:

This study aimed to investigate the time course of the FDP levels among patients with moderate and severe trauma in the subacute phase.

Settings and Design:

A retrospective medical chart review in a single hospital.

Subjects and Methods:

From September 2017 to March 2018, a medical chart review was retrospectively performed for all patients with trauma who were admitted to our department, and these patients were included as participants in the present study. We collected the data on each patient's sex, age, presence of head injury, mechanism of injury, Glasgow Coma Scale on arrival, systolic blood pressure, heart rate, type of injury (blunt versus penetrating), injury severity score, complication of infection, surgical procedure, duration of admission, survival rate, and FDP level from the 1^st to 7^th hospital day. The average level of FDP on each hospital day was compared with that on the previous day.

Statistical Analysis Used:

The statistical analyses were performed using a paired Student's t-test. P < 0.05 was considered to indicate a statistically significant difference.

Results:

From the 1^st to 4^th hospital day, the average level of FDP significantly diminished day by day. However, from the 5^th hospital day, the average level significantly increased. This trend persisted even after excluding the complications of infection and surgical procedures performed between the 2^nd and 7^th hospital day.

Conclusions:

Among trauma patients, the average level of FDP significantly diminished day by day from the admission to the 4^th hospital day; however, from the 5^th hospital day, the average level significantly increased. Further studies are needed to determine the time course of FDP or D-dimer levels in the long term and when FDP levels return to normal limits.

Does Complement-Mediated Hemostatic Disturbance Occur in Traumatic Brain Injury? A Literature Review and Observational Study Protocol

Despite improvements in medical triage and tertiary care, traumatic brain injury (TBI) remains associated with significant morbidity and mortality. Almost two-thirds of patients with severe TBI develop some form of hemostatic disturbance, which contributes to poor outcome. In addition, the complement system, which is abundant in the healthy brain, undergoes significant intra- and extracranial amplification following TBI. Previously considered to be structurally similar but separate systems, evidence of an interaction between the complement and coagulation systems in non-TBI cohorts has accumulated, with the activation of one system amplifying the activation of the other, independent of their established pathways. However, it is not known whether this interaction exists in TBI. In this review we summarize the available literature on complement activation following TBI, and the crosstalk between the complement and coagulation systems. We demonstrate how the complement system interacts with the coagulation cascade by activating the intrinsic coagulation pathway and by bypassing the initial cascade and directly producing thrombin as well. This crosstalk also effects platelets, where evidence points to a relationship with the complement system on multiple levels, with complement anaphylatoxins being able to induce disproportionate platelet activation and adhesion. The complement system also stimulates thrombosis by inhibiting fibrinolysis and stimulating endothelial cells to release prothrombotic microparticles. These interactions see clinical relevance in several disorders where a deficiency in complement regulation seems to result in a prothrombotic clinical presentation. Finally, based on these observations, we present the outline of an observational cohort study that is currently under preparation and aimed at assessing how complement influences coagulation in patients with isolated TBI.

Low plasma D-dimer predicts absence of intracranial injury and skull fracture

BACKGROUND

Intracranial injury (ICI) is a leading cause of morbidity in children; however, the use of computed tomography (CT) to evaluate ICI has significant risks in children. A recent study suggests D-dimer is associated with ICI. We surveyed the performance of plasma D-dimer in ruling out ICI or skull fracture (SF) in children with head trauma.

METHODS

In a cross-sectional study in the Emergency Department (ED) at the National Center for Child Health and Development in Tokyo, Japan we reviewed the medical records of all children age 0-16 years brought to the ED with head trauma from January 2010 to July 2013, who underwent CT based on established clinical criteria and had plasma D-dimer measured. We evaluated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of plasma D-dimer, using abnormal findings on CT (ICI, SF) as the criterion standard. We repeated analysis after stratification by age (<2 years, ≥2 years).

RESULTS

Among 364 eligible children (112 children <2 year of age), abnormal findings on CT were demonstrated in 33.8% (123/364). With the cut-off set at 0.5 μg/mL, sensitivity was 100.0% (95% confidence interval [CI]: 95.6-100.0%), specificity 34.0% (95%CI: 28.1-40.4%), PPV 43.6% (95%CI: 37.7-49.6%), NPV 100.0% (95%CI: 93.5-100%). After stratification by age (<2 years and ≥2 years), sensitivity (100.0% and 100.0%) and NPV (100.0% and 100.0%) remained high in both age groups.

CONCLUSIONS

Low plasma D-dimer (≤0.5 μg/mL) is useful to limit the use of CT in children by excluding traumatic ICI or SF.

Hemostatic Balance in Severe Trauma

Acute coagulopathy is prevalent in adult and pediatric trauma patients and is associated with increased morbidity and mortality. While reasonable hypotheses have been created to explain the underlying perturbations of adult trauma coagulopathy (i.e., tissue factor-related increase in thrombin generation, protein C activation, hypoperfusion, and hyperfibrinolysis), only a small number of studies have been performed to prove whether these mechanisms can likewise be detected in pediatric trauma patients. In addition, severe hypofibrinogenemia (<100 mg/dL) is a frequent finding in pediatric trauma patients (>20%). Although the probability of life-threatening coagulopathy is low with minor to moderate injury, it is present in almost all patients with an injury severity score >25, hypotension, hypothermia, and acidosis. As these multifactorial changes in hemostasis cannot be adequately and rapidly measured using standard laboratory testing, the use of viscoelastic measurements has been established in adult trauma management, but prospective studies in children are urgently needed. Apart from diagnostic challenges, several studies have focused on the impact of blood product ratios on the treatment of massively bleeding pediatric trauma patients. The majority of these studies were unable to show improved survival by using higher plasma to red blood cell ratios or higher platelet to red blood cells ratios, but there are no published randomized trials to definitively answer this question. A goal-directed transfusion protocol using viscoelastic tests together with early substitution with an antifibrinolytic and fibrinogen replacement is a promising alternative to traditional ratio-based interventions. Another crucial factor in treating trauma-induced coagulopathy is the early detection of hypofibrinogenemia, a common condition in massively transfused patients. Early treatment of hypofibrinogenemia is associated with improved morbidity and mortality in adults, but needs to be further studied in future pediatric trials. Pediatric trauma patients are not only threatened by coagulopathy-related bleeding but are also at higher risk for venous thromboembolism. Pediatric trauma patients with brain injury, central venous catheters, immobilization, or surgical procedures are at highest risk for developing a deep venous thrombosis. There are no specific pediatric guidelines established to prevent venous thromboembolism in children suffering from traumatic injury.

Ability of Fibrin Monomers to Predict Progressive Hemorrhagic Injury in Patients with Severe Traumatic Brain Injury

BACKGROUND

Progressive hemorrhagic injury (PHI) is common in patients with severe traumatic brain injury (TBI) and is associated with poor outcomes. TBI-associated coagulopathy is frequent and has been described as risk factor for PHI. This coagulopathy is a dynamic process involving hypercoagulable and hypocoagulable states either one after the other either concomitant. Fibrin monomers (FMs) are a direct marker of thrombin action and thus reflect coagulation activation. This study sought to determine the ability of FM to predict PHI after severe TBI.

METHODS

We conducted a prospective, observational study including all severe TBI patients admitted in the trauma center. Between September 2011 and September 2016, we enrolled patients with severe TBI into the derivation cohort. Between October 2016 and December 2018, we recruited the validation cohort on the same basis. Study protocol included FM measurements and standard coagulation test at admission and two computed tomography (CT) scans (upon arrival and at least 6 h thereafter). A PHI was defined by an increment in size of initial lesion (25% or more) or the development of a new hemorrhage in the follow-up CT scan. Multivariate logistic regression analysis was applied to identify predictors of PHI.

RESULTS

Overall, 106 patients were included in the derivation cohort. Fifty-four (50.9%) experienced PHI. FM values were higher in these patients (151 [136.8-151] vs. 120.5 [53.3-151], p < 0.0001). The ROC curve demonstrated that FM had a fair accuracy to predict the occurrence of PHI with an area under curve of 0.7 (95% CI [0.6-0.79]). The best threshold was determined at 131.7 μg/ml. In the validation cohort of 54 patients, this threshold had a negative predictive value of 94% (95% CI [71-100]) and a positive predictive value of 49% (95% CI [32-66]). The multivariate logistic regression analysis identified 2 parameters associated with PHI: FM ≥ 131.7 (OR 6.8; 95% CI [2.8-18.1]) and Marshall category (OR 1.7; 95% CI [1.3-2.2]). Coagulopathy was not associated with PHI (OR 1.3; 95% CI [0.5-3.0]). The proportion of patients with an unfavorable functional neurologic outcome at 6-months follow-up was higher in patients with positive FM: 59 (62.1%) versus 16 (29.1%), p < 0.0001.

CONCLUSIONS

FM levels at admission had a fair accuracy to predict PHI in patients with severe TBI. FM values ≥ 131.7 μg/ml are independently associated with the occurrence of PHI.