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

Global neurotrauma: A systematic review and summary of the current state of registries around the world

Neurotrauma registries (NTR) collect data on traumatic brain injuries (TBI) to advance knowledge, shape policies, and improve outcomes. This study reviews global NTRs from High-Income (HICs) and Low- and Middle-Income countries (LMICs). A systematic review was conducted using PubMed, Google Scholar, Embase, and Web of Science following PRISMA guidelines to identify relevant NTRs. Twenty-six articles were included, revealing ten different NTRs from Europe, North America, Latin America, the Middle East, and Asia. North America had the most registries at four, followed by Europe and Asia with two each, and Latin America and the Middle East with one each. The median database size was 1,734 patients (Range: 65-25,000), with the largest registry from the United States (FITBIR DB) and the smallest from Iran (NSCIR-IR). The longest data collection period was 32 years, with a mean age of 43.1 years (Range: 9.07-60.0). Males comprised 70 % of patients. Sixty-six percent of articles emphasized outcomes such as functionality, length of stay, and mortality. Key challenges identified included issues with missing data and incomplete records (n = 4), lack of standardization in data collection procedures (n = 3), staffing shortages (n = 5), lack of IT infrastructure (n = 3), and problems with reproducibility, particularly in high-income countries (n = 4). Our review highlights the need for a large-scale global NTR, addressing LMIC barriers through private-public partnerships with organized neurosurgery members.

High Fresh Frozen Plasma to Red Blood Cell Ratio and Survival Outcomes in Blunt Trauma

Importance

Current trauma-care protocols advocate early administration of fresh frozen plasma (FFP) in a ratio close to 1:1 with red blood cells (RBCs) to manage trauma-induced coagulopathy in patients with severe blunt trauma. However, the benefits of a higher FFP to RBC ratio have not yet been established.

Objective

To investigate the effectiveness of a high FFP to RBC transfusion ratio in the treatment of severe blunt trauma and explore the nonlinear relationship between the ratio of blood products used and patient outcomes.

Design, Setting, and Participants

This was a multicenter cohort study retrospectively analyzing data from the Japan Trauma Data Bank, including adult patients with severe blunt trauma without severe head injury (Injury Severity Score ≥16 and head Abbreviated Injury Scale <3) between 2019 and 2022.

Exposures

Patients were categorized into 2 groups based on the ratio of FFP to RBC: the high-FFP group (ratio >1) and the low-FFP group (ratio ≤1).

Main Outcomes and Measures

All-cause in-hospital mortality was the primary outcome. Additionally, the occurrence of transfusion-related adverse events was evaluated.

Results

Among the 1954 patients (median [IQR] age, 61 [41-77] years; 1243 male [63.6%]) analyzed, 976 (49.9%) had a high FFP to RBC ratio. Results from logistic regression, weighted by inverse probability treatment weighting, demonstrated an association between the group with a high-FFP ratio and lower in-hospital mortality (odds ratio, 0.73; 95% CI, 0.56-0.93) compared with a low-FFP ratio. Nonlinear trends were noted, suggesting a potential ceiling effect on transfusion benefits.

Conclusions and Relevance

In this cohort study, a high FFP to RBC ratio was associated with favorable survival in patients with severe blunt trauma. These outcomes highlight the importance of revising the current transfusion protocols to incorporate a high FFP to RBC ratio, warranting further research on optimal patient treatment.

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.

The Examination of Prognostic Factors and Treatment Strategies for Traumatic Cerebrospinal Fluid Leakage

Introduction This study aimed to determine the optimal timing for surgical intervention and the prognostic factors of cerebrospinal fluid (CSF) leakage. Methods We identified 25 patients with probable CSF leaks from 472 consecutive patients with head trauma. In addition to baseline characteristics and findings on admission, injury severity score (ISS), abbreviated injury score (AIS), and other factors related to CSF leakage were considered. We analyzed the prognostic factors after setting the primary endpoint as the modified Rankin Scale (mRS) at the time of discharge to determine the appropriate timing for surgical intervention. Results Univariate analysis revealed significantly poorer prognoses for elderly patients (p<0.001) and cases with low Glasgow Coma Scale (GCS) levels (p=0.039) and high D-dimer levels (p=0.028), which was consistent with findings from the analyses of all patients with head trauma. We found that multiple traumas (AIS≥3 at two or more sites, p=0.047) and high lactate levels (p=0.043) were poor prognostic factors specific to CSF leakage cases, while a longer time to CSF leakage cessation was also associated with a poorer prognosis (median, six days versus 13 days, p=0.014). An evaluation of the time to closure found that spontaneous cessation occurred within 14 days in most cases. Conclusions Conservative medical treatment is the first choice for most cases of traumatic CSF leakage. Surgical intervention should be considered if leakage does not cease after 14 days post injury. Furthermore, severe multiple injuries and high lactate levels were poor prognostic factors specific to patients with CSF leakage.

Plasma D-dimer levels are a biomarker for in-hospital complications and long-term mortality in patients with traumatic brain injury

Introduction

Traumatic brain injury (TBI) is a major health concern worldwide. D-dimer levels, commonly used in the diagnosis and treatment of neurological diseases, may be associated with adverse events in patients with TBI. However, the relationship between D-dimer levels, TBI-related in-hospital complications, and long-term mortality in patients with TBI has not been investigated. Here, examined whether elevated D-dimer levels facilitate the prediction of in-hospital complications and mortality in patients with TBI.

Methods

Overall, 1,338 patients with TBI admitted to our institute between January 2016 and June 2022 were retrospectively examined. D-dimer levels were assessed within 24 h of admission, and propensity score matching was used to adjust for baseline characteristics.

Results

Among the in-hospital complications, high D-dimer levels were associated with electrolyte metabolism disorders, pulmonary infections, and intensive care unit admission (p < 0.05). Compared with patients with low (0.00-1.54 mg/L) D-dimer levels, the odds of long-term mortality were significantly higher in all other patients, including those with D-dimer levels between 1.55 mg/L and 6.35 mg/L (adjusted hazard ratio [aHR] 1.655, 95% CI 0.9632.843), 6.36 mg/L and 19.99 mg/L (aHR 2.38, 95% CI 1.416-4.000), and >20 mg/L (aHR 3.635, 95% CI 2.195-6.018; p < 0.001). D-dimer levels were positively correlated with the risk of death when the D-dimer level reached 6.82 mg/L.

Conclusion

Overall, elevated D-dimer levels at admission were associated with adverse outcomes and may predict poor prognosis in patients with TBI. Our findings will aid in the acute diagnosis, classification, and management of TBI.

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.

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.