A retrospective study of the effect of fibrinogen levels during fresh frozen plasma transfusion in patients with traumatic brain injury

The significance of admission blood lactate and fibrinogen in pediatric traumatic brain injury: a single-center clinical study

BACKGROUND

Traumatic brain injury (TBI) is a significant cause of morbidity and mortality in pediatric patients, leading to long-term physical, cognitive, and psychological impairments. Blood lactate and fibrinogen levels have emerged as potential biomarkers associated with tissue hypoperfusion and coagulation dysfunction, respectively. However, limited research has specifically focused on the significance of these biomarkers in pediatric TBI. This study aimed to investigate the clinical significance of blood lactate and fibrinogen levels upon admission in pediatric patients with traumatic brain injury.

METHODS

The medical records of 80 children with a traumatic brain injury who were admitted from January 2017 to January 2021 were retrospectively analyzed. The two groups were compared according to whether the blood lactate in the admission arterial blood gas increased and the fibrinogen content in the coagulation function decreased. The clinical data of the children in the two groups were different, and then they were divided into a good prognosis group and a poor prognosis group according to the GOS prognostic score, and the differences in the clinical indicators of the two groups were compared.

RESULTS

Among the 80 patients, 33 had elevated blood lactate levels, 34 had decreased fibrinogen levels, and 29 had an unfavorable outcome (GOS < 4). Compared to the normal blood lactate group, there were no statistically significant differences in age, sex ratio, or platelet count in the elevated blood lactate group (P > 0.05). However, the elevated blood lactate group had lower Glasgow Coma Scale (GCS) scores upon admission, higher blood lactate levels, lower fibrinogen levels, longer hospital stay, lower GOS scores, and a higher proportion of GOS < 4 (P < 0.05). Compared to the normal fibrinogen group, there were no statistically significant differences in age, sex ratio, or platelet count in the decreased fibrinogen group (P > 0.05). However, the decreased fibrinogen group had lower GCS scores upon admission, higher blood lactate levels, lower fibrinogen levels, longer hospital stays, lower GOS scores, and a higher proportion of GOS < 4 (P < 0.05). Compared to the favorable outcome group, there were no statistically significant differences in age, sex ratio, or platelet count in the unfavorable outcome group (P > 0.05). However, the unfavorable outcome group had lower GCS scores upon admission, higher blood lactate levels, lower fibrinogen levels, longer hospital stays, a higher incidence of pulmonary infection, a higher incidence of stress ulcers, and lower GOS scores (P < 0.05).

CONCLUSION

The levels of blood lactate and fibrinogen may represent the severity of children with traumatic brain injury and may be risk factors for poor prognosis of children with traumatic brain injury.

Effect of low fibrinogen level on in-hospital mortality and 6-month functional outcome of TBI patients, a single center experience

In patients affected by traumatic brain injury (TBI), hypofibrinogenemia within the initial hours of trauma can be expected due to vascular and inflammatory changes. In this study, we aimed to evaluate the effect of hypofibrinogenemia on the in-hospital mortality and 6-month functional outcomes of TBI patients, admitted to Rajaee Hospital, a referral trauma center in Shiraz, Iran. This study included all TBI patients admitted to our center who had no prior history of coagulopathy or any systemic disease, were alive on arrival, and had not received any blood product before admission. On admission, hospitalization, imaging, and 6-month follow-up information of included patients were extracted from the TBI registry database. The baseline characteristics of patients with fibrinogen levels of less than 150 mg/dL were compared with the cases with higher levels. To assess the effect of low fibrinogen levels on in-hospital mortality, a uni- and multivariate was conducted between those who died in hospital and survivors. Based on the 6-month GOSE score of patients, those with GOSE < 4 (unfavorable outcome) were compared with those with a favorable outcome. A total of 3049 patients (84.3% male, 15.7% female), with a mean age of 39.25 ± 18.87, met the eligibility criteria of this study. 494 patients had fibrinogen levels < 150 mg/dl, who were mostly younger and had lower average GCS scores in comparison to cases with higher fibrinogen levels. By comparison of the patients who died during hospitalization and survivors, it was shown that fibrinogen < 150 mg/dl is among the prognostic factors for in-hospital mortality (OR:1.75, CI: 1.32:2.34, P-value < 0.001), while the comparison between patients with the favorable and unfavorable functional outcome at 6-month follow-up, was not in favor of prognostic effect of low fibrinogen level (OR: 0.80, CI: 0.58: 1.11, P-value: 0.19). Hypofibrinogenemia is associated with in-hospital mortality of TBI patients, along with known factors such as higher age and lower initial GCS score. However, it is not among the prognostic factors of midterm functional outcome.

The role of fibrinogen in traumatic brain injury: from molecular pathological mechanisms to clinical management

Fibrinogen is the substrate of plasma coagulation. It plays an important role in the formation of reticular network, which is crucial to the strength and stability of blood clots. In addition to directly participating in coagulation, fibrinogen also participates in the destruction of blood-brain barrier and neuroinflammation. This article reviews the pathophysiological changes of fibrinogen after traumatic brain injury. Considerable efforts have been made to understand the mechanisms by which fibrinogen damages the central nervous system. Combined with the latest research hotspots, potentially promising treatment strategies at the molecular level were discussed. We believe that understanding the role of fibrinogen-mediated damage in nerve and blood-brain barrier function will enable timely intervention in patients with nerve damage, and guide the development of novel targeted therapeutics.

Association of donor characteristics with coagulation factor levels in fresh frozen plasma

BACKGROUND

Coagulation factors are essential to maintain normal hemostasis. Plasma for transfusion can be obtained from whole blood donation or plasma apheresis. Plasma obtained from whole blood donation is termed as fresh frozen plasma (FFP). The quality of FFP can be influenced by several factors including donor variables (such as age, gender, diet, genetic profile), environmental factors, collection methods, processing methods, storage temperature, etc. This study was done to assess the association of donor characteristics such as donor age, blood group, and smoking with coagulation factor levels in FFP units.

MATERIALS AND METHODS

The screening of donors for collection of whole blood units was done as per the national guidelines. A total of 144 FFP units were assessed for coagulation factors. The FFP units were tested for prothrombin time (PT), activated partial thromboplastin time, fibrinogen, coagulation factor VIII, and coagulation factor IX (CF IX) on coagulation analyzer.

RESULTS

A total of 144 FFP units were tested for coagulation parameters. The value of PT was highest in units prepared from donors in more than 45 years of age group. The value of CF IX was significantly lower in O blood group as compared to non-O blood group. The value of fibrinogen was significantly higher in smokers as compared to nonsmokers.

CONCLUSION

The findings of the present study further add evidence to the fact that donor factors such as age, blood group, and smoking have an impact on coagulation factor levels in FFP units.

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.

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.

Detecting traumatic brain injury-induced coagulopathy: What we are testing and what we are not

ABSTRACT

Coagulopathy after traumatic brain injury (TBI) is common and has been closely associated with poor clinical outcomes for the affected patients. Traumatic brain injury-induced coagulopathy (TBI-IC) is consumptive in nature and evolves rapidly from an injury-induced hypercoagulable state. Traumatic brain injury-induced coagulopathy defined by laboratory tests is significantly more frequent than clinical coagulopathy, which often manifests as secondary, recurrent, or delayed intracranial or intracerebral hemorrhage. This disparity between laboratory and clinical coagulopathies has hindered progress in understanding the pathogenesis of TBI-IC and developing more accurate and predictive tests for this severe TBI complication. In this review, we discuss laboratory tests used in clinical and research studies to define TBI-IC, with specific emphasis on what the tests detect and what they do not. We also offer perspective on developing more accurate and predictive tests for this severe TBI complication.

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.

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.

Association of Thromboelastography with Progression of Hemorrhagic Injury in Children with Traumatic Brain Injury

INTRODUCTION

Progression of hemorrhagic injury (PHI) in children with traumatic brain injury portends poor outcomes. The association between thromboelastography (TEG), functional coagulation assays, and PHI is not well characterized in children.

METHODS

This was a retrospective cohort study of children presenting with PHI at a pediatric level I academic trauma center from 2015 to 2020. Inclusion criteria were as follows: age less than 18 years, intracranial hemorrhage on admission head computed tomography scan, and admission rapid TEG assay and conventional coagulation tests. PHI was defined by the following radiographic criteria: any expansion of or new intracranial hemorrhage on subsequent head computed tomography scan. Rapid TEG values included Activated Clotting Time (ACT), alpha angle, maximum amplitude, and lysis at 30 min. Wilcoxon rank-sum test was used to assess baseline differences between groups with PHI and without PHI, including laboratory assays. Univariate analysis was performed to examine the association between variables of interest and PHI. Patients were dichotomized on the basis of this cut point to generate a "low ACT" group and a "high ACT" group. These variables were included in a multivariable logistic regression model to determine independent association with traumatic brain injury progression.

RESULTS

In total, 219 patients met criteria for analysis. In this cohort, the median (interquartile range [IQR]) age = 6 (2-12) years, median (IQR) Injury Severity Score = 21 (11-27), 68% were boys, and 69% sustained blunt injury. The rate of PHI was 25% (54). Median (IQR) time to PHI was 1 (0-4) days. Children with PHI had a higher Injury Severity Score (p < 0.001), lower Glasgow Coma Scale (p < 0.001), greater incidence of shock (p = 0.04), and lower admission hemoglobin (p = 0.02) compared with those without PHI. Children with PHI had a higher International Normalized Ratio (INR) and longer TEG-ACT; other TEG values (alpha angle, maximum amplitude, and lysis at 30 min) were not associated with PHI. In the logistic regression model accounting for other covariates associated with PHI, elevated ACT remained an independent predictor of progression (odds ratio = 2.25, 95% confidence interval 1.09-4.66; p = 0.03; area under the receiver operating characteristic curve = 0.76). After adjusting for confounders, INR fell out of the model and was not an independent predictor of progression (odds ratio = 1.32, 95% confidence interval 0.60-2.93; p = 0.49).

CONCLUSIONS

Although INR was elevated in children with PHI and has been associated with poor clinical outcomes, only admission TEG-ACT was independently associated with PHI. Further study is warranted to determine whether TEG-ACT reflects an actionable therapeutic target.

Multiple Machine Learning Approaches Based on Postoperative Prediction of Pulmonary Complications in Patients With Emergency Cerebral Hemorrhage Surgery

Objective

This study aimed to create a prediction model of postoperative pulmonary complications for the patients with emergency cerebral hemorrhage surgery.

Methods

Patients with hemorrhage surgery who underwent cerebral hemorrhage surgery were included and divided into two groups: patients with or without pulmonary complications. Patient characteristics, previous history, laboratory tests, and interventions were collected. Univariate and multivariate logistic regressions were used to predict postoperative pulmonary infection. Multiple machine learning approaches have been used to compare their importance in predicting factors, namely K-nearest neighbor (KNN), stochastic gradient descent (SGD), support vector classification (SVC), random forest (RF), and logistics regression (LR), as they are the most successful and widely used models for clinical data.

Results

Three hundred and fifty four patients with emergency cerebral hemorrhage surgery between January 1, 2017 and December 31, 2020 were included in the study. 53.7% (190/354) of the patients developed postoperative pulmonary complications (PPC). Stepwise logistic regression analysis revealed four independent predictive factors associated with pulmonary complications, including current smoker, lymphocyte count, clotting time, and ASA score. In addition, the RF model had an ideal predictive performance.

Conclusions

According to our result, current smoker, lymphocyte count, clotting time, and ASA score were independent risks of pulmonary complications. Machine learning approaches can also provide more evidence in the prediction of pulmonary complications.

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.

Analysis of changes in the volume of edema around brain contusions and the influencing factors: A single-center, retrospective, observational study

Traumatic brain injury (TBI), a common neurosurgical condition, has well-known treatment guidelines. However, the mechanisms underlying the varying severity of brain edema secondary to TBI are largely unknown, leading to controversial treatments.This study seeks to measure edema volumes around brain contusions in different regions, analyze factors related to differences in edema volume and provide a theoretical basis for brain edema treatment.Data from 113 brain contusion patients treated at the Department of Neurosurgery of Fuzhou General Hospital from January 2017 to November 2019 were analyzed retrospectively. Based on computed tomography (CT) data, the patients were divided into the venous group (brain contusion in regions with large cortical veins, n = 47) and the nonvenous group (brain contusions in other regions, n = 66). Here, 3D Slicer software was used to calculate the brain contusion volume on the first CT obtained after injury and the brain contusion volume and its surrounding edema on the 5th day after injury. The brain contusion volume to surrounding edema volume ratio was calculated, and the number of patients who showed brain contusion progression requiring surgery was determined. Hematocrit (Hct), fibrinogen (Fg), and d-dimer levels within 6 hours and on the 5th day after admission were also compared.Patients in the venous group had a significantly increased percentage of area with edema around the brain contusion compared with patients in the nonvenous group (P < .05), and the 2 groups showed no significant difference in the number of patients with brain contusion progression or surgical treatment (P > .05) or Hct, Fg, or d-dimer (D-D) levels. For all patients, Hct, Fg, and D-D levels within 6 hours after admission were significantly different from those on the 5th day (P < .05 for all).Cortical venous obstruction may be the most important factor influencing edema around brain contusions. The Fg level decreased slightly, and the D-D level increased to its peak rapidly after mild-moderate TBI. This change was followed by a gradual increase in the former and a gradual decrease in the latter.

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.

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.

Thromboelastography is a Marker for Clinically Significant Progressive Hemorrhagic Injury in Severe Traumatic Brain Injury

BACKGROUND

Coagulopathy in traumatic brain injury (TBI) is associated with increased risk of poor outcomes, but accurate prediction of clinically significant progressive hemorrhagic injury (PHI) in patients with severe TBI remains a challenge. Thromboelastography (TEG) is a real-time test of whole blood coagulation that provides dynamic information about global hemostasis. This study aimed to identify differences in TEG values between patients with severe TBI who did or did not experience clinically significant PHI.

METHODS

This was a single-center retrospective cohort study of adult patients with severe TBI. Patients were eligible for inclusion if initial Glasgow coma scale (GCS) was ≤ 8 and baseline head computed tomography (CT) imaging and TEG were available. Exclusion criteria included receipt of hemostatic agents prior to TEG. PHI was defined as bleeding expansion on CT within 24 h associated with 2-point drop in GCS, neurosurgical intervention, or mortality within 24 h. The primary endpoint was TEG value differences between patients with and without PHI. Secondary endpoints included differences in conventional coagulation tests (CCTs) between groups.

RESULTS

Of the 526 patients evaluated, 141 met inclusion criteria. The most common reason for exclusion was lack of baseline TEG and receipt of reversal product prior to TEG. Sixty-four patients experienced PHI in the first 24 h after presentation. K time (2.03 min vs. 1.33 min, P = 0.035) and alpha angle (65° vs. 69°, P = 0.015) were found to be significantly different in patients experiencing PHI. R time (5.25 min vs. 4.71 min), maximum amplitude (61 mm vs. 63 mm), and clot lysis at 30 min after maximum clot strength (3.5% vs. 1.7%) were not significantly different between groups. Of the CCTs, only activated partial thromboplastin time (30.3 s vs. 27.6 s, P = 0.014) was found to be different in patients with PHI.

CONCLUSIONS

Prolonged K time and narrower alpha angle were found to be associated with developing clinically significant PHI in patients with severe TBI. Despite differences detected in alpha angle, median values in both groups were within normal reference ranges. These abnormalities may reflect pathologic hypoactivity of fibrinogen, and further study is warranted to evaluate TEG-guided cryoprecipitate administration in this patient population.

Random Forest-Based Prediction of Outcome and Mortality in Patients with Traumatic Brain Injury Undergoing Primary Decompressive Craniectomy

BACKGROUND

Various prognostic models are used to predict mortality and functional outcome in patients after traumatic brain injury with a trend to incorporate machine learning protocols. None of these models is focused exactly on the subgroup of patients indicated for decompressive craniectomy. Evidence regarding efficiency of this surgery is still incomplete, especially in patients undergoing primary decompressive craniectomy with evacuation of traumatic mass lesions.

METHODS

In a prospective study with a 6-month follow-up period, we assessed postoperative outcome and mortality of 40 patients who underwent primary decompressive craniectomy for traumatic brain injuries during 2018-2019. The results were analyzed in relation to a wide spectrum of preoperatively available demographic, clinical, radiographic, and laboratory data. Random forest algorithms were trained for prediction of both mortality and unfavorable outcome, with their accuracy quantified by area under the receiver operating curves (AUCs) for out-of-bag samples.

RESULTS

At the end of the follow-up period, we observed mortality of 57.5%. Favorable outcome (Glasgow Outcome Scale [GOS] score 4-5) was achieved by 30% of our patients. Random forest-based prediction models constructed for 6-month mortality and outcome reached a moderate predictive ability, with AUC = 0.811 and AUC = 0.873, respectively. Random forest models trained on handpicked variables showed slightly decreased AUC = 0.787 for 6-month mortality and AUC = 0.846 for 6-month outcome and increased out-of-bag error rates.

CONCLUSIONS

Random forest algorithms show promising results in prediction of postoperative outcome and mortality in patients undergoing primary decompressive craniectomy. The best performance was achieved by Classification Random forest for 6-month outcome.

Links between thrombosis and inflammation in traumatic brain injury

Traumatic brain injury (TBI) continues to be a major healthcare problem and there is much to be explored regarding the secondary pathobiology to identify early predictive markers and new therapeutic targets. While documented changes in thrombosis and inflammation in major trauma have been well described, growing evidence suggests that isolated TBI also results in systemic alterations in these mechanisms. Here, we review recent experimental and clinical findings that demonstrate how blood-brain barrier dysfunction, systemic immune response, inflammation, platelet activation, and thrombosis contribute significantly to the pathogenesis of TBI. Despite advances in the links between thrombosis and inflammation, there is a lack of treatment options aimed at both processes and this could be crucial to treating vascular injury, local and systemic inflammation, and secondary ischemic events following TBI. With emerging evidence of newly-identified roles for platelets, leukocytes, the coagulation system and extracellular vesicles in processes of inflammation and thrombosis, there is a growing need to characterize these mechanisms within the context of TBI and whether these changes persist into the chronic phase of injury. Importantly, this review defines areas in need of further research to advance the field and presents a roadmap to identify new diagnostic and treatment options for TBI.

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.