Defibrination after brain-tissue destruction: A serious complication of head injury

Coagulopathy in Penetrating Ballistic Cranial Trauma: A 7-Year Experience

BACKGROUND AND OBJECTIVES

Penetrating ballistic cranial trauma (PBCT) carries significant mortality when compared with blunt trauma. The development of coagulopathy in PBCT is a strong predictor of mortality. The goal of the study was to describe the incidence and risk factors of coagulopathy in PBCT and to report the value of tranexamic acid administration in PBCT.

METHODS

We retrospectively analyzed 270 patients who presented with PBCT to a single, Level 1 trauma center between 2016 and 2023.

RESULTS

A total of 47% (127/270) of patients with PBCT developed coagulopathy at presentation. Fifty-seven patients received tranexamic acid at presentation, which did not affect the development of coagulopathy. Coagulopathic patients were more likely to have more serious injury patterns (bihemispheric [adjusted odds ratio, aOR: 2.6 CI: 1.4-4.9, P = .004] or transventricular trajectories [aOR: 4.9 CI: 1.9-19.6, P = .03]). In addition, they presented with a larger base deficit (aOR: 0.9 CI: 1.002-1.2 per mEq/L, P = .006) which negatively correlated with the international normalized ratio (ρ: -0.46, P < .0001, Spearman correlation). Using thromboelastography helped to identify an additional 20% of patients who presented with normal coagulation on conventional testing.

CONCLUSION

Coagulopathy is prevalent in approximately 50% of patients with PBCT and is persistent despite treatment in a substantial subset of patients. The addition of thromboelastography with its increased coagulopathy sensitivity can potentially guide treatment more efficiently than traditional coagulopathy laboratory tests and fibrinogen alone. Patients with a significant base deficit on arterial blood gas are at higher risk for coagulopathy.

Concomitant severe traumatic brain injury is not associated with increased red blood cell transfusion volumes in patients with pelvic fractures: A retrospective observational study

INTRODUCTION

Traumatic brain injury (TBI)-associated coagulopathy significantly influences survival outcomes in patients with multiple injuries. Severe TBI can potentially affect systemic hemostasis due to coagulopathy; however, there is limited evidence regarding whether the risk of hemorrhage increases in patients with pelvic fractures complicated with TBI. Therefore, through multivariable analysis, we aimed to examine the association between severe TBI and increased blood transfusion requirements in patients with pelvic fractures.

MATERIALS AND METHODS

This retrospective observational study was conducted at a tertiary care facility in Japan. Patients aged 16 years or older with pelvic fractures who were admitted to our intensive care unit between April 2014 and December 2021 were included in the analysis. The patients were categorized into no to mild and severe TBI groups according to whether the Head Abbreviated Injury Scale (AIS) score was 3 or higher. The primary outcome was the number of red blood cell (RBC) units transfused within 24 h after arrival at the hospital. The primary outcome was analyzed using univariable and multivariable linear regression analyses. The covariates used for the multivariable linear regression analysis were age, sex, antithrombotic therapy, mechanism of injury, Pelvic AIS score, and extravasation on contrast-enhanced computed tomography on admission.

RESULTS

We identified 315 eligible patients (221 and 94 in the no to mild and severe TBI groups, respectively). In the univariable analysis, the RBC transfusion volume within 24 h after arrival was significantly higher in the severe TBI group than in the no to mild TBI group (2.53-unit increase; 95 % confidence interval [CI]: 0.46-4.61). However, in the multivariable analysis, no statistically significant association was detected between severe TBI and the RBC transfusion volume within 24 h after arrival at the hospital (0.87-unit increase; 95 % CI: -1.11-2.85).

CONCLUSIONS

Concomitant severe TBI was not associated with increased RBC transfusion volumes in patients with pelvic fractures on multivariable analysis.

Cerebral infarction following administration of andexanet alfa for anticoagulant reversal in a patient with traumatic acute subdural hematoma

Background

Anticoagulants prevent thrombosis in patients with atrial fibrillation (AF) and venous thromboembolism but increase the risk of hemorrhagic complications. If severe bleeding occurs with anticoagulant use, discontinuation and rapid reversal are essential. However, the optimal timing for resuming anticoagulants after using reversal agents remains unclear. Here, we report early cerebral infarction following the use of andexanet alfa (AA), a specific reversal agent for factor Xa inhibitors, in a patient with traumatic acute subdural hematoma (ASDH). The possible causes of thromboembolic complication and the optimal timing for anticoagulant resumption are discussed.

Case Description

An 84-year-old woman receiving rivaroxaban for AF presented with impaired consciousness after a head injury. Computed tomography (CT) revealed right ASDH. The patient was administered AA and underwent craniotomy. Although the hematoma was entirely removed, she developed multiple cerebral infarctions 10 h after the surgery. These infarctions were considered cardiogenic cerebral embolisms and rivaroxaban was therefore resumed on the same day. This case indicates the possibility of early cerebral infarction after using a specific reversal agent for factor Xa inhibitors.

Conclusion

Most studies suggest that the safest time for resuming anticoagulants after using reversal agents is between 7 and 12 days. The present case showed that embolic complications may develop much earlier than expected. Early readministration of anticoagulant may allow for adequate prevention of the acute thrombotic syndromes.

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.

TRAUMATIC BRAIN INJURY PROVOKES LOW FIBRINOLYTIC ACTIVITY IN SEVERELY INJURED PATIENTS

BACKGROUND

Traumatic brain injury (TBI) in combination with shock has been associated with hypocoagulability. However, recent data suggest that TBI itself can promote a systemic procoagulant state via the release of brain-derived extracellular vesicles. The objective of our study was to identify if TBI was associated with differences in thrombelastography (TEG) indices when controlling for other variables associated with coagulopathy following trauma. We hypothesized that TBI is independently associated with a less coagulopathic state.

METHODS

Prospective study including all highest-level trauma activations at an urban level 1 trauma center, from 2014-2020. TBI was defined as AIS Head ≥3. Blood samples were drawn at ED admission. Linear regression was used to assess the role of independent predictors on TIC. Models adjusted for ISS, shock (defined as ED SBP < 70, or ED SBP < 90 and ED HR > 108, or first hospital base deficit ≥10), and prehospital GCS.

RESULTS

Of the 1,023 patients included, 291 (28%) suffered a TBI. TBI patients more often were female (26% vs. 19%, p = 0.01), had blunt trauma (83% vs. 43%, p < 0.0001), shock (33% vs. 25%, p = 0.009), and higher median ISS (29 vs. 10, p < 0.0001). Fibrinolysis shutdown (25% vs. 18%) was more common in the TBI group (p < 0.0001). When controlled for the confounding effects of ISS and shock, the presence of TBI independently decreases LY30 (Beta estimate: - 0.16 ± 0.06, p = 0.004). This effect of TBI on LY30 persisted when controlling for sex and mechanism of injury in addition to ISS and shock (Beta estimate: -0.13 ± 0.06, p = 0.022).

CONCLUSIONS

TBI is associated with lower LY30 independent of shock, tissue injury, sex, and mechanism of injury. These findings suggest a propensity toward a less coagulopathic state in patients with TBI, possibly due to fibrinolysis shutdown. Tranexamic acid has been reported to improve outcomes following TBI. Our data suggest the mechanism may be independent of changes in fibrinolysis.

LEVEL OF EVIDENCE

Level III, Prognostic and Epidemiological.

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.

Platelet-like particles reduce coagulopathy-related and neuroinflammatory pathologies post-experimental traumatic brain injury

Coagulopathy may occur following traumatic brain injury (TBI), thereby negatively affecting patient outcomes. Here, we investigate the use of platelet-like particles (PLPs), poly(N-isopropylacrylamide-co-acrylic-acid) microgels conjugated with a fibrin-specific antibody, to improve hemostasis post-TBI. The objective of this study was to diminish coagulopathy in a mouse TBI model (controlled cortical impact) via PLP treatment, and subsequently decrease blood-brain barrier (BBB) permeability and neuroinflammation. Following an acute intravenous injection of PLPs post-TBI, we analyzed BBB permeability, ex vivo coagulation parameters, and neuroinflammation at 24 hr and 7 days post-TBI. Both PLP-treatment and control particle-treatment had significantly decreased BBB permeability and improved clot structure 24 hr post-injury. Additionally, no significant change in tissue sparing was observed between 24 hr and 7 days for PLP-treated cohorts compared to that observed in untreated cohorts. Only PLP-treatment resulted in significant reduction of astrocyte expression at 7 days and percent difference from 24 hr to 7 days. Finally, PLP-treatment significantly reduced the percent difference from 24 hr to 7 days in microglia/macrophage density compared to the untreated control. These results suggest that PLP-treatment addressed acute hypocoagulation and decreased BBB permeability followed by decreased neuroinflammation and fold-change tissue loss by 7 days post-injury. These promising results indicate that PLPs could be a potential therapeutic modality for TBI.

Fibrinolytic Activation in Patients with Progressive Intracranial Hemorrhage after Traumatic Brain Injury

Progression of intracranial hemorrhage (PICH) is a significant cause of secondary brain injury in patients with traumatic brain injury (TBI). Previous studies have implicated a variety of mediators that contribute to PICH. We hypothesized that patients with PICH would display either a hypocoagulable state, hyperfibrinolysis, or both. We conducted a prospective study of adult trauma patients with isolated TBI. Blood was obtained for routine coagulation assays, platelet count, fibrinogen, thrombelastography, markers of thrombin generation, and markers of fibrinolysis at admission and 6, 12, 24, and 48 h. Univariate analyses were performed to compare baseline characteristics between groups. Linear regression models were created, adjusting for baseline differences, to determine the relationship between individual assays and PICH. One hundred forty-one patients met entry criteria, of whom 71 had hemorrhage progression. Patients with PICH had a higher Injury Severity Score and Abbreviated Injury Scale score (head), a lower Glasgow Coma Scale score, and lower plasma sodium on admission. Patients with PICH had higher D-dimers on admission. After adjusting for baseline differences, elevated D-dimers remained significantly associated with PICH compared to patients without PICH at admission. Hypocoagulation was not significantly associated with PICH in these patients. The association between PICH and elevated D-dimers early after injury suggests that fibrinolytic activation may contribute to PICH in patients with TBI.

Platelet Dysfunction after Traumatic Brain Injury: A Review

Coagulopathy is a known sequela of traumatic brain injury (TBI) and can lead to increased morbidity and mortality. Platelet dysfunction has been identified as one of several etiologies of coagulopathy following TBI and has been associated with poor outcomes. Regardless of whether the platelet dysfunction occurs as a direct consequence of the injury or because of pre-existing medical comorbidities or medication use, accurate detection and monitoring of response to therapy is key to optimal patient care. Platelet transfusion has been proposed as a potential therapeutic intervention to treat platelet dysfunction, with several studies using platelet function assays to monitor response. The development of increasingly precise diagnostic testing is providing enhanced understanding of the specific derangement in the hemostatic process, allowing clinicians to provide patient-specific treatment plans. There is wide variability in the currently available literature on the incidence and clinical significance of platelet dysfunction following TBI, which creates challenges with developing evidence-based management guidelines. The relatively high prevalence of platelet inhibitor therapy serves as an additional confounding factor. In addition, the data are largely retrospective in nature. We performed a literature review to provide clarity on this clinical issue. We reviewed 348 abstracts, and included 97 manuscripts in our final literature review. Based on the currently available research, platelet dysfunction has been consistently demonstrated in patients with moderate-severe TBI. We recommend the use of platelet functional assays to evaluate patients with TBI. Platelet transfusion directed at platelet dysfunction may lead to improved clinical outcome. A randomized trial guided by implementation science could improve the applicability of these practices.

Microvascular thrombosis: experimental and clinical implications

A significant amount of clinical and research interest in thrombosis is focused on large vessels (eg, stroke, myocardial infarction, deep venous thrombosis, etc.); however, thrombosis is often present in the microcirculation in a variety of significant human diseases, such as disseminated intravascular coagulation, thrombotic microangiopathy, sickle cell disease, and others. Further, microvascular thrombosis has recently been demonstrated in patients with COVID-19, and has been proposed to mediate the pathogenesis of organ injury in this disease. In many of these conditions, microvascular thrombosis is accompanied by inflammation, an association referred to as thromboinflammation. In this review, we discuss endogenous regulatory mechanisms that prevent thrombosis in the microcirculation, experimental approaches to induce microvascular thrombi, and clinical conditions associated with microvascular thrombosis. A greater understanding of the links between inflammation and thrombosis in the microcirculation is anticipated to provide optimal therapeutic targets for patients with diseases accompanied by microvascular thrombosis.

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.

Incidence of Antithrombin Deficiency and Anti-Cardiolipin Antibodies After Severe Traumatic Brain Injury: A Prospective Cohort Study

BACKGROUND

Animal studies suggested that cerebral mitochondrial cardiolipin phospholipids were released after severe traumatic brain injury (TBI), contributing to the pathogenesis of thromboembolism.

OBJECTIVES

To determine the incidence of anti-cardiolipin antibodies after severe TBI and whether this was related to the severity of TBI and development of venous thromboembolism.

METHODS

Serial anti-cardiolipin antibodies, antithrombin levels, viscoelastic testing, and coagulation parameters were measured on admission, day-1, and between day-5 and day-7 in patients with severe TBI requiring intracranial pressure monitoring.

RESULTS

Of the 40 patients included (85% male and median age 42 years), 7 (18%) had a raised Ig-G or Ig-M anti-cardiolipin antibody titer after TBI. Antithrombin levels were below the normal level-especially on day-0 and day-1-in 15 patients (38%), and 14 patients (38%) developed an increase in maximum clot firmness on the viscoelastic test in conjunction with elevations in fibrinogen concentration and platelet count. Four patients (10%) developed deep vein thrombosis, and 10 patients (25%) died, both of which were not significantly related to the presence of anti-cardiolipin antibodies (P = 0.619 and P = 0.638, respectively).

CONCLUSIONS

A reduction in antithrombin level and development of anti-cardiolipin antibodies were not rare immediately after severe TBI; these abnormalities were followed by an increase in in vitro clot strength due to elevations in fibrinogen concentration and platelet count. The quantitative relationships between the development of anti-cardiolipin antibodies and severity of TBI or clinical thromboembolic events deserve further investigation.

Severe traumatic brain injury is associated with a unique coagulopathy phenotype

BACKGROUND

Traumatic brain injury (TBI) patients present on a spectrum from hypocoagulability to hypercoagulability, depending on the injury complexity, severity, and time since injury. Prior studies have found a unique coagulopathy associated with TBI using conventional coagulation assays such as INR; however, few studies have assessed the association of TBI and coagulopathy using viscoelastic assays that comprehensively evaluate the coagulation in whole blood. This study aims to reevaluate the TBI-specific trauma-induced coagulopathy using arrival thrombelastography. Because brain tissue is high in key procoagulant molecules, we hypothesize that isolated TBI is associated with procoagulant and hypofibrinolytic profiles compared with injuries of the torso, extremities, and polytrauma, including TBI.

METHODS

Data are from the prospective Trauma Activation Protocol study. Activated clotting time (ACT), angle, maximum amplitude (MA), 30-minute percent lysis after MA (LY30), and functional fibrinogen levels (FFLEV) were recorded. Patients were categorized into isolated severe TBI (I-TBI), severe TBI with torso and extremity injuries (TBI + TORSO/EXTREMITIES), and isolated torso and extremity injuries (I-TORSO/EXTREMITIES). Poisson regression was used to adjust for multiple confounders.

RESULTS

Overall, 572 patients (48 I-TBI, 45 TBI + TORSO/EXTREMITIES, 479 I-TORSO/EXTREMITIES) were included in this analysis. The groups differed in INR, ACT, angle, MA, and FFLEV but not in 30-minute percent lysis. When compared with I-Torso/Extremities, after adjustment for confounders, severe I-TBI was independently associated with ACT less than 128 seconds (relative risk [RR], 1.5; 95% confidence interval [CI], 1.1-2.2), angle less than 65 degrees (RR, 2.2; 95% CI, 1.4-3.6), FFLEV less than 356 (RR, 1.7; 95% CI, 1.2-2.4) but not MA less than 55 mm, hyperfibrinolysis, fibrinolysis shutdown, or partial thromboplastin time (PTT) greater than 30.

CONCLUSION

Severe I-TBI was independently associated with a distinct coagulopathy with delayed clot formation but did not appear to be associated with fibrinolysis abnormalities. Low fibrinogen and longer ACT values associated with I-TBI suggest that early coagulation factor replacement may be indicated in I-TBI patients over empiric antifibrinolytic therapy. Mechanisms triggering coagulopathy in TBI are unique and warrant further investigation.

LEVEL OF EVIDENCE

Retrospective cohort study, prognostic, level III.

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.

Management of moderate and severe traumatic brain injury

Traumatic brain injury (TBI) is a common disorder with high morbidity and mortality, accounting for one in every three deaths due to injury. Older adults are especially vulnerable. They have the highest rates of TBI-related hospitalization and death. There are about 2.5 to 6.5 million US citizens living with TBI-related disabilities. The cost of care is very high. Aside from prevention, little can be done for the initial primary injury of neurotrauma. The tissue damage incurred directly from the inciting event, for example, a blow to the head or bullet penetration, is largely complete by the time medical care can be instituted. However, this event will give rise to secondary injury, which consists of a cascade of changes on a cellular and molecular level, including cellular swelling, loss of membrane gradients, influx of immune and inflammatory mediators, excitotoxic transmitter release, and changes in calcium dynamics. Clinicians can intercede with interventions to improve outcome in the mitigating secondary injury. The fundamental concepts in critical care management of moderate and severe TBI focus on alleviating intracranial pressure and avoiding hypotension and hypoxia. In addition to these important considerations, mechanical ventilation, appropriate transfusion of blood products, management of paroxysmal sympathetic hyperactivity, using nutrition as a therapy, and, of course, venous thromboembolism and seizure prevention are all essential in the management of moderate to severe TBI patients. These concepts will be reviewed using the recent 2016 Brain Trauma Foundation Guidelines to discuss best practices and identify future research priorities.

Probability of Soluble Tissue Factor Release Lead to the Elevation of D-dimer as a Biomarker for Traumatic Brain Injury

D-dimer is a potential biomarker for the detection of traumatic brain injury (TBI). However, the mechanisms that trigger elevation of D-dimer in TBI remain unclear. The purpose of this study was to evaluate the reliability of D-dimer in blood as a biomarker for TBI and to determine the mechanisms involved in regulating its blood levels. Nine patients with moderate to severe isolated TBI (Glasgow Coma Scale [GCS] score 7–13) were admitted to our hospital from May 2013 to June 2014. Blood samples were collected from systemic arteries on arrival and at 1, 3, 5, and 7 days after injury. Blood levels of neuron specific enolase (NSE), D-dimer, and soluble tissue factor (sTF) were measured. NSE (33.4 ng/ml: normal <12.0 ng/ml) and D-dimer (56.1 μg/ml: normal <1.0 μg/ml) were elevated at admission and declined on day 1 after injury. At admission, there were significant correlations of D-dimer levels with NSE (R = 0.727, P = 0.026) and sTF (R = 0.803, P = 0.009) levels. The blood level of D-dimer accurately reflects the degree of brain tissue damage indicated by NSE levels. Our data suggest that release of sTF induced by brain tissue damage may activate the coagulation cascade, leading to elevation of D-dimer.

Sympathoadrenal Activation is Associated with Acute Traumatic Coagulopathy and Endotheliopathy in Isolated Brain Injury

Background:

Acute coagulopathy after traumatic brain injury (TBI) involves a complex multifactorial hemostatic response that is poorly characterized. Objectives: To examine early posttraumatic alterations in coagulofibrinolytic, endothelial, and inflammatory blood biomarkers in relation to sympathetic nervous system (SNS) activation and 6-month patient outcomes, using multivariate partial least-squares (PLS) analysis.

Patients and Methods:

A multicenter observational study of 159 adult isolated TBI patients admitted to the emergency department at an urban level I trauma center, was performed. Plasma concentrations of 6 coagulofibrinolytic, 10 vascular endothelial, 19 inflammatory, and 2 catecholamine biomarkers were measured by immunoassay on admission and 24 h postinjury. Neurological outcome at 6 months was assessed using the Extended Glasgow Outcome Scale. PLS-discriminant analysis was used to identify salient biomarker contributions to unfavorable outcome, whereas PLS regression analysis was used to evaluate the covariance between SNS correlates (catecholamines) and biomarkers of coagulopathy, endotheliopathy, and inflammation.

Results:

Biomarker profiles in patients with an unfavorable outcome displayed procoagulation, hyperfibrinolysis, glycocalyx and endothelial damage, vasculature activation, and inflammation. A strong covariant relationship was evident between catecholamines and biomarkers of coagulopathy, endotheliopathy, and inflammation at both admission and 24 h postinjury.

Conclusions:

Biomarkers of coagulopathy and endotheliopathy are associated with poor outcome after TBI. Catecholamine levels were highly correlated with endotheliopathy and coagulopathy markers within the first 24 h after injury. Further research is warranted to characterize the pathogenic role of SNS-mediated hemostatic alterations in isolated TBI.

Comparative Study of Derangement of Coagulation Profile between Adult and Pediatric Population in Moderate to Severe Traumatic Brain Injury: A Prospective Study in a Tertiary Care Trauma Center

Object:

Coagulopathy is a common occurrence following traumatic brain injury (TBI). There are various studies showing incidence and risk factors of coagulopathy and their correlation with poor outcome in adult as well as paediatric age groups. Exact incidence, associated risk factors, treatment guideline for coagulopathy and its impact on outcome are still lacking. In our study we compared the adults and paediatric age groups TBI patients for incidence and risk factors of coagulopathy and its impact on outcome.

Methods:

Prospective study of 200 patients including 152 adult patients (age > 18 years) and 48 paediatric (Age < 18 years) patients of TBI admitted in intensive care unit of trauma centre of a tertiary care centre was performed from august 2015 to march 2016. Both population were further subdivided into moderate TBI and severe TBI as per Glasgow coma score (GCS). Patient with long bone injury, chest injury and abdominal injuries, coagulation disorder, liver disease, medical disease like diabetes mellitus and hypertension were excluded from study. Coagulation profile were compared in the both groups (Adult and paediatric) and correlated with the outcome. Chi- Square test, student t test and Odds ratios were used for statistical analysis.

Results:

Mean age among the adult and paediatric population were 37.89 ± 11.88 years and 11.41 ± 5.90, respectively. Among the patient with moderate TBI, coagulopathy was seen in 30% patients of adult TBI whereas it was 12.5% among the paediatric TBI (P = 0.185). Among the severe TBI group coagulopathy was observed in 68.03% and 37.5% of adult and paediatric age group respectively (P = 0.0016). There was significant correlation found between midline shift and coagulopathy in the paediatric age group (P = 0.022; OR - 4.58). E. There was significant association of coagulopathy and contusion on CT scan among the adult population (P = 0.007; OR - 3.487) found whereas no such correlation were observed in paediatric population.

Conclusion:

Coagulopathy was significantly higher among the adult patient with severe TBI as compare to paediatric patient with severe TBI. There was no statistically significant difference in mortality among patients of both the age groups with coagulopathy.

Trauma-associated hyperfibrinolysis

Trauma-induced coagulopathy (TIC) has been considered for a long time as being due to depletion of coagulation factors secondary to blood loss, dilution and consumption. Dysfunction of the remaining coagulation factors due to hypothermia and acidosis is assumed to additionally contribute to TIC. Recent data suggest that hyperfibrinolysis (HF) represents an additional important confounder to the disturbed coagulation process. Severe shock and major tissue trauma are the main drivers of this HF. The incidence of HF is still speculative. According to visco-elastic testing of trauma patients upon emergency room admission, HF is present in approximately 2.5–7% of all trauma patients. However, visco-elastic tests provide information on severe forms of HF only. Occult HF seems to be much more common but diagnosis is still challenging. Results from a recent randomized, placebo-controlled trial suggest that the early treatment of trauma patients with tranexamic acid may result in a significant reduction of trauma-associated mortality.

The role of fibrinogen in trauma-induced coagulopathy

Fibrinogen plays an essential role in clot formation and stability. Importantly it seems to be the most vulnerable coagulation factor, reaching critical levels earlier than the others during the course of severe injury. A variety of causes of fibrinogen depletion in major trauma have been identified, such as blood loss, dilution, consumption, hyperfibrinolysis, hypothermia and acidosis. Low concentrations of fibrinogen are associated with an increased risk of diffuse microvascular bleeding. Therefore, repeated measurements of plasma fibrinogen concentration are strongly recommended in trauma patients with major bleeding. Recent guidelines recommend maintaining plasma fibrinogen concentration at 1.5–2 g/l in coagulopathic patients. It has been shown that early fibrinogen substitution is associated with improved outcome.

Acute Traumatic Coagulopathy Accompanying Isolated Traumatic Brain Injury is Associated with Worse Long-Term Functional and Cognitive Outcomes

BACKGROUND

Approximately one-third of patients with isolated traumatic brain injury (iTBI) present with acute traumatic coagulopathy (ATC). ATC is associated with increased morbidity and mortality. Its effects on long-term functional and cognitive outcomes are not as well characterized.

METHODS

Data from the Citicoline Brain Injury Treatment Trial (COBRIT) were analyzed retrospectively. Exclusion criteria were renal failure or malignancy, and any extracranial injury severity score >3. ATC was defined as INR > 1.3, PTT > 38 s, or platelets < 100 K, determined at baseline, and during the first 7 days of hospitalization.

RESULTS

Six hundred forty-seven patients were included; 21 % were found to have ATC. Highest incidence occurred at baseline, and Day Two. Forty-two percent of ATC patients had a GCS < 8, compared with 11.3 % of non-ATC patients (p < 0.001). A significantly higher proportion of ATC patients was transfused blood products, required greater than 4L of fluids, demonstrated hyperthermia and hypothermia, were hypotensive and demonstrated elevated lactate when compared to non-ATC patients. In-hospital mortality, mean hospital length of stay, incidence of DVT and seizures were also significantly higher in ATC patients. A significantly lower portion of ATC patients had good outcomes on the GOS-E (i.e., score > 6), and the DRS (i.e., score < 2) at 180 days, for which ATC was found to be an independent predictor with binary logistic regression. ATC patients also performed significantly worse on several components of the CVLT-II at 180 days.

CONCLUSIONS

ATC accompanying iTBI is associated with worse functional and cognitive outcomes at 180 days.

Pathophysiology of trauma-induced coagulopathy: disseminated intravascular coagulation with the fibrinolytic phenotype

In severe trauma patients, coagulopathy is frequently observed in the acute phase of trauma. Trauma-induced coagulopathy is coagulopathy caused by the trauma itself. The pathophysiology of trauma-induced coagulopathy consists of coagulation activation, hyperfibrino(geno)lysis, and consumption coagulopathy. These pathophysiological mechanisms are the characteristics to DIC with the fibrinolytic phenotype.

Dynamics of fibrinogen in acute phases of trauma

Fibrinogen is a unique precursor of fibrin and cannot be compensated for by other coagulation factors. If plasma fibrinogen concentrations are insufficient, hemostatic clots cannot be formed with the appropriate firmness. In severe trauma patients, plasma fibrinogen concentrations decrease earlier and more frequently than other coagulation factors, predicting massive bleeding and death. We review the mechanisms of plasma fibrinogen concentration decrease, which include coagulation activation-induced consumption, hyper-fibrino(geno)lysis-induced degradation, and dilution by infusion/transfusion. Understanding the mechanisms of plasma fibrinogen concentration decrease in severe trauma patients is crucial.

Thrombocytopenia and Critical Care Medicine

Platelet transfusions play an important role in the treatment of critically ill patients. Like any blood component, however, there are various aspects of platelet transfusion therapy that need be considered by the intensivist. These include the proper dose and type of platelet component to infuse, as well as the route and method of administration. Methods to reduce the volume of the transfused platelets, for example, must ensure that the infused platelets will be functional and viable, posttransfusion. Treatment and diagnosis of the HLA alloimmunized recipient can pose a serious challenge to the clinician and an obstacle to adequate platelet therapy. An ICU patient for whom an adequate posttransfusion platelet increment cannot be achieved is at great risk of suffering a fatal hemorrhage. The ICU physician should be aware of the techniques used in modern transfusion practice to avoid having to deal with this complication. Adverse reactions to platelet transfusion include not only serologic ones, but those related to febrile and allergic complications, as well as infectious complications. The latter group includes diseases caused by infection with cytomegalovirus, bacteria, and a cadre of viruses including HIV and hepatitis. The clinical approach to thrombocytopenia in the ICU will be covered in some detail in an effort to review many of the conditions associated with recipient thrombocytopenia, including ITP, TTP, dilutional thrombocytopenia, DIC, surgery, HELLP syndrome, and drug-induced thrombocytopenia. Unfortunately the treatment approaches traditionally used are not always derived from evidence-based studies. This review covers many of these topics in an attempt to help physicians become better able to manage thrombocytopenia in the ICU and thus provide the best transfusion therapy for their patients.

Thrombocytopenia in the Intensive Care Unit Setting

Thrombocytopenia is a commonly encountered labora tory abnormality in the intensive care unit setting. Al though moderate degrees of thrombocytopenia may be dismissed as clinically trivial, severe thrombocytopenia can have catastrophic consequences. This review di vides the potential pathogenesis of thrombocytopenia into three pathophysiological categories: (1) produc tive, (2) consumptive, and (3) distributional. The im portant etiologies and appropriate therapies for throm bocytopenia in each of these categories are discussed. We have attempted to emphasize the underlying patho genic mechanisms as well as highlight the diagnostic dilemmas likely to be faced by intensive care unit physi cians. Although this review stresses those thrombocyto penic disorders most likely to be encountered in the intensive care unit, chronic etiologies of thrombocy topenia are also discussed because preexistent throm bocytopenia will further complicate the care of any acutely ill intensive care unit patient.

Isolated traumatic brain injury in patients with cirrhosis: do different treatment paradigms result in increased mortality?

BACKGROUND

Cirrhosis is associated with increased mortality in trauma, yet its effects on outcomes after traumatic brain injury (TBI) are unclear. We hypothesized that cirrhosis adversely effects mortality and increases complications after TBI.

METHODS

Cirrhotic patients with isolated TBI were matched with noncirrhotic TBI patients in a 3:1 ratio based on age, sex, injury mechanism, and injury severity score at our academic, level 1 trauma center.

RESULTS

Of the 8,748 patients with isolated TBI, 65 patients had concurrent cirrhosis. Cirrhotic patients had increased mortality compared with matched controls (31% vs 17%, P = .03) and were less likely to undergo emergent neurosurgical operation (12% vs 25%, P = .03). There was no difference in admission Glasgow Coma Score, type of intracranial hemorrhage, length of stay, or complications between the groups.

CONCLUSIONS

Cirrhotic patients have increased mortality after TBI and were less likely to undergo operative intervention. New treatment paradigms may be needed to improve outcomes for cirrhotic patients suffering TBI.

Traumatic brain injury associated coagulopathy

BACKGROUND

The presence of coagulopathy is common after severe trauma. The aim of this study was to identify whether isolated severe traumatic brain injury (TBI) is an independent risk factor for coagulopathy.

METHODS

Prospective observational cohort of adult patients admitted to a Level I Trauma Center within 6 h of injury. Patients were categorized according to the abbreviated injury scale (AIS): Group 1-isolated severe TBI (AIS head ≥ 3 + AIS non-head < 3); Group 2-severe multisystem trauma associated with severe TBI (AIS head ≥ 3 + AIS non-head ≥ 3); Group 3-severe multisystem trauma without TBI (AIS head < 3 + AIS non-head ≥ 3). Primary outcome was the development of coagulopathy. Secondary outcome was in-hospital mortality.

RESULTS

Three hundred and forty five patients were included (Group 1 = 48 patients, Group 2 = 137, and Group 3 = 160). Group 1 patients had the lowest incidence of coagulopathy and disseminated intravascular coagulopathy, and in general presented with better coagulation profile measured by either classic coagulation tests, thromboelastography or clotting factors. Isolated severe TBI was not an independent risk factor for the development of coagulopathy (OR 1.06; 0.35-3.22 CI, p = 0.92), however, isolated severe TBI patients who developed coagulopathy had higher mortality rates than isolated severe TBI patients without coagulopathy (66 vs. 16.6 %, p < 0.05). The presence of coagulopathy (OR 5.61; 2.65-11.86 CI, p < 0.0001) and isolated severe TBI (OR 11.51; 3.9-34.2 CI, p < 0.0001) were independent risk factors for in-hospital mortality.

CONCLUSION

Isolated severe TBI is not an independent risk factor for the development of coagulopathy. However, severe TBI patients who develop coagulopathy have extremely high mortality rates.

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

Traumatic brain injury (TBI) has long been associated with coagulopathy; however, the time course of coagulation/fibrinolytic parameters in the acute phase of TBI remains unclear. The purpose of the study was to analyze the time course of coagulation/fibrinolytic parameters in the acute phase of TBI and to elucidate parameter relationships to prognosis. We retrospectively evaluated 234 patients with severe isolated TBI with initial blood samples obtained no more than 1 h after injury. Platelet count, prothrombin time, activated partial thromboplastin time (aPTT), plasma levels of fibrinogen, and D-dimer were measured on arrival in the emergency department and 3, 6, and 12 h after injury. Multivariate logistic regression analysis was performed to identify risk factors for poor prognosis at each time point. From hospital admission to 12 h after injury, an elevated D-dimer level was a significant negative prognostic indicator (admission: p < 0.0001; 3 h after injury: p = 0.0005; 6 h after injury: p = 0.005; 12 h after injury: p = 0.0009). An upward trend of aPTT on admission and 3 h after injury was also a significant negative prognostic indicator (admission: p = 0.0011; 3 h after injury: p = 0.013). On multivariate logistic regression analysis, which included all initial variables, independent risk factors for poor prognosis included older age (p = 0.0005), low Glasgow Coma Scale score (p < 0.0001), high Abbreviated Injury Score (p = 0.015), aPTT >30.2 sec (p = 0.019), and elevated D-dimer level (p = 0.0005). We concluded that D-dimer is the best coagulation/fibrinolytic parameter to monitor for prediction of outcome.

Evolving beyond the vicious triad: Differential mediation of traumatic coagulopathy by injury, shock, and resuscitation

BACKGROUND

A subset of trauma patients with critical injury present with coagulopathy, portending markedly worse outcomes. Clinical practice is evolving to treat the classical risk factors of hypothermia, hemodilution, and acidosis; however, coagulopathy persists even in the absence of these factors. We sought to determine the relative importance of injury- and shock-specific factors compared with resuscitation-associated factors in coagulopathy after trauma.

METHODS

Comprehensive demographic data, laboratory data, and outcomes data were prospectively collected from seven trauma centers over 8 years (November 2003 to August 2011) as part of the Inflammation and the Host Response to Injury Large-Scale Collaborative Program. A total of 1,537 critically injured patients with blunt trauma and hemorrhagic shock were analyzed to evaluate predictors of admission coagulopathy (international normalized ratio [INR] ≥ 1.3), multiorgan failure, and mortality.

RESULTS

Of 1,537 patients, 578 (37.6%) had admission INR of 1.3 or greater. Coagulopathic patients had more severe injury, more severe base deficit and lactate levels, as well as lower admission temperature, lower pH, and higher prehospital crystalloid volume (all p < 0.001). Coagulopathic patients required more blood products and mechanical ventilation and had higher rates of nosocomial infection, multiorgan failure, and mortality (all p < 0.02). Injury severity, temperature, and acidosis (all p < 0.02) independently predicted coagulopathy in multivariate analysis, with a significant interaction between lactate and prehospital crystalloid. In Cox regression models, however, coagulopathy itself remained an independent predictor of both multiorgan failure and mortality (p < 0.02) even when adjusted for injury severity, shock, and elements of the vicious triad.

CONCLUSION

Most patients with coagulopathy after trauma have mixed risk factors; however, coagulopathy has deleterious effects independent of injury severity, shock, and the vicious triad. Better understanding of the biochemical mechanisms of acute traumatic coagulopathy may facilitate biochemically targeted resuscitation strategies and improve outcomes.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level II.

Traumatic brain injury is not associated with coagulopathy out of proportion to injury in other body regions

BACKGROUND

Coagulopathy following trauma is associated with poor outcomes. Traumatic brain injury has been associated with coagulopathy out of proportion to other body regions. We hypothesized that injury severity and shock determine coagulopathy independent of body region injured.

METHODS

We performed a prospective, multicenter observational study at three Level 1 trauma centers. Conventional coagulation tests (CCTs) and rapid thrombelastography (r-TEG) were used. Admission vital signs, base deficit (BD), CCTs, and r-TEG data were collected. The Abbreviated Injury Scale (AIS) score and Injury Severity Score (ISS) were obtained. Severe injury was defined as AIS score greater than or equal to 3 for each body region. Patients were grouped according to their dominant AIS region of injury. Dominant region of injury was defined as the single region with the highest AIS score. Patients with two or more regions with the same greatest AIS score and patients without a region with an AIS score greater than or equal to 3 were excluded. Coagulation parameters were compared between the dominant AIS region. Significant hypoperfusion was defined as BD greater than or equal to 6.

RESULTS

Of the 795 patients enrolled, 462 met criteria for grouping by dominant AIS region. Patients were predominantly white (59%), were male (75%), experienced blunt trauma (71%), and had a median ISS of 25 (interquartile range, 14-29). Patients with BD greater than or equal to 6 (n = 110) were hypocoagulable by CCT and r-TEG compared with patients with BD less than 6 (n = 223). Patients grouped by dominant AIS region showed no significant differences for any r-TEG or CCT parameter. Patients with BD greater than or equal to 6 demonstrated no difference in any r-TEG or CCT parameter between dominant AIS regions.

CONCLUSION

Coagulopathy results from a combination of tissue injury and shock independent of the dominant region of injury. With the use of AIS as a measure of injury severity, traumatic brain injury was not independently associated with more profound coagulopathy.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

Early hemorrhagic progression of traumatic brain contusions: frequency, correlation with coagulation disorders, and patient outcome: a prospective study

The focus of this paper is to identify and quantify risk factors for early hemorrhagic progression of brain contusions (HPC) in patients with traumatic brain injury (TBI) and to evaluate their impact on patients' outcome. Further, based on abnormal values in routine blood tests, the role of trauma-induced coagulopathy is analyzed in detail. Therefore, a prospective study of 153 TBI patients was completed at one institution between January 2008 and June 2012. The collected data included demographics, initial Glasgow Coma Scale pupillary response, initial and 6 h follow-up computed tomography scan findings, coagulation parameters (international normalized ratio, partial thromboplastin time, platelet count, fibrinogen, D-dimer and factor XIII), as well as outcome data using the modified Rankin score at discharge and after one year. The overall rate of early HPC within the first 6 h was 43.5%. The frequency of coagulopathy was 47.1%. When analyzing for risk factors that independently influenced outcome in the form of mRS ≥4 at both points, the following variables appeared: elevated D-dimer level (≥10,000 μg/L), HPC, and initial brain contusions ≥3 cm. Patients sustaining early HPC had a hazard ratio of 5.4 for unfavorable outcome at discharge (p=0.002) and of 3.9 after one year (p=0.006). Overall, patients who developed early HPC were significantly more likely to be gravely disabled or to die. Unfavorable neurological outcome after an isolated TBI is determined largely by early HPC and coagulopathy, which seem to occur very frequently in TBI patients, irrespective of the severity of the trauma.

Coagulopathy associated with traumatic brain injury

Coagulopathy is often observed after traumatic brain injury (TBI), but the pathogenic mechanisms of this phenomenon remain elusive. Brain injury is the leading cause of trauma deaths, and the development of coagulopathy after TBI is associated with increased morbidity and mortality in these patients. The coagulopathy after TBI comprises a hypocoagulable and a hypercoagulable state with hemorrhagic and thrombotic phenotypes that are both associated with worse outcome. Some theories of its pathogenesis include massive release of tissue factor, altered protein C homeostasis, microparticle upregulation, and platelet hyperactivity. This article aims to examine the coagulopathy associated with blunt head injury, to review its effect on progression of hemorrhagic injury, and to discuss the possible relevant pathophysiological mechanisms.

Assessment of coagulopathy, endothelial injury, and inflammation after traumatic brain injury and hemorrhage in a porcine model

BACKGROUND

Traumatic brain injury (TBI) and hemorrhagic shock (HS) can be associated with coagulopathy and inflammation, but the mechanisms are poorly understood. We hypothesized that a combination of TBI and HS would disturb coagulation, damage the endothelium, and activate inflammatory and complement systems.

METHODS

A total of 33 swine were allocated to either TBI + HS (n = 27, TBI and volume-controlled 40% blood loss) or controls (n = 6, anesthesia and instrumentation). TBI + HS animals were left hypotensive (mean arterial pressure, 30-35 mm Hg) for 2 hours. Blood samples were drawn at baseline, 3 minutes and 15 minutes after injury, as well as following 2 hours of hypotension. Markers of coagulation, anticoagulation, endothelial activation/glycocalyx shedding, inflammation, complement, and sympathoadrenal function were measured.

RESULTS

The TBI + HS group demonstrated an immediate (3 minutes after injury) activation of coagulation (prothrombin fragment 1 + 2, 289 ng/mL vs. 232 ng/mL, p = 0.03) and complement (C5a, 2.83 ng/mL vs. 2.05 ng/mL, p = 0.05). Shedding of the endothelial glycocalyx (syndecan 1) was evident 15 minutes after injury (851.0 ng/ml vs. 715.5 ng/ml, p = 0.03) while inflammation (tumor necrosis factor α [TNF-α], 81.1 pg/mL vs. 50.8 pg/mL, p = 0.03) and activation of the protein C system (activated protein C, 56.7 ng/mL vs. 26.1 ng/mL, p = 0.01) were evident following the 2-hour hypotension phase.

CONCLUSION

The combination of TBI and shock results in an immediate activation of coagulation and complement systems with subsequent endothelial shedding, protein C activation, and inflammation.

Brain ischemia in patients with intracranial hemorrhage: pathophysiological reasoning for aggressive diagnostic management

Patients with intracranial hemorrhage have to be managed aggressively to avoid or minimize secondary brain damage due to ischemia, which contributes to high morbidity and mortality. The risk of brain ischemia, however, is not the same in every patient. The risk of complications associated with an aggressive prophylactic therapy in patients with a low risk of brain ischemia can outweigh the benefits of therapy. Accurate and timely identification of patients at highest risk is a diagnostic challenge. Despite the availability of many diagnostic tools, stroke is common in this population, mostly because the pathogenesis of stroke is frequently multifactorial whereas diagnosticians tend to focus on one or two risk factors. The pathophysiological mechanisms of brain ischemia in patients with intracranial hemorrhage are not yet fully elucidated and there are several important areas of ongoing research. Therefore, this review describes physiological and pathophysiological aspects associated with the development of brain ischemia such as the mechanism of oxygen and carbon dioxide effects on the cerebrovascular system, neurovascular coupling and respiratory and cardiovascular factors influencing cerebral hemodynamics. Consequently, we review investigations of cerebral blood flow disturbances relevant to various hemodynamic states associated with high intracranial pressure, cerebral embolism, and cerebral vasospasm along with current treatment options.

Hemostasis and alterations of the central nervous system

Modulation of coagulation has been successfully applied to ischemic disorders of the central nervous system (CNS). Some components of the coagulation system have been identified in the CNS, yet with limited exception their functions have not been clearly defined. Little is known about how events within the cerebral tissues affect hemostasis. Nonetheless, the interaction between cerebral cells and vascular hemostasis and the possibility that endogenous coagulation factors can participate in functions within the neurovascular unit provide intriguing possibilities for deeper insight into CNS functions and the potential for treatment of CNS injuries. Here, we consider the expression of coagulation factors in the CNS, the coagulopathy associated with focal cerebral ischemia (and its relationship to hemorrhagic transformation), the use of recombinant tissue plasminogen activator (rt-PA) in ischemic stroke and its study in animal models, the impact of rt-PA on neuron and CNS structure and function, and matrix protease generation and matrix degradation and hemostasis. Interwoven among these topics is evidence for interactions of coagulation factors with and within the CNS. How activation of hemostasis occurs in the cerebral tissues and how the brain responds are difficult questions that offer many research possibilities.

Coagulopathy as prognostic marker in acute traumatic brain injury

Context:

Coagulopathy frequently occurs following traumatic brain injury (TBI) and usually occurs 6-72 hour post-trauma. The incidence and the probable risk factors for development of coagulopathy and poor outcome following TBI are largely unknown and vary considerably.

Aims:

To assess the incidence and probable risk factors for development of coagulopathy and to identify the risk factors for poor outcome in terms of median survival time following TBI.

Materials and Methods:

In this prospective study over two years, patients of isolated moderate and severe traumatic brain injury (GCS≤12) admitted to trauma center had coagulation profile (PT, APTT, thrombin time, fibrinogen and D-dimer), arterial lactate and ABG analysis done on day of admission and on day three. Coagulopathy was defined as prothrombin time (PT) or/and activated partial thromboplastin time (APTT) more than 1.5 times the normal control. Incidence of in-hospital mortality was assessed in all cases.

Statistical Analysis:

A stepwise logistic regression analysis was performed to identify risk factors for coagulopathy and mortality in these patients.

Results:

A total of 208 patients were enrolled in the study. The mean age was 32 ± 12 years and mean GCS was 7.1 ± 2.8. Coagulopathy was present in 46% (n = 96) of patients. Risk factors for development of coagulopathy were found out to be severity of head injury (OR: 2.81), elevated D-dimer (OR: 3.43), low hemoglobin (OR: 3.13), and effaced cisterns in the CT scan (OR: 2.72). Presence of coagulopathy (OR: 2.97) and severity of head injury (OR: 5.70) strongly predicted poor outcome, and were associated with a decreased median survival time.

Conclusions:

There is a high incidence of coagulopathy following TBI. The presence of coagulopathy as well as of severity of TBI are strong predictors of in-hospital mortality in these patients.

Kidney Transplantation from Donors with Severe Disseminated Intravascular Coagulation

Disseminated intravascular coagulation (DIC) is a syndrome characterized by massive formation of thrombin, which can lead to renal dysfunction or failure. Many transplant centers are reluctant to accept the kidneys from donors with DIC especially if renal dysfunction is present. We developed protocol of machine perfusion followed by tissue plasminogen activator (tPA) infusion in order to treat and evaluate DIC kidneys prior to transplantation. The kidneys were placed on machine preservation with tPA added to the perfusate prior to transplantation. Three kidneys were transplanted from two donors who sustained gunshot injuries to the brain. A biopsy at the time of organ recovery documented widespread fibrin thrombi in approximately 80% of the glomeruli. Serial biopsies showed interval improvement following machine perfusion and a normal appearing kidney three months after successful transplantation. The histological presence of DIC in a deceased organ donor, even if associated with renal dysfunction, is not a contraindication to renal transplantation. Machine perfusion and tPA infusions may contribute to the recovery and successful transplantation of such kidneys.

Coagulopathy after traumatic brain injury

Traumatic brain injury has long been associated with abnormal coagulation parameters, but the exact mechanisms underlying this phenomenon are poorly understood. Coagulopathy after traumatic brain injury includes hypercoagulable and hypocoagulable states that can lead to secondary injury by either the induction of microthrombosis or the progression of hemorrhagic brain lesions. Multiple hypotheses have been proposed to explain this phenomenon, including the release of tissue factor, disseminated intravascular coagulation, hyperfibrinolysis, hypoperfusion with protein C activation, and platelet dysfunction. The diagnosis and management of these complex patients are difficult given the lack of understanding of the underlying mechanisms. The goal of this review is to summarize the current knowledge regarding the mechanisms of coagulopathy after blunt traumatic brain injury. The current and emerging diagnostic tools, radiological findings, treatment options, and prognosis are discussed.

Haemostatic and cranial computed tomography characteristics in patients with acute and delayed coagulopathy after isolated traumatic brain injury

PRIMARY OBJECTIVE

To investigate whether the development of coagulopathy at different stages after isolated traumatic brain injury (TBI) is associated with distinct cranial computed tomography characteristics.

RESEARCH DESIGN

Retrospective cohort study in 226 patients with moderate-to-severe isolated TBI who were categorized as subjects without coagulopathy or with acute temporary, acute sustained or delayed coagulopathy.

METHODS AND PROCEDURES

Coagulopathy was defined as an activated partial thromboplastin time >40 seconds and/or prothrombin time (PT) >1.2 and/or platelet count <120*10(9)l(-1). Cranial CT scans were assigned to the six-point Traumatic Coma Data Bank (TCDB) CT-classification.

MAIN OUTCOMES AND RESULTS

Coagulopathy occurred in 44% of patients in the first 24-hours post-trauma. Patients with acute, sustained coagulopathy showed a prolonged PT (1.64 ± 0.89) when compared to patients without (1.03 ± 0.07), acute temporary (1.27 ± 0.22) or delayed coagulopathy (1.08 ± 0.06; p < 0.05). Patients with acute temporary or delayed coagulopathy had the worst TCDB CT classification scores, while mortality rates were the highest in patients with sustained or delayed coagulopathy.

CONCLUSIONS

Not only the mere presence of coagulopathy, but also the course of haemostatic alterations following neurotrauma may hold predictive value for patient outcome, irrespective of the severity level of cerebral injury.

Bleeding and thrombosis in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) has evolved from being a deadly to a highly curable disease, due to targeted molecular therapy with all-trans retinoic acid (ATRA). As a result, the incidence of early hemorrhagic deaths for which APL is notorious has reduced to 5-10% as reported in clinical trials. These results are not replicated outside of clinical trials as is evident from recent population-based registries. High incidence of early hemorrhagic deaths remains the greatest contributor to treatment failure in this otherwise curable leukemia. Additionally, thrombosis is now being increasingly recognized in APL patients and may be associated with ATRA usage.

Multicenter evaluation of the course of coagulopathy in patients with isolated traumatic brain injury: relation to CT characteristics and outcome

This prospective multicenter study investigated the association of the course of coagulation abnormalities with initial computed tomography (CT) characteristics and outcome in patients with isolated traumatic brain injury (TBI). Patient demographics, coagulation parameters, CT characteristics, and outcome data of moderate and severe TBI patients without major extracranial injuries were prospectively collected. Coagulopathy was defined as absent, early but temporary, delayed, or early and sustained. Delayed/sustained coagulopathy was associated with a higher incidence of disturbed pupillary responses (40% versus 27%; p<0.001) and higher Traumatic Coma Data Bank (TCDB) CT classification (5 (2-5) versus 2 (1-5); p=0.003) than in patients without or with early, but short-lasting coagulopathy. The initial CT of patients with delayed/sustained coagulopathy more frequently showed intracranial hemorrhage and signs of raised intracranial pressure (ICP) compared to patients with early coagulopathy only. This was paralleled by higher in-hospital mortality rates (51% versus 33%; p<0.05), and poorer 6-month functional outcome in patients with delayed/sustained coagulopathy. The relative risk for in-hospital mortality was particularly related to disturbed pupillary responses (OR 8.19; 95% CI 3.15,21.32; p<0.001), early, short-lasting coagulopathy (OR 6.70; 95% CI 1.74,25.78; p=0.006), or delayed/sustained coagulopathy (OR 5.25; 95% CI 2.06,13.40; p=0.001). Delayed/sustained coagulopathy is more frequently associated with CT abnormalities and unfavorable outcome at 6 months after TBI than early, short-lasting coagulopathy. Our finding that not only the mere presence but also the time course of coagulopathy holds predictive value for patient outcome underlines the importance of systematic hemostatic monitoring over time in TBI.

Thromboelastometric (ROTEM) findings in patients suffering from isolated severe traumatic brain injury

Severe traumatic brain injury (sTBI) is often accompanied by coagulopathy and an increased risk of bleeding. To identify and successfully treat bleeding disorders associated with sTBI, rapid assessment of coagulation status is crucial. This retrospective study was designed to assess the potential role of whole-blood thromboelastometry (ROTEM(®), Tem International, Munich, Germany) in patients with isolated sTBI (abbreviated injury scale [AIS](head) ≥3 and AIS(extracranial) <3). Blood samples were obtained immediately following admission to the emergency room of the Trauma Centre Salzburg in Austria. ROTEM analysis (EXTEM, INTEM, and FIBTEM tests) and standard laboratory coagulation tests (prothrombin time index [PTI, percentage of normal prothrombin time], activated partial thromboplastin time [aPTT], fibrinogen concentration, and platelet count) were compared between survivors and non-survivors. Out of 88 patients with sTBI enrolled in the study, 66 survived and 22 died. PTI, fibrinogen, and platelet count were significantly higher in survivors (p<0.005). Accordingly, aPTT was shorter in this group (p<0.0001). ROTEM analysis revealed shorter clotting times in extrinsically activated thromboelastometric test (EXTEM) and intrinsically activated thromboelastometric test (INTEM) (p<0.001), shorter clot formation times in EXTEM and INTEM (p<0.0001), and higher maximum clot firmness in EXTEM, INTEM, and FIBTEM (p<0.01) in survivors compared with non-survivors. Logistic regression analysis revealed extrinsically activated thromboelastometric test with cytochalasin D (FIBTEM) MCF and aPTT to have the best predictive value for mortality. According to the degree of coagulopathy, non-survivors received more RBC (p=0.016), fibrinogen concentrate (p=0.01), and prothrombin complex concentrate (p<0.001) within 24 h of arrival in the emergency room. ROTEM testing appeared to offer an early signal of severe life-threatening sTBI. Further studies are warranted to confirm these results and to investigate the role of ROTEM in guiding coagulation therapy.

Validating the incidence of coagulopathy and disseminated intravascular coagulation in patients with traumatic brain injury--analysis of 242 cases

OBJECTIVES

To estimate the incidence of coagulopathy and disseminated intravascular coagulation (DIC) in patients with traumatic brain injury (TBI) and to investigate its relationship to patient outcome.

DESIGN

A prospective observational study.

MEASUREMENTS AND MAIN RESULTS

From January 2007 to June 2009, 242 consecutive adult patients with TBI seen in three independent hospitals were recruited. Glasgow Coma Score (GCS) on admission, platelet counts (PLT), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), D-dimer (D-DT) and DIC scores were recorded for each case on admission. Clinical outcome was measured according to the Glasgow Outcome Scale (GOS) at 3 months after injury. Statistical analysis was carried using Student's t-test, one-way analysis of variance (ANOVA), and Tudey test. Coagulation abnormalities were present in approximately 50% of patients with TBI. Prolonged PT and increased D-DT and FIB levels occurred in patients with more severe brain injury and poorer outcome, and these findings were statistically significant.

CONCLUSIONS

Coagulation changes, particularly the incidence of DIC, may occur within 6 h after TBI and are more pronounced in patients with severe injuries and poor outcome. PT, D-DT levels and more comprehensively a DIC scores may be useful prognostic indicators in patients with TBI.

Acute and delayed mild coagulopathy are related to outcome in patients with isolated traumatic brain injury

INTRODUCTION

The relationship between isolated traumatic brain injury (TBI) associated coagulopathy and patient prognosis frequently lacks information regarding the time course of coagulation disorders throughout the post-traumatic period. This study was conducted to assess the prevalence and time course of post-traumatic coagulopathy in patients with isolated TBI and the relationship of these hemostatic disorders with outcome.

METHODS

The local Human Subjects Committee approved the study. We retrospectively studied the medical records of computed tomography (CT)-confirmed isolated TBI patients with an extracranial abbreviated injury scale (AIS) <3 who were primarily referred to a Level 1 trauma centre in Amsterdam (n = 107). Hemostatic parameters including activated partial thromboplastin time (aPTT), prothrombin time (PT), platelet count, hemoglobin, hematocrit, glucose, pH and lactate levels were recorded throughout a 72-hour period as part of a routine standardized follow-up of TBI. Coagulopathy was defined as a aPPT >40 seconds and/or a PTT in International Normalized Ratio (INR) >1.2 and/or a platelet count <120*109/l.

RESULTS

Patients were mostly male, aged 48 ± 20 years with a median injury severity score of 25 (range 20 to 25). Early coagulopathy as diagnosed in the emergency department (ED) occurred in 24% of all patients. The occurrence of TBI-related coagulopathy increased to 54% in the first 24 hours post-trauma. In addition to an increased age and disturbed pupillary reflex, both coagulopathy upon ED arrival and during the first 24 hours post-trauma provided an independent prognostic factor for unfavorable outcome (odds ratio (OR) 3.75 (95% CI 1.07 to 12.51; P = 0.04) and OR 11.61 (2.79 to 48.34); P = 0.003).

CONCLUSIONS

Our study confirms a high prevalence of early and delayed coagulopathy in patients with isolated TBI, which is strongly associated with an unfavorable outcome. These data support close monitoring of hemostasis after TBI and indicate that correction of coagulation disturbances might need to be considered.

[Coagulation disorders after traumatic brain injury: pathophysiology and therapeutic implications]

Early activation of coagulation is common after traumatic brain injury. Its origin is probably mainly intracerebral, due to tissue factor release from the injured brain. Abnormalities in blood coagulation tests are associated with poor neurological prognosis. Coagulation activation may induce disseminated intravascular coagulation and fibrinolysis. Disseminated intravascular coagulation is linked to brain ischemia caused by intravascular microthrombosis. This review will focus on pathophysiology of coagulation disorders after traumatic brain injury, and on their implications for therapeutic approaches.

Abnormal coagulation tests are associated with progression of traumatic intracranial hemorrhage

BACKGROUND

Intracranial hemorrhage (ICH) is common in traumatic brain injury (TBI) and a major determinant of death and disability. ICH commonly increases in size and coagulopathy has been implicated in such progression. We investigated the association between coagulopathy diagnosed by routine laboratory tests and ICH progression.

METHODS

Subgroup post hoc analysis from a randomized controlled trial including adult patients with blunt severe TBI (Glasgow Coma Scale score <or=8) and repeat computerized tomography scans in 48 hours. Coagulopathy was defined as international normalized ratio >or=1.3, activated partial thromboplastin time >or=35, or platelet count (PLT) <or=100 x 10/L any time in the first 24 hours. Progression was any size increase or new ICH. TBI-associated coagulopathy was investigated measuring soluble tissue factor (TF) and d-dimer.

RESULTS

The ICH progressed in 37 of 72 patients (51%), in 80% if any abnormal laboratory test (coagulopathic patients) versus 36% in noncoagulopathic (p = 0.0004). Abnormal international normalized ratio (odds ratio [OR] = 4.09; 95% confidence interval [CI] = 1.29-12.95; p = 0.017), PLT (OR = 12.59; 95% CI = 1.52-108.57; p = 0.019), head Abbreviated Injury Scale (AIS) (OR = 1.82; 95% CI = 1.15-2.88; p = 0.011) were significantly associated with progression (univariate analysis). In a multiple logistic regression, only head AIS (OR = 1.81; 95% CI 1.10-2.98; p = 0.0198) and PLT (OR = 11.8; 95% CI = 1.38-101.23; p = 0.024) correlated with progression. All patients with abnormal partial thromboplastin time experienced progression. ICH progression carried a 5-fold higher odds of death; 32% with progression died versus 8.6% without. Age, head AIS, Injury Severity Score, and d-dimer were also associated with mortality. Tissue factor was not associated with progression or mortality.

CONCLUSION

This study demonstrates an association between coagulopathy, diagnosed by routine laboratorial tests in the first 24 hours, with ICH progression; and ICH progression with mortality in patients with severe TBI. The causal relationship between coagulopathy and ICH progression will require further studies.