Implications of fibrinogenolysis in patients with closed head injury

Fibrinogen; a predictor of injury severity and mortality among patients with traumatic brain injury in Sub-Saharan Africa: A cross-sectional observational study

Studies show that fibrinogen concentrations <2 g/L in patients with traumatic brain injury (TBI) is associated with increased mortality. However, little is known regarding fibrinogen levels and TBI severity as well as mortality in sub-Saharan Africa despite shouldering a high burden of TBI. We therefore set out to determine whether fibrinogen levels are associated with TBI severity and outcome. To determine the sensitivity and specificity of fibrinogen levels and the association with severity and mortality among TBI patients at Mulago Hospital. We prospectively enrolled 213 patients with TBI aged between 13 and 60 years of age and presenting within 24 hours of injury. Patients with preexisting coagulopathy, concurrent use of anticoagulant or antiplatelet agents, preexisting hepatic insufficiency, diabetes mellitus and who were pregnant were excluded. Fibrinogen levels were determined using the Clauss fibrinogen assay. Logistic regression analyses were conducted to identify the association between fibrinogen level and 7-day outcomes. Majority of the patients were male (88.7%) and nearly half were aged 30 or less (48.8%). Fibrinogen levels <2 g/L were observed in 35.1% of the study participants. The average time spent in the study was 3.7 ± 2.4 days. The sensitivity and specificity using fibrinogen <2 g/L was 56.5% and 72.9% respectively. Fibrinogen levels predict TBI severity with an AUC = 0.656 (95% CI 0.58-0.73: P = .000) Fibrinogen levels <2 g/L (hypofibrinogenemia) were independently associated with severe TBI. (Adjusted odds ratio 2.87 CI, 1.34-6.14: P = .007). Levels above 4.5 g/L were also independently associated with injury severity (adjusted odds ratio 2.89, CI 1.12-7.48: P < .05) Fibrinogen levels more than 4.5 g/L were independently associated with mortality (OR 4.5, CI; 1.47-13.61, P < .05). The fibrinogen level is a useful tool in predicting severity including mortality of TBI. Fibrinogen levels may be used as an additional tool to screen TBI patients for injury severity especially among patients with Glasgow coma scale scores of <14.

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.

Fibrinogen; a predictor of injury severity and mortality among patients with traumatic brain injury in Sub-Saharan Africa: a prospective study

Introduction

Fibrinogen levels drop quicker than any other factors in severe trauma such as Traumatic Brain Injury (TBI). Contemporaneous studies show that fibrinogen concentrations < 2 g/L are strongly related to mortality. However, little is known regarding fibrinogen levels and TBI severity as well as mortality in sub-Saharan Africa. We therefore set out to determine whether fibrinogen levels are associated with TBI severity and seven days outcomes.

Objectives

To determine the sensitivity and specificity of fibrinogen levels and the association with severity and mortality among TBI patients at Mulago Hospital.

Methods

We prospectively enrolled 213 patients with TBI aged between 13 and 60 years of age and presenting within 24hrs of injury. Patients with pre-existing coagulopathy, concurrent use of anticoagulant or antiplatelet agents, pre-existing hepatic insufficiency, diabetes mellitus and who were pregnant were excluded. Fibrinogen levels were determined using the Clauss fibrinogen assay.

Results

Majority of the patients were male (88.7%) and nearly half were aged 30 or less (48.8%). Fibrinogen levels less than 2g/L were observed in 74 (35.1%) of the patients while levels above 4.5 g/L were observed in 30(14.2%) of the patients. The average time spent in the study was 3.7 ± 2.4 days. The sensitivity and specificity using fibrinogen < 2g/L was 56.5% and 72.9% respectively. Fibrinogen levels predict TBI severity with an AUC = 0.656 (95% CI 0.58-0.73: p = 0.000) Fibrinogen levels < 2g/L (hypofibrinogenemia) were independently associated with severe TBI. (AOR 2.87 CI,1.34-6.14: p = 0.007). Levels above 4.5g/L were also independently associated with injury severity (AOR 2.89, CI 1.12-7.48: p < 0.05) Fibrinogen levels more than 4.5g/L were independently associated with mortality (OR 4.5, CI;1.47-13.61, p < 0.05).

Conclusions

The fibrinogen level is a useful tool in predicting severity including mortality of TBI in our settings. We recommend the routine use of fibrinogen levels in TBI patient evaluations as levels below 2g/L and levels above 4.5g/L are associated with severe injuries and mortality.

Retrospective cohort study to determine the effect of preinjury antiplatelet or anticoagulant therapy on mortality in patients with major trauma

Objective

This study aimed to compare outcomes among patients who sustained major trauma from injury with and without receiving antiplatelet therapy (APT) or anticoagulant therapy (ACT) to test the hypothesis that APT does not increase the risk of mortality. However, ACT increases the mortality risk in the acute phase of trauma.

Methods

Patients registered in the Japanese Observational body for Coagulation and Thrombolysis in Early Trauma 2 between April 2017 and March 2018 who had sustained a severe injury in any anatomic region of the body, as determined using an injury severity score (ISS) ≥ 16 were included in this retrospective cohort study. We analyzed the mortality within 24 h from the arrival using a multivariable linear regression analysis adjusted for several confounding variables.

Results

We identified 1,186 eligible participants who met the inclusion criteria for this study: 105 in the APT (cases), 1,081 in the non-antiplatelet therapy (nAPT) group (controls), 65 in the ACT (cases), and 1,121 in the non-anticoagulant therapy (nACT) group (controls). The mortality within 24 h in the ACT group was significantly higher than in the nACT group (odds ratio 4.5; 95%CI: 1.2-16.79; p = 0.025); however, there was no significant difference between the two groups with or without the antiplatelet drug (odds ratio 0.32; 95%CI: 0.04-2.79; p = 0.3) administration. Other outcomes, like the 28-day mortality, mortality at discharge, and surgery for hemostasis, were not significantly different between regular users and non-users of either antiplatelet or anticoagulant drugs.

Conclusion

Regular antiplatelet medications did not increase mortality within 24 h, 28 days, or at discharge in patients with major trauma, suggesting that standard treatment, including surgery, is sufficient.

A case of hemorrhagic shock due to intercostal artery injury that occurred during initial trauma care with multiple displaced rib fractures and traumatic head injury

Rib fractures can cause injury to some organs. We herein report a case of hemorrhagic shock due to intercostal artery injury that occurred during initial trauma care (ITC) treated by resuscitative thoracotomy (RT) and transcatheter arterial embolization (TAE) with multiple displaced rib fractures (RFs) and traumatic head injury (THI). A man in his 50s who was injured in a traffic accident was transferred to our institution by helicopter for emergency medical treatment. He underwent left thoracic drainage on site. On admission, he was diagnosed with multiple RF, THI, pelvic fracture and right humerus fracture. His D-dimer and fibrin degradation products (FDP) level were extremely elevated. However, contrast enhance CT (CECT) revealed no extravasation. At 2 h after arrival, massive hemorrhaging from his thoracic tube suddenly occurred and his blood pressure decreased to approximately 40s mmHg. CECT performed after volume resuscitation and massive transfusion revealed extravasation from the intercostal artery. Because his blood pressure could not be maintained by massive transfusion, we performed RT and TAE followed by RT. He then received intensive care and several surgical procedures were performed, including craniotomy for removal of hematoma, rib fixation and humerus fixation. He was transferred to another hospital for rehabilitation on day 63, with a GCS of 15. Hemorrhagic shock due to intercostal artery injury may occur at any time from arrival in cases with displaced RF, especially when complicated by THI.

Viscoelastic Hemostatic Assays and Outcomes in Traumatic Brain Injury: A Systematic Literature Review

BACKGROUND

Coagulopathy in traumatic brain injury (TBI) occurs frequently and is associated with poor outcomes. Conventional coagulation assays (CCA) traditionally used to diagnose coagulopathy are often not time sensitive and do not assess complete hemostatic function. Viscoelastic hemostatic assays (VHAs) including thromboelastography and rotational thromboelastography provide a useful rapid and comprehensive point-of-care alternative for identifying coagulopathy, which is of significant consequence in patients with TBI with intracranial hemorrhage.

METHODS

A systematic review was performed in accordance with PRISMA guidelines to identify studies comparing VHA with CCA in adult patients with TBI. The following differences in outcomes were assessed based on ability to diagnose coagulopathy: mortality, need for neurosurgical intervention, and progression of traumatic intracranial hemorrhage (tICH).

RESULTS

Abnormal reaction time (R time), maximum amplitude, and K value were associated with increased mortality in certain studies but not all studies. This association was reflected across studies using different statistical parameters with different outcome definitions. An abnormal R time was the only VHA parameter found to be associated with the need for neurosurgical intervention in 1 study. An abnormal R time was also the only VHA parameter associated with progression of tICH. Overall, many studies also reported abnormal CCAs, mainly activated partial thromboplastin time, to be associated with poor outcomes.

CONCLUSIONS

Given the heterogenous nature of the available evidence including methodology and study outcomes, the comparative difference between VHA and CCA in predicting rates of neurosurgical intervention, tICH progression, or mortality in patients with TBI remains inconclusive.

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.

Neurocritical Management of Traumatic Acute Subdural Hematomas

Acute subdural hematoma (ASDH) has been a major part of traumatic brain injury. Intracranial hypertension may be followed by ASDH and brain edema. Regardless of the complicated pathophysiology of ASDH, the extent of primary brain injury underlying the ASDH is the most important factor affecting outcome. Ongoing intracranial pressure (ICP) increasing lead to cerebral perfusion pressure (CPP) decrease and cerebral blood flow (CBF) decreasing occurred by CPP decrease. In additionally, disruption of cerebral autoregulation, vasospasm, decreasing of metabolic demand may lead to CBF decreasing. Various protocols for ICP lowering were introduced in neuro-trauma field. Usage of anti-epileptic drugs (AEDs) for ASDH patients have controversy. AEDs may reduce the risk of early seizure (<7 days), but, does not for late-onset epilepsy. Usage of anticoagulants/antiplatelets is increasing due to life-long medical disease conditions in aging populations. It makes a difficulty to decide the proper management. Tranexamic acid may use to reducing bleeding and reduce ASDH related death rate. Decompressive craniectomy for ASDH can reduce patient's death rate. However, it may be accompanied with surgical risks due to big operation and additional cranioplasty afterwards. If the craniotomy is a sufficient management for the ASDH, endoscopic surgery will be good alternative to a conventional larger craniotomy to evacuate the hematoma. The management plan for the ASDH should be individualized based on age, neurologic status, radiologic findings, and the patient's conditions.

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.

Early administration of fibrinogen concentrate is associated with improved survival among severe trauma patients: a single-centre propensity score-matched analysis

Background

Fibrinogen plays an important role in haemostasis during the early phase of trauma, and low fibrinogen levels after severe trauma are associated with haemostatic impairment, massive bleeding, and poor outcomes. Aggressive fibrinogen supplementation may improve haemostatic function, as fibrinogen levels deteriorate before other routine coagulation parameters in this setting. Therefore, we evaluated whether early administration of fibrinogen concentrate (FC) was associated with improved survival in severe trauma patients.

Methods

This single-centre retrospective study evaluated patients with severe trauma (injury severity score ≥ 16) who were admitted to our emergency department between January 2010 and July 2018. The exclusion criteria included age < 18 years, cardiac arrest before emergency department arrival, cervical spinal cord injury not caused by a high-energy accident, and severe burn injuries. The FC and control groups included trauma patients who received and did not receive FC within 1 h after emergency department arrival, respectively. Propensity scores were used to balance the two groups based on the trauma and injury severity score (TRISS), heart rate at emergency department admission, and age. The primary outcome was the in-hospital survival rate.

Results

The propensity scoring model had a c-statistic of 0.734, the Hosmer-Lemeshow chi-squared value was 7.036 (degrees of freedom = 8), and the non-significant p value of 0.533 indicated a good model fit. The propensity score matching created 31 matched pairs of patients, who had appropriately balanced characteristics. The FC group had a significantly higher in-hospital survival rate than the control group (log-rank p = 0.013). The FC group also used significantly higher amounts of red blood cells and fresh frozen plasma within 6 h after emergency department admission. However, the two groups had similar transfusion amounts between 6 and 24 h after emergency department admission.

Conclusions

The present study revealed that early FC administration was associated with a favourable survival rate among severe trauma patients. Therefore, FC may be useful for the early management of trauma-induced coagulopathy and may improve outcomes in this setting.

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

BACKGROUND

The association between traumatic brain injury (TBI) and coagulopathy is well established. While coagulopathy prophylaxis in TBI involves replenishing coagulation factors with fresh frozen plasma (FFP), its effectiveness is controversial. We investigated the relationship between plasma fibrinogen concentration 3 h after initiating FFP transfusion and outcomes and evaluated the correlation with D-dimer levels at admission.

METHODS

We retrospectively examined data from 380 patients with severe isolated TBI with blood samples collected a maximum of 1 h following injury. Plasma fibrinogen and D-dimer concentrations were obtained at admission, and plasma fibrinogen concentration was again assessed 3-4 h following injury. The patients were divided into two groups based on whether or not they received FFP transfusion. Patients were also divided into subgroups according their fibrinogen level: ≥ 150 mg/dL (high-fibrinogen subgroup) or < 150 mg/dL (low-fibrinogen subgroup) 3 h after injury. Demographic, clinical, radiological and laboratory data were compared between these subgroups.

RESULTS

Glasgow Outcome Scale (GOS) scores at discharge and 3 months after injury were significantly lower in the FFP transfusion group than in the FFP non-transfusion group. Among patients who received FFP, GOS scores at discharge and 3 months after injury were significantly higher in the high-fibrinogen subgroup than in the low-fibrinogen subgroup. Elevated admission D-dimer predicted subsequent fibrinogen decrease.

CONCLUSIONS

In FFP transfusion, fibrinogen level ≥ 150 mg/dL 3 h after injury was associated with better outcomes in TBI patients. Assessing the admission D-dimer and tracking the fibrinogen are crucial for optimal coagulopathy prophylaxis in TBI patients.

Predictive Factors of Poor Prognosis After Surgical Management of Traumatic Acute Subdural Hematomas: A Single-Center Series

BACKGROUND

Traumatic acute subdural hematomas (ASDHs) showed the highest mortality of intracranial hematomas. The aim of the current study was to identify predictive factors of poor prognosis among patients who were operated on.

METHODS

This is a single-center retrospective cohort study of 82 patients who underwent surgical evacuation of a traumatic ASDH between January 2009 and December 2016. The epidemiologic, clinical, radiologic, and surgical features were recorded. Postoperative outcome were assessed by the Glasgow Outcome Scale (GOS) score at 6 months. Univariate and multivariate analysis and a classification and regression tree (CART) were performed.

RESULTS

At 6 months, 76% of patients achieved an unfavorable outcome (GOS score 1-3). The context of polytrauma (P = 0.03) and ASDH thickness ≥20 mm (P = 0.02) were significantly associated with poor outcome in the multivariate analysis. The CART algorithm isolated 3 subgroups of patients with an unfavorable prognosis: polytrauma (91%), isolated head injury (HI) featuring an ASDH thickness ≥20 mm (89%), or isolated HI featuring a thickness <20 mm in a patient older than 54 years (71%). Isolated patients with HI younger than 54 years harboring an ASDH <20 mm thick had the most promising results, with 53% with a GOS score of 4 or 5.

CONCLUSIONS

The context of polytrauma, ASDH thickness, and age were major predictive factors of poor prognosis in patients with surgically evacuated traumatic ASDH. The CART algorithm using these features isolated subgroups with decreasingly unfavorable outcome, providing a relevant statistical tool to apply to future studies of traumatic ASDH.

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.

Damage Control Resuscitation for Catastrophic Bleeding

The timely recognition of shock secondary to hemorrhage from severe facial trauma or as a complication of complex oral and maxillofacial surgery presents formidable challenges. Specific hemostatic disorders are induced by hemorrhage and several extreme homeostatic imbalances may appear during or after resuscitation. Damage control resuscitation has evolved from massive transfusion to a more complex therapeutic paradigm that includes hemodynamic resuscitation, hemostatic resuscitation, and homeostatic resuscitation. Definitive control of bleeding is the principal objective of any comprehensive resuscitation scheme for hemorrhagic shock.

Hyperfibrinolysis in severe isolated traumatic brain injury may occur without tissue hypoperfusion: a retrospective observational multicentre study

BACKGROUND

Hyperfibrinolysis is a critical complication in severe trauma. Hyperfibrinolysis is traditionally diagnosed via elevated D-dimer or fibrin/fibrinogen degradation product levels, and recently, using thromboelastometry. Although hyperfibrinolysis is observed in patients with severe isolated traumatic brain injury (TBI) on arrival at the emergency department (ED), it is unclear which factors induce hyperfibrinolysis. The present study aimed to investigate the factors associated with hyperfibrinolysis in patients with isolated severe TBI.

METHODS

We conducted a multicentre retrospective review of data for adult trauma patients with an injury severity score ≥ 16, and selected patients with isolated TBI (TBI group) and extra-cranial trauma (non-TBI group). The TBI group included patients with an abbreviated injury score (AIS) for the head ≥ 4 and an extra-cranial AIS < 2. The non-TBI group included patients with an extra-cranial AIS ≥ 3 and head AIS < 2. Hyperfibrinolysis was defined as a D-dimer level ≥ 38 mg/L on arrival at the ED. We evaluated the relationships between hyperfibrinolysis and injury severity/tissue injury/tissue perfusion in TBI patients by comparing them with non-TBI patients.

RESULTS

We enrolled 111 patients in the TBI group and 126 in the non-TBI group. In both groups, patients with hyperfibrinolysis had more severe injuries and received transfusion more frequently than patients without hyperfibrinolysis. Tissue injury, evaluated on the basis of lactate dehydrogenase and creatine kinase levels, was associated with hyperfibrinolysis in both groups. Among patients with TBI, the mortality rate was higher in those with hyperfibrinolysis than in those without hyperfibrinolysis. Tissue hypoperfusion, evaluated on the basis of lactate level, was associated with hyperfibrinolysis in only the non-TBI group. Although the increase in lactate level was correlated with the deterioration of coagulofibrinolytic variables (prolonged prothrombin time and activated partial thromboplastin time, decreased fibrinogen levels, and increased D-dimer levels) in the non-TBI group, no such correlation was observed in the TBI group.

CONCLUSIONS

Hyperfibrinolysis is associated with tissue injury and trauma severity in TBI and non-TBI patients. However, tissue hypoperfusion is associated with hyperfibrinolysis in non-TBI patients, but not in TBI patients. Tissue hypoperfusion may not be a prerequisite for the occurrence of hyperfibrinolysis in patients with isolated TBI.

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.

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.

Damage control resuscitation

The early recognition and management of hemorrhage shock are among the most difficult tasks challenging the clinician during primary assessment of the acutely bleeding patient. Often with little time, within a chaotic setting, and without sufficient clinical data, a decision must be reached to begin transfusion of blood components in massive amounts. The practice of massive transfusion has advanced considerably and is now a more complete and, arguably, more effective process. This new therapeutic paradigm, referred to as damage control resuscitation (DCR), differs considerably in many important respects from previous management strategies for catastrophic blood loss. We review several important elements of DCR including immediate correction of specific coagulopathies induced by hemorrhage and management of several extreme homeostatic imbalances that may appear in the aftermath of resuscitation. We also emphasize that the foremost objective in managing exsanguinating hemorrhage is always expedient and definitive control of the source of bleeding.

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.

Massive amounts of tissue factor induce fibrinogenolysis without tissue hypoperfusion in rats

Trauma-induced tissue factor (TF) release into the systemic circulation is considered to play an important role in the development of disseminated intravascular coagulation (DIC) immediately after severe trauma. However, the relationship between TF and hyperfibrinolysis, especially fibrinogenolysis, has been unclear. A total of 18 rats were divided into three groups: (a) the control group was infused with normal saline; (b) the low-dose group was infused with 4 U/kg TF; and (c) the high-dose group was infused with 16 U/kg TF. Arterial blood was drawn immediately and 2 and 4 h after the start of TF infusion. At each sampling point, arterial blood gases, platelet counts, and coagulation variables were measured. The fibrinogen degradation products were evaluated by a Western blot analysis. Hypotension, hypoxemia, and lactic acidosis were not observed in any of the three groups. In proportion to the doses of TF, the platelet counts, coagulation, and fibrinolysis variables deteriorated in line with DIC. The α2-plasmin inhibitor levels significantly decreased in the high-dose group compared with the other groups. The amounts of fibrinogen degradation products increased in proportion to the doses of TF. The plasmin-α2-plasmin inhibitor complex level in the high-dose group increased more than that of the other groups. In conclusion, TF can induce DIC associated with fibrinolysis and fibrinogenolysis without tissue hypoperfusion. The decrease in the α2-plasmin inhibitor level and the significant increase in the plasmin level may be the two main factors underlying the pathogenesis of hyperfibrin(ogen)olysis after TF administration.

Pathogenesis of acute traumatic coagulopathy

Acute traumatic coagulopathy (ATC) is an early endogenous process, driven by the combination of tissue injury and shock that is associated with increased mortality and worse outcomes in the polytrauma patient. This review summarizes our current understanding of the pathophysiology of ATC and the role of rapid diagnostics in the management of severe trauma hemorrhage. In particular we consider diagnostic and therapeutic strategies for bleeding trauma patients with short versus long prehospital times and the concept of remote damage control resuscitation. Endothelial activation of Protein C is a central mechanism of ATC, which produces rapid anticoagulation and fibrinolysis following severe trauma. Continued blood loss, hypothermia, acidosis, and hemodilution potentiate ATC and lead to a global derangement in all components of hemostasis. The contribution and interplay between platelet activity, fibrinogen utilization, endothelial dysfunction, and neurohormonal pathways remain to be defined in ATC pathogenesis but may offer novel therapeutic targets. Conventional laboratory-based tests of coagulation have a limited role in the early management of major trauma hemorrhage. TEG and ROTEM provide a rapid evaluation of clot dynamics in whole blood and are of greater value than coagulation screens in diagnosing and managing trauma hemorrhage.

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.

The impact of nontherapeutic hypothermia on outcomes after severe traumatic brain injury

INTRODUCTION

In patients with isolated severe traumatic brain injury (TBI), the effect of controlled, therapeutic hypothermia on outcomes has been studied extensively. What is not well understood, however, and the purpose of this study, was to examine the impact of noninduced, nontherapeutic hypothermia on outcomes in these patients.

METHODS

A retrospective review of the institutional trauma registry at the Los Angeles County + University of Southern California Medical Center was performed to identify all trauma patients admitted to the surgical intensive care unit (SICU) with isolated severe TBI from January 2000 to December 2008. Patients were classified as hypothermic (core temperature [Tc] ≤35°C) or normothermic (Tc >35°C) based on their first Tc recorded on SICU admission. The primary outcome measure was in-hospital mortality, and secondary outcomes included SICU and hospital length of stay.

RESULTS

During the study period, 1,403 patients sustaining an isolated severe TBI were admitted to the SICU. After excluding 122 patients with missing temperature data, 1,281 patients were analyzed. Hypothermia (Tc ≤35°C) on SICU admission was identified in 10.9% (n = 140) of the study population, with the remaining 89.1% (n = 1,141) being normothermic (Tc >35°C). After adjusting for differences in baseline characteristics between the two groups, patients who were hypothermic on SICU admission were found to be significantly less likely to survive (odds ratio, 2.9; 95% confidence interval, 1.3, 6.7; p < 0.013). A penetrating mechanism of injury, Injury Severity Score ≥25, and undergoing an exploratory laparotomy before admission were found to be independent risk factors for the development of hypothermia on SICU admission.

CONCLUSION

For patients who have sustained isolated severe TBI, the presence of noninduced, nontherapeutic hypothermia on SICU admission is associated with a significant increase in mortality. The impact of preventative measures used to avoid the development of hypothermia and the effectiveness of measures for restoring normothermia warrant further investigation.

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.

New insights into acute coagulopathy in trauma patients

Abnormal coagulation parameters can be found in 25% of trauma patients with major injuries. Furthermore, trauma patients presenting with coagulopathy on admission have worse clinical outcome. Tissue trauma and systemic hypoperfusion appear to be the primary factors responsible for the development of acute traumatic coagulopathy immediately after injury. As a result of overt activation of the protein C pathway, the acute traumatic coagulopathy is characterised by coagulopathy in conjunction with hyperfibrinolysis. This coagulopathy can then be exacerbated by subsequent physiologic and physical derangements such as consumption of coagulation factors, haemodilution, hypothermia, acidemia and inflammation, all factors being associated with ongoing haemorrhage and inadequate resuscitation or transfusion therapies. Knowledge of the different mechanisms involved in the pathogenesis of acute traumatic coagulopathy is essential for successful management of bleeding trauma patients. Therefore, early evidence suggests that treatment directed at aggressive and targeted haemostatic resuscitation can lead to reductions in mortality of severely injured patients.

Hemostatic and hemorrhagic problems in neurosurgical patients

BACKGROUND

Abnormalities of the hemostasis can lead to hemorrhage, and on the other hand to thrombosis. Intracranial neoplasms, complex surgical procedures, and head injury have a specific impact on coagulation and fibrinolysis. Moreover, the number of neurosurgical patients on medication (which interferes with platelet function and/or the coagulation systems) has increased over the past years.

METHOD

The objective of this review is to recall common hemostatic disorders in neurosurgical patients on the basis of the "new concept of hemostasis". Therefore the pertinent literature was searched to provide a structured and up to date manuscript about hemostasis in Neurosurgery.

FINDINGS

According to recent scientific publications abnormalities of the coagulation system are discussed. Pathophysiological background and the rational for specific (cost)-effective perioperative hemostatic therapy is provided.

CONCLUSIONS

Perturbations of hemostasis can be multifactorial and maybe encountered in the daily practice of neurosurgery. Early diagnosis and specific treatment is the prerequisite for successful treatment and good patients outcome.

The coagulopathy of trauma: a review of mechanisms

BACKGROUND

Bleeding is the most frequent cause of preventable death after severe injury. Coagulopathy associated with severe injury complicates the control of bleeding and is associated with increased morbidity and mortality in trauma patients. The causes and mechanisms are multiple and yet to be clearly defined.

METHODS

Articles addressing the causes and consequences of trauma-associated coagulopathy were identified and reviewed. Clinical situations in which the various mechanistic causes are important were sought along with quantitative estimates of their importance.

RESULTS

Coagulopathy associated with traumatic injury is the result of multiple independent but interacting mechanisms. Early coagulopathy is driven by shock and requires thrombin generation from tissue injury as an initiator. Initiation of coagulation occurs with activation of anticoagulant and fibrinolytic pathways. This Acute Coagulopathy of Trauma-Shock is altered by subsequent events and medical therapies, in particular acidemia, hypothermia, and dilution. There is significant interplay between all mechanisms.

CONCLUSIONS

There is limited understanding of the mechanisms by which tissue trauma, shock, and inflammation initiate trauma coagulopathy. Acute Coagulopathy of Trauma-Shock should be considered distinct from disseminated intravascular coagulation as described in other conditions. Rapid diagnosis and directed interventions are important areas for future research.

Coagulation disorders after traumatic brain injury

BACKGROUND

Over the past decade new insights in our understanding of coagulation have identified the prominent role of tissue factor. The brain is rich in tissue factor, and injury to the brain may initiate disturbances in local and systemic coagulation. We aimed to review the current knowledge on the pathophysiology, incidence, nature, prognosis and treatment of coagulation disorders following traumatic brain injury (TBI).

METHODS

We performed a MEDLINE search from 1966 to April 2007 with various MESH headings, focusing on head trauma and coagulopathy. We identified 441 eligible English language studies. These were reviewed for relevance by two independent investigators. A meta-analysis was performed to calculate the frequencies of coagulopathy after TBI and to determine the association of coagulopathy and outcome, expressed as odds ratios.

RESULTS

Eighty-two studies were relevant for the purpose of this review. Meta-analysis of 34 studies reporting the frequencies of coagulopathy after TBI, showed an overall prevalence of 32.7%. The presence of coagulopathy after TBI was related both to mortality (OR 9.0; 95%CI: 7.3-11.6) and unfavourable outcome (OR 36.3; 95%CI: 18.7-70.5).

CONCLUSIONS

We conclude that coagulopathy following traumatic brain injury is an important independent risk factor related to prognosis. Routine determination of the coagulation status should therefore be performed in all patients with traumatic brain injury. These data may have important implications in patient management. Well-performed prospective clinical trials should be undertaken as a priority to determine the beneficial effects of early treatment of coagulopathy.

Non-neurologic organ dysfunction in acute brain injury

Patients with acute brain injury are a distinct group within the ICU who may develop non-neurologic organ dysfunction in the absence of systemic injury or infection. This dysfunction may arise directly as a result of the brain injury or indirectly with complications of brain-specific therapies. This article reviews the current literature with respect to the incidence of organ dysfunction or failure and its association with outcome in patients with acute brain injury. Organ system-specific etiologic considerations and management are discussed.

The effect of fresh frozen plasma in severe closed head injury

OBJECTIVE

Traumatic brain injury (TBI) is one of the most common causes of morbidity and mortality. Coagulopathy, commonly occurring after severe TBI, is associated with poor outcome and secondary complications, especially delayed traumatic intracerebral hematoma (DTICH). In this study we evaluated the effect of fresh frozen plasma (FFP) on the reduction in the incidence of DTICH in severe closed head injury victims.

METHODS

This study was carried out as a double-blind randomized clinical trial. Ninety patients were entered in two parallel groups taking either FFP or normal saline (N/S). Patients' selection criteria for both groups were: severe closed head injury (Glasgow coma scale < or =8), no mass lesion required evacuation and no history of coagulopathy. The clinical findings, laboratory data, computed tomography (CT) scans and Glasgow outcome scale after 1 month were assessed and compared in two groups.

RESULTS

Out of 90 patients, 44 received FFP and 46 received N/S. The development of new intracerebral hematoma in follow-up CT scans were more common in the FFP group than the N/S group (p=0.012). Both groups showed similar frequency of poor outcome (p=0.343). The mortality was significantly more common in the FFP group than in the N/S group (63% versus 35%, p=0.006).

CONCLUSION

The result of this study revealed that early empirical infusion of FFP in patients with severe head injury may lead to adverse effects, such as an increase in the frequency of DTICH and an increase in the mortality.

Subsequent Development of Thrombocytopenia and Coagulopathy in Moderate and Severe Head Injury: Support for Serial Laboratory Examination

BACKGROUND

Patients with moderate and severe traumatic brain injury (TBI) are at risk for secondary brain insults such as thrombocytopenia and coagulopathy. This study assessed the development of thrombocytopenia and coagulopathy at admission and within the subsequent 72 hours after TBI.

METHODS

Blunt trauma patients with moderate or severe TBI and an extracranial Abbreviated Injury Scale score less than 3 were reviewed. Data collection included initial and subsequent prothrombin time, partial thromboplastin time, and platelet values.

RESULTS

On initial evaluation, thrombocytopenia was present in 14% and coagulopathy in 21% of patients. By the third day, thrombocytopenia and coagulopathy increased to 46% and 41%, respectively. Of patients who died, 67% had thrombocytopenia and 62% had coagulopathy.

CONCLUSION

Patients with moderate and severe TBI are at risk for thrombocytopenia and coagulopathy, not only at admission but also on subsequent laboratory examination. Repeat laboratory evaluation is warranted even if initial results are normal in this population.