Haemostatic drugs for traumatic brain injury

The recent two decades of traumatic brain injury: a bibliometric analysis and systematic review

BACKGROUND

Traumatic brain injury (TBI) is a serious public health burden worldwide, with a mortality rate of 20-30%; however, reducing the incidence and mortality rates of TBI remains a major challenge. This study provides a multidimensional analysis to explore the potential breakthroughs in TBI over the past two decades.

MATERIALS AND METHODS

The authors used bibliometric and Latent Dirichlet Allocation (LDA) analyses to analyze publications focusing on TBI published between 2003 and 2022 from the Web of Science Core Collection (WOSCC) database to identify core journals and collaborations among countries/regions, institutions, authors, and research trends.

RESULTS

Over the past 20 years, 41 545 articles on TBI from 3043 journals were included, with 12 916 authors from 20 449 institutions across 145 countries/regions. The annual number of publications has increased 10-fold compared to previous publications. This study revealed that high-income countries, especially the United States, have a significant influence. Collaboration was limited to several countries/regions. The LDA results indicated that the hotspots included four main areas: 'Clinical finding', 'Molecular mechanism', 'Epidemiology', and 'Prognosis'. Epidemiological research has consistently increased in recent years. Through epidemiological topic analysis, the main etiology of TBI has shifted from traffic accidents to falls in a demographically aging society.

CONCLUSION

Over the past two decades, TBI research has developed rapidly, and its epidemiology has received increasing attention. Reducing the incidence of TBI from a preventive perspective is emerging as a trend to alleviate the future social burden; therefore, epidemiological research might bring breakthroughs in TBI.

Systemic hemostatic agents initiated in trauma patients in the pre-hospital setting: a systematic review

Purpose

The effect of systemic hemostatic agents initiated during pre-hospital care of severely injured patients with ongoing bleeding or traumatic brain injury (TBI) remains controversial. A systematic review and meta-analysis was therefore conducted to assess the effectiveness and safety of systemic hemostatic agents as an adjunctive therapy in people with major trauma and hemorrhage or TBI in the context of developing the Italian National Institute of Health guidelines on major trauma integrated management.

Methods

PubMed, Embase, and Cochrane Library databases were searched up to October 2021 for studies that investigated pre-hospital initiated treatment with systemic hemostatic agents. The certainty of evidence was evaluated with the Grading of Recommendations Assessment, Development, and Evaluation approach, and the quality of each study was determined with the Cochrane risk-of-bias tool. The primary outcome was overall mortality, and secondary outcomes included cause-specific mortality, health-related quality of life, any adverse effects and blood product use, hemorrhage expansion, and patient-reported outcomes.

Results

Five trials of tranexamic acid (TXA) met the inclusion criteria for this meta-analysis. With a high certainty of evidence, when compared to placebo TXA reduced mortality at 24 h (relative risk = 0.83, 95% confidence interval = 0.73–0.94) and at 1 month among trauma patients (0.91, 0.85–0.97). These results depend on the subgroup of patients with significant hemorrhage because in the subgroup of TBI there are no difference between TXA and placebo. TXA also reduced bleeding death and multiple organ failure whereas no difference in health-related quality of life.

Conclusion

Balancing benefits and harms, TXA initiated in the pre-hospital setting can be used for patients experiencing major trauma with significant hemorrhage since it reduces the risk of mortality at 24 h and one month with no difference in terms of adverse effects when compared to placebo. Considering the subgroup of severe TBI, no difference in mortality rate was found at 24 h and one month. These results highlight the need to conduct future studies to investigate the role of other systemic hemostatic agents in the pre-hospital settings.

The currency, completeness and quality of systematic reviews of acute management of moderate to severe traumatic brain injury: A comprehensive evidence map

OBJECTIVE

To appraise the currency, completeness and quality of evidence from systematic reviews (SRs) of acute management of moderate to severe traumatic brain injury (TBI).

METHODS

We conducted comprehensive searches to March 2016 for published, English-language SRs and RCTs of acute management of moderate to severe TBI. Systematic reviews and RCTs were grouped under 12 broad intervention categories. For each review, we mapped the included and non-included RCTs, noting the reasons why RCTs were omitted. An SR was judged as 'current' when it included the most recently published RCT we found on their topic, and 'complete' when it included every RCT we found that met its inclusion criteria, taking account of when the review was conducted. Quality was assessed using the AMSTAR checklist (trichotomised into low, moderate and high quality).

FINDINGS

We included 85 SRs and 213 RCTs examining the effectiveness of treatments for acute management of moderate to severe TBI. The most frequently reviewed interventions were hypothermia (n = 17, 14.2%), hypertonic saline and/or mannitol (n = 9, 7.5%) and surgery (n = 8, 6.7%). Of the 80 single-intervention SRs, approximately half (n = 44, 55%) were judged as current and two-thirds (n = 52, 65.0%) as complete. When considering only the most recently published review on each intervention (n = 25), currency increased to 72.0% (n = 18). Less than half of the 85 SRs were judged as high quality (n = 38, 44.7%), and nearly 20% were low quality (n = 16, 18.8%). Only 16 (20.0%) of the single-intervention reviews (and none of the five multi-intervention reviews) were judged as current, complete and high-quality. These included reviews of red blood cell transfusion, hypothermia, management guided by intracranial pressure, pharmacological agents (various) and prehospital intubation. Over three-quarters (n = 167, 78.4%) of the 213 RCTs were included in one or more SR. Of the remainder, 17 (8.0%) RCTs post-dated or were out of scope of existing SRs, and 29 (13.6%) were on interventions that have not been assessed in SRs.

CONCLUSION

A substantial number of SRs in acute management of moderate to severe TBI lack currency, completeness and quality. We have identified both potential evidence gaps and also substantial research waste. Novel review methods, such as Living Systematic Reviews, may ameliorate these shortcomings and enhance utility and reliability of the evidence underpinning clinical care.

Coagulopathy and haemorrhagic progression in traumatic brain injury: advances in mechanisms, diagnosis, and management

Normal haemostasis depends on an intricate balance between mechanisms of bleeding and mechanisms of thrombosis, and this balance can be altered after traumatic brain injury (TBI). Impaired haemostasis could exacerbate the primary insult with risk of initiation or aggravation of bleeding; anticoagulant use at the time of injury can also contribute to bleeding risk after TBI. Many patients with TBI have abnormalities on conventional coagulation tests at admission to the emergency department, and the presence of coagulopathy is associated with increased morbidity and mortality. Further blood testing often reveals a range of changes affecting platelet numbers and function, procoagulant or anticoagulant factors, fibrinolysis, and interactions between the coagulation system and the vascular endothelium, brain tissue, inflammatory mechanisms, and blood flow dynamics. However, the degree to which these coagulation abnormalities affect TBI outcomes and whether they are modifiable risk factors are not known. Although the main challenge for management is to address the risk of hypocoagulopathy with prolonged bleeding and progression of haemorrhagic lesions, the risk of hypercoagulopathy with an increased prothrombotic tendency also warrants consideration.

Pharmacological interventions in traumatic brain injury: Can we rely on systematic reviews for evidence?

INTRODUCTION

Providing current, reliable and evidence based information for clinicians and researchers in a synthesised and summarised way can be challenging particularly in the area of traumatic brain injury where a vast number of reviews exists. These reviews vary in their methodological quality and are scattered across varying sources. In this paper, we present an overview of systematic reviews that evaluate the pharmacological interventions in traumatic brain injury (TBI). By doing this, we aim to evaluate the existing evidence for improved outcomes in TBI with pharmacological interventions, and to identify gaps in the literature to inform future research.

METHODS

We searched the Neurotrauma Evidence Map on systematic reviews relating to pharmacological interventions for managing TBI in acute phase. Two reviewers independently screened search results and appraised each systematic review using the validated AMSTAR tool and extracted data from the review.

RESULTS

A total of 288 systematic reviews relating to TBI were available on the Neurotrauma Evidence Map at the time of this study. We identified 19 systematic reviews on pharmacological management for acute TBI with publications dates ranging from 1998 to 2014. The studies were of varying methodological quality, with a mean AMSTAR score of 7.78 (range 2-11].

CONCLUSION

The evidence from high quality systematic reviews show that there is currently insufficient evidence for the use of magnesium, monoaminergic and dopamine agonists, progesterone, aminosteroids, excitatory amino acid inhibitors, haemostatic and antifibrinolytic drugs in TBI. Anti-convulsants are only effective in reducing early seizures with no significant difference between phenytoin and leviteracetam. There is no difference between propofol and midazolam for sedation in TBI patients and ketamine may not cause increased ICP. Overviews of systematic review provide informative and powerful summaries of evidence based research.

Coagulation Parameters and Risk of Progressive Hemorrhagic Injury after Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Intracranial hemorrhage (ICH) after traumatic brain injury (TBI) commonly increases in size and coagulopathy has been implicated in such progression. Our aim is to perform a meta-analysis to assess their relationship. Cochrane library, PubMed, and EMBASE were searched for literatures. Pooled effect sizes and 95% confidential intervals (CIs) were calculated using random-effects model. We included six studies, involving 1700 participants with 540 progressive hemorrhagic injuries (PHIs). Our findings indicate that PT, D-dimer level, and INR value are positively associated with the risk of PHI. Higher level of PLT and Fg seemed to suggest a lower risk of PHI. Among these parameters, higher D-dimer level and INR value would possess more powerful strength in predicting PHI.

Antifibrinolytic drugs for acute traumatic injury

BACKGROUND

Uncontrolled bleeding is an important cause of death in trauma victims. Antifibrinolytic treatment has been shown to reduce blood loss following surgery and may also be effective in reducing blood loss following trauma.

OBJECTIVES

To assess the effect of antifibrinolytic drugs in patients with acute traumatic injury.

SEARCH METHODS

We ran the most recent search in January 2015. We searched the Cochrane Injuries Group's Specialised Register, The Cochrane Library, Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic+Embase (OvidSP), PubMed and clinical trials registries.

SELECTION CRITERIA

Randomised controlled trials of antifibrinolytic agents (aprotinin, tranexamic acid [TXA], epsilon-aminocaproic acid and aminomethylbenzoic acid) following acute traumatic injury.

DATA COLLECTION AND ANALYSIS

From the results of the screened electronic searches, bibliographic searches, and contacts with experts, two authors independently selected trials meeting the inclusion criteria, and extracted data. One review author assessed the risk of bias for key domains.Outcome measures included: mortality at end of follow-up (all-cause); adverse events (specifically vascular occlusive events [myocardial infarction, stroke, deep vein thrombosis or pulmonary embolism] and renal failure); number of patients undergoing surgical intervention or receiving blood transfusion; volume of blood transfused; volume of intracranial bleeding; brain ischaemic lesions; death or disability.We rated the quality of the evidence as 'high', 'moderate', 'low' or 'very low' according to the GRADE approach.

MAIN RESULTS

Three trials met the inclusion criteria.Two trials (n = 20,451) assessed the effect of TXA. The larger of these (CRASH-2, n = 20,211) was conducted in 40 countries and included patients with a variety of types of trauma; the other (n = 240) restricted itself to those with traumatic brain injury (TBI) only.One trial (n = 77) assessed aprotinin in participants with major bony trauma and shock.The pooled data show that antifibrinolytic drugs reduce the risk of death from any cause by 10% (RR 0.90, 95% CI 0.85 to 0.96; P = 0.002) (quality of evidence: high). This estimate is based primarily on data from the CRASH-2 trial of TXA, which contributed 99% of the data.There is no evidence that antifibrinolytics have an effect on the risk of vascular occlusive events (quality of evidence: moderate), need for surgical intervention or receipt of blood transfusion (quality of evidence: high). There is no evidence for a difference in the effect by type of antifibrinolytic (TXA versus aprotinin) however, as the pooled analyses were based predominantly on trial data concerning the effects of TXA, the results can only be confidently applied to the effects of TXA. The effects of aprotinin in this patient group remain uncertain.There is some evidence from pooling data from one study (n = 240) and a subset of data from CRASH-2 (n = 270) in patients with TBI which suggest that TXA may reduce mortality although the estimates are imprecise, the quality of evidence is low, and uncertainty remains. Stronger evidence exists for the possibility of TXA reducing intracranial bleeding in this population.

AUTHORS' CONCLUSIONS

TXA safely reduces mortality in trauma patients with bleeding without increasing the risk of adverse events.  TXA should be given as early as possible and within three hours of injury, as further analysis of the CRASH-2 trial showed that treatment later than this is unlikely to be effective and may be harmful. Although there is some promising evidence for the effect of TXA in patients with TBI, substantial uncertainty remains.Two ongoing trials being conducted in patients with isolated TBI should resolve these remaining uncertainties.

Factors prognosticating the outcome of decompressive craniectomy in severe traumatic brain injury: A Malaysian experience

Objective:

The objective of this prospective cohort study was to analyse the characteristics of severe Traumatic Brain Injury (TBI) in a regional trauma centre Hospital Kuala Lumpur (HKL) along with its impact of various prognostic factors post Decompressive Craniectomy (DC).

Materials and Methods:

Duration of the study was of 13 months in HKL. 110 consecutive patients undergoing DC and remained in our centre were recruited. They were then analysed categorically with standard analytical software.

Results:

Age group have highest range between 12-30 category with male preponderance. Common mechanism of injury was motor vehicle accident involving motorcyclist. Univariate analysis showed statistically significant in referral area (P = 0.006). In clinical evaluation statistically significant was the motor score (P = 0.040), pupillary state (P = 0.010), blood pressure stability (P = 0.013) and evidence of Diabetes Insipidus (P < 0.001). In biochemical status the significant statistics included evidence of coagulopathy (P < 0.001), evidence of acidosis (P = 0.003) and evidence of hypoxia (P = 0.030). In Radiological sector, significant univariate analysis proved in location of the subdural clot (P < 0.010), location of the contusion (P = 0.045), site of existence of both type of clots (P = 0.031) and the evidence of edema (P = 0.041). The timing of injury was noted to be significant as well (P = 0.061). In the post operative care was, there were significance in the overall stability in intensive care (P < 0.001), the stability of blood pressure, cerebral perfusion pressure, pulse rates and oxygen saturation (all P < 0.001)seen individually, post operative ICP monitoring in the immediate (P = 0.002), within 24 hours (P < 0.001) and within 24-48 hours (P < 0.001) period, along with post operative pupillary size (P < 0.001) and motor score (P < 0.001). Post operatively, radiologically significant statistics included evidence of midline shift post operatively in the CT scan (P < 0.001). Multivariate logistic regression with stepwise likelihood ratio (LR) method concluded that hypoxia post operatively (P = 0.152), the unmaintained Cerebral Perfusion Pressure (CPP) (P = 0.007) and unstable blood pressure (BP) (P = <0.001). Poor outcome noted 10.2 times higher in post operative hypoxia [OR10.184; 95% CI: 0.424, 244.495]. Odds of having poor outcome if CPP unmaintained was 13.8 times higher [OR: 13.754; CI: 2.050, 92.301]. Highest predictor of poor outcome was the unstable BP, 32 times higher [OR 31.600; CI: 4.530, 220440].

Conclusion:

Our series represent both urban and rural population, noted to be the largest series in severe TBI in this region. Severe head injury accounts for significant proportion of neurosurgical admissions, resources with its impact on socio-economic concerns to a growing population like Malaysia. This study concludes that the predictors of outcome in severe TBI post DC were postoperative hypoxia, unmaintained cerebral perfusion pressure and unstable blood pressure as independent predictors of poor outcome. Key words: Decompressive craniectomy, prognostication of decompressive craniectomy, prognostication of severe head injury, prognostication of traumatic brain injury, severe head injury, severe traumatic brain injury, traumatic brain injury.

Tranexamic acid for patients with traumatic brain injury: a randomized, double-blinded, placebo-controlled trial

BACKGROUND

Traumatic brain injury (TBI) is commonly accompanied by intracranial bleeding which can worsen after hospital admission. Tranexamic acid (TXA) has been shown to reduce bleeding in elective surgery and there is evidence that short courses of TXA can reduce rebleeding in spontaneous intracranial haemorrhage. We aimed to determine the effectiveness and safety of TXA in preventing progressive intracranial haemorrhage in TBI.

METHODS

This is a double blinded, placebo controlled randomized trial. We enrolled 238 patients older than 16 years with moderate to severe TBI (post-resuscitation Glasgow Coma Scale (GCS) 4 to 12) who had a computerized tomography (CT) brain scan within eight hours of injury and in whom there was no immediate indication for surgery. We excluded patients if they had a coagulopathy or a serum creatinine over than 2.0 milligrams%. The treatment was a single dose of 2 grams of TXA in addition to other standard treatments. The primary outcome was progressive intracranial haemorrhage (PIH) which was defined as an intracranial haemorrhage seen on the second CT scan that was not seen on the first CT scan, or an intracranial haemorrhage seen on the first scan that had expanded by 25% or more on any dimension (height, length, or width) on the second scan.

RESULTS

Progressive intracranial haemorrhage was present in 21 (18%) of 120 patients allocated to TXA and in 32 (27%) of 118 patients allocated to placebo. The difference was not statistically significant [RR = 0.65 (95% CI 0.40 to 1.05)]. There were no significant difference in the risk of death from all causes in patients allocated to TXA compared with placebo [RR = 0.69 (95% CI 0.35 to 1.39)] and the risk of unfavourable outcome on the Glasgow Outcome Scale [RR = 0.76 (95% CI 0.46 to 1.27)]. There was no evidence of increased risk of thromboembolic events in those patients allocated to TXA.

CONCLUSIONS

TXA may reduce PIH in patients with TBI; however, the difference was not statistically significant in this trial. Large clinical trials are needed to confirm and to assess the effect of TXA on death or disability after TBI.

Perioperative management of traumatic brain injury

Traumatic brain injury (TBI) is a major public health problem and the leading cause of death and disability worldwide. Despite the modern diagnosis and treatment, the prognosis for patients with TBI remains poor. While severity of primary injury is the major factor determining the outcomes, the secondary injury caused by physiological insults such as hypotension, hypoxemia, hypercarbia, hypocarbia, hyperglycemia and hypoglycemia, etc. that develop over time after the onset of the initial injury, causes further damage to brain tissue, worsening the outcome in TBI. Perioperative period may be particularly important in the course of TBI management. While surgery and anesthesia may predispose the patients to new onset secondary injuries which may contribute adversely to outcomes, the perioperative period is also an opportunity to detect and correct the undiagnosed pre-existing secondary insults, to prevent against new secondary insults and is a potential window to initiate interventions that may improve outcome of TBI. For this review, extensive Pubmed and Medline search on various aspects of perioperative management of TBI was performed, followed by review of research focusing on intraoperative and perioperative period. While the research focusing specifically on the intraoperative and immediate perioperative TBI management is limited, clinical management continues to be based largely on physiological optimization and recommendations of Brain Trauma Foundation guidelines. This review is focused on the perioperative management of TBI, with particular emphasis on recent developments.

Management of bleeding and coagulopathy following major trauma: an updated European guideline

INTRODUCTION

Evidence-based recommendations are needed to guide the acute management of the bleeding trauma patient. When these recommendations are implemented patient outcomes may be improved.

METHODS

The multidisciplinary Task Force for Advanced Bleeding Care in Trauma was formed in 2005 with the aim of developing a guideline for the management of bleeding following severe injury. This document represents an updated version of the guideline published by the group in 2007 and updated in 2010. Recommendations were formulated using a nominal group process, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) hierarchy of evidence and based on a systematic review of published literature.

RESULTS

Key changes encompassed in this version of the guideline include new recommendations on the appropriate use of vasopressors and inotropic agents, and reflect an awareness of the growing number of patients in the population at large treated with antiplatelet agents and/or oral anticoagulants. The current guideline also includes recommendations and a discussion of thromboprophylactic strategies for all patients following traumatic injury. The most significant addition is a new section that discusses the need for every institution to develop, implement and adhere to an evidence-based clinical protocol to manage traumatically injured patients. The remaining recommendations have been re-evaluated and graded based on literature published since the last edition of the guideline. Consideration was also given to changes in clinical practice that have taken place during this time period as a result of both new evidence and changes in the general availability of relevant agents and technologies.

CONCLUSIONS

A comprehensive, multidisciplinary approach to trauma care and mechanisms with which to ensure that established protocols are consistently implemented will ensure a uniform and high standard of care across Europe and beyond.

Perioperative management of adult traumatic brain injury

This article presents an overview of the management of traumatic brain injury (TBI) as relevant to the practicing anesthesiologist. Key concepts surrounding the pathophysiology and anesthetic principles are used to describe potential ways to reduce secondary insults and improve outcomes after TBI.

Recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia

BACKGROUND

Recombinant factor VIIa (rFVIIa) is licensed for use in patients with haemophilia and inhibitory allo-antibodies and for prophylaxis and treatment of patients with congenital factor VII deficiency. It is also used for off-license indications to prevent bleeding in operations where blood loss is likely to be high, and/or to stop bleeding that is proving difficult to control by other means. This is the third version of the 2007 Cochrane review on the use of recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia, and has been updated to incorporate recent trial data.

OBJECTIVES

To assess the effectiveness of rFVIIa when used therapeutically to control active bleeding or prophylactically to prevent (excessive) bleeding in patients without haemophilia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and other medical databases up to 23 March 2011.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing rFVIIa with placebo, or one dose of rFVIIa with another, in any patient population (except haemophilia). Outcomes were mortality, blood loss or control of bleeding, red cell transfusion requirements, number of patients transfused and thromboembolic adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed potentially relevant studies for inclusion, extracted data and examined risk of bias. We considered prophylactic and therapeutic rFVIIa studies separately.

MAIN RESULTS

Twenty-nine RCTs were included: 28 were placebo-controlled, double-blind RCTs and one compared different doses of rFVIIa. In the 'Risk of bias' assessment, most studies were found to have some threats to validity although therapeutic RCTs were found to be less prone to bias than prophylactic RCTs.Sixteen trials involving 1361 participants examined the prophylactic use of rFVIIa; 729 received rFVIIa. There was no evidence of mortality benefit (risk ratio (RR) 1.04; 95% confidence interval (CI) 0.55 to 1.97). There was decreased blood loss (mean difference (MD) -297 mL; 95% CI -416 to -178) and decreased red cell transfusion requirements (MD -261 mL; 95% CI -367 to -154) with rFVIIa treatment; however, these values were likely overestimated due to the inability to incorporate data from trials (four RCTs in the outcome of blood loss and three RCTs in the outcome of transfusion requirements) showing no difference of rFVIIa treatment compared to placebo. There was a trend in favour of rFVIIa in the number of participants transfused (RR 0.85; 95% CI 0.72 to 1.01). However, there was a trend against rFVIIa with respect to thromboembolic adverse events (RR 1.35; 95% CI 0.82 to 2.25).Thirteen trials involving 2929 participants examined the therapeutic use of rFVIIa; 1878 received rFVIIa. There were no outcomes where any observed advantage or disadvantage of rFVIIa over placebo could not have been observed by chance alone. There was a trend in favour of rFVIIa for reducing mortality (RR 0.91; 95% CI 0.78 to 1.06). However, there was a trend against rFVIIa for increased thromboembolic adverse events (RR 1.14; 95% CI 0.89 to 1.47).When all trials were pooled together to examine the risk of thromboembolic events, a significant increase in total arterial events was observed (RR 1.45; 95% CI 1.02 to 2.05).

AUTHORS' CONCLUSIONS

The effectiveness of rFVIIa as a more general haemostatic drug, either prophylactically or therapeutically, remains unproven. The results indicate increased risk of arterial events in patients receiving rFVIIa. The use of rFVIIa outside its current licensed indications should be restricted to clinical trials.

Hemorrhagic progression of a contusion after traumatic brain injury: a review

The magnitude of damage to cerebral tissues following head trauma is determined by the primary injury, caused by the kinetic energy delivered at the time of impact, plus numerous secondary injury responses that almost inevitably worsen the primary injury. When head trauma results in a cerebral contusion, the hemorrhagic lesion often progresses during the first several hours after impact, either expanding or developing new, non-contiguous hemorrhagic lesions, a phenomenon termed hemorrhagic progression of a contusion (HPC). Because a hemorrhagic contusion marks tissues with essentially total unrecoverable loss of function, and because blood is one of the most toxic substances to which the brain can be exposed, HPC is one of the most severe types of secondary injury encountered following traumatic brain injury (TBI). Historically, HPC has been attributed to continued bleeding of microvessels fractured at the time of primary injury. This concept has given rise to the notion that continued bleeding might be due to overt or latent coagulopathy, prompting attempts to normalize coagulation with agents such as recombinant factor VIIa. Recently, a novel mechanism was postulated to account for HPC that involves delayed, progressive microvascular failure initiated by the impact. Here we review the topic of HPC, we examine data relevant to the concept of a coagulopathy, and we detail emerging data elucidating the mechanism of progressive microvascular failure that predisposes to HPC after head trauma.

Effect of tranexamic acid in traumatic brain injury: a nested randomised, placebo controlled trial (CRASH-2 Intracranial Bleeding Study)

OBJECTIVE

To assess the effect of tranexamic acid (which reduces bleeding in surgical patients and reduces mortality due to bleeding in trauma patients) on intracranial haemorrhage in patients with traumatic brain injury.

METHODS

A nested, randomised, placebo controlled trial. All investigators were masked to treatment allocation. All analyses were by intention to treat. Patients 270 adult trauma patients with, or at risk of, significant extracranial bleeding within 8 hours of injury, who also had traumatic brain injury.

INTERVENTIONS

Patients randomly allocated to tranexamic acid (loading dose 1 g over 10 minutes, then infusion of 1 g over 8 hours) or matching placebo.

MAIN OUTCOME MEASURES

Intracranial haemorrhage growth (measured by computed tomography) between hospital admission and then 24-48 hours later, with adjustment for Glasgow coma score, age, time from injury to the scans, and initial haemorrhage volume.

RESULTS

Of the 133 patients allocated to tranexamic acid and 137 allocated to placebo, 123 (92%) and 126 (92%) respectively provided information on the primary outcome. All patients provided information on clinical outcomes. The mean total haemorrhage growth was 5.9 ml (SD 26.8) and 8.1 mL (SD 29.2) in the tranexamic acid and placebo groups respectively (adjusted difference -3.8 mL (95% confidence interval -11.5 to 3.9)). New focal cerebral ischaemic lesions occurred in 6 (5%) patients in the tranexamic acid group versus 12 (9%) in the placebo group (adjusted odds ratio 0.51 (95% confidence interval 0.18 to 1.44)). There were 14 (11%) deaths in the tranexamic acid group and 24 (18%) in the placebo group (adjusted odds ratio 0.47 (0.21 to 1.04)).

CONCLUSIONS

This trial shows that neither moderate benefits nor moderate harmful effects of tranexamic acid in patients with traumatic brain injury can be excluded. However, the analysis provides grounds for further clinical trials evaluating the effect of tranexamic acid in this population. Trial registration ISRCTN86750102.

Systematic review: benefits and harms of in-hospital use of recombinant factor VIIa for off-label indications

BACKGROUND

Recombinant factor VIIa (rFVIIa), a hemostatic agent approved for hemophilia, is increasingly used for off-label indications.

PURPOSE

To evaluate the benefits and harms of rFVIIa use for 5 off-label, in-hospital indications: intracranial hemorrhage, cardiac surgery, trauma, liver transplantation, and prostatectomy.

DATA SOURCES

Ten databases (including PubMed, EMBASE, and the Cochrane Library) queried from inception through December 2010. Articles published in English were analyzed.

STUDY SELECTION

Two reviewers independently screened titles and abstracts to identify clinical use of rFVIIa for the selected indications and identified all randomized, controlled trials (RCTs) and observational studies for full-text review.

DATA EXTRACTION

Two reviewers independently assessed study characteristics and rated study quality and indication-wide strength of evidence.

DATA SYNTHESIS

16 RCTs, 26 comparative observational studies, and 22 noncomparative observational studies met inclusion criteria. Identified comparators were limited to placebo (RCTs) or usual care (observational studies). For intracranial hemorrhage, mortality was not improved with rFVIIa use across a range of doses. Arterial thromboembolism was increased with medium-dose rFVIIa use (risk difference [RD], 0.03 [95% CI, 0.01 to 0.06]) and high-dose rFVIIa use (RD, 0.06 [CI, 0.01 to 0.11]). For adult cardiac surgery, there was no mortality difference, but there was an increased risk for thromboembolism (RD, 0.05 [CI, 0.01 to 0.10]) with rFVIIa. For body trauma, there were no differences in mortality or thromboembolism, but there was a reduced risk for the acute respiratory distress syndrome (RD, -0.05 [CI, -0.02 to -0.08]). Mortality was higher in observational studies than in RCTs.

LIMITATIONS

The amount and strength of evidence were low for most outcomes and indications. Publication bias could not be excluded.

CONCLUSION

Limited available evidence for 5 off-label indications suggests no mortality reduction with rFVIIa use. For some indications, it increases thromboembolism.

Systematic review: benefits and harms of in-hospital use of recombinant factor VIIa for off-label indications

BACKGROUND

Recombinant factor VIIa (rFVIIa), a hemostatic agent approved for hemophilia, is increasingly used for off-label indications.

PURPOSE

To evaluate the benefits and harms of rFVIIa use for 5 off-label, in-hospital indications: intracranial hemorrhage, cardiac surgery, trauma, liver transplantation, and prostatectomy.

DATA SOURCES

Ten databases (including PubMed, EMBASE, and the Cochrane Library) queried from inception through December 2010. Articles published in English were analyzed.

STUDY SELECTION

Two reviewers independently screened titles and abstracts to identify clinical use of rFVIIa for the selected indications and identified all randomized, controlled trials (RCTs) and observational studies for full-text review.

DATA EXTRACTION

Two reviewers independently assessed study characteristics and rated study quality and indication-wide strength of evidence.

DATA SYNTHESIS

16 RCTs, 26 comparative observational studies, and 22 noncomparative observational studies met inclusion criteria. Identified comparators were limited to placebo (RCTs) or usual care (observational studies). For intracranial hemorrhage, mortality was not improved with rFVIIa use across a range of doses. Arterial thromboembolism was increased with medium-dose rFVIIa use (risk difference [RD], 0.03 [95% CI, 0.01 to 0.06]) and high-dose rFVIIa use (RD, 0.06 [CI, 0.01 to 0.11]). For adult cardiac surgery, there was no mortality difference, but there was an increased risk for thromboembolism (RD, 0.05 [CI, 0.01 to 0.10]) with rFVIIa. For body trauma, there were no differences in mortality or thromboembolism, but there was a reduced risk for the acute respiratory distress syndrome (RD, -0.05 [CI, -0.02 to -0.08]). Mortality was higher in observational studies than in RCTs.

LIMITATIONS

The amount and strength of evidence were low for most outcomes and indications. Publication bias could not be excluded.

CONCLUSION

Limited available evidence for 5 off-label indications suggests no mortality reduction with rFVIIa use. For some indications, it increases thromboembolism.