CRASH-2 Study of Tranexamic Acid to Treat Bleeding in Trauma Patients: A Controversy Fueled by Science and Social Media

Medullary cavity application of tranexamic acid to reduce blood loss in tibial intramedullary nailing procedures-a randomized controlled trial

PURPOSE

Studies have shown an average postoperative hidden blood loss (HBL) of 473.29 ml and an average Hb loss of 16.71 g/l after intramedullary nailing. Reducing HBL has become a primary consideration for orthopaedic surgeons.

METHODS

Patients with only tibial stem fractures who visited the study clinic between December 2019 and February 2022 were randomized into two groups using a computer-generated form. Two grams of tranexamic acid (TXA) (20 ml) or 20 ml of saline was injected into the medullary cavity before implantation of the intramedullary nail. On the morning of the surgery, as well as on days one, three and five after surgery, routine blood tests and analyses of CRP and interleukin-6 were completed. The primary outcomes were total blood loss (TBL), HBL, and blood transfusion, in which the TBL and HBL were calculated according to the Gross equation and the Nadler equation. Three months after surgery, the incidence of wound complications and thrombotic events, including deep vein thrombosis and pulmonary embolism, was recorded.

RESULTS

Ninety-seven patients (47 in the TXA group and 50 in the NS group) were analyzed; the TBL (252.10 ± 10.05 ml) and HBL (202.67 ± 11.86 ml) in the TXA group were significantly lower than the TBL (417.03 ± 14.60 ml) and HBL (373.85 ± 23.70 ml) in the NS group (p < 0.05). At the three month postoperative follow-up, two patients (4.25%) in the TXA group and three patients (6.00%) in the NS group developed deep vein thrombosis, with no significant difference in the incidence of thrombotic complications (p = 0.944). No postoperative deaths or wound complications occurred in either group.

CONCLUSIONS

The combination of intravenous and topical TXA reduces blood loss after intramedullary nailing of tibial fractures without increasing the incidence of thrombotic events.

Effectiveness and Adverse Effects of Tranexamic Acid in Bleeding during Adenotonsillectomy: A Randomized, Controlled, Double-blind Clinical Trial

Introduction  Intra and postoperative bleeding are the most frequent and feared complications in adenotonsillectomy (AT). Tranexamic acid (TXA), which is known for its antifibrinolytic effects, has a proven benefit in reducing bleeding in hemorrhagic trauma and cardiac surgery; however, the effectiveness and timing of its application in AT have not yet been established.

Objectives  We aimed to evaluate the efficacy of TXA in controlling bleeding during and after AT and assess its possible adverse effects in children.

Methods  The present randomized, controlled, double-blind clinical trial included 63 children aged 2 to 12 years. They were randomly assigned to receive either intravenous TXA (10 mg/kg) or placebo 10 minutes before surgery. The volume of intraoperative bleeding, presence of postoperative bleeding, and adverse effects during and 8 hours after the surgery were assessed.

Results  No difference in bleeding volume was noted between the 2 groups (mean, 122.7 ml in the TXA group versus 115.5 ml in the placebo group, p  = 0.36). No intraoperative or postoperative adverse effects were noted because of TXA use. Furthermore, no primary or secondary postoperative bleeding was observed in any of the participants.

Conclusion  In our pediatric sample, TXA (10 mg/kg) administration before AT was safely used, without any adverse effects. It did not reduce the bleeding volume in children during this type of surgery. Future studies should assess the use of higher doses of TXA and its administration at other time points before or during surgery.

The Pathophysiology and Management of Hemorrhagic Shock in the Polytrauma Patient

The recognition and management of life-threatening hemorrhage in the polytrauma patient poses several challenges to prehospital rescue personnel and hospital providers. First, identification of acute blood loss and the magnitude of lost volume after torso injury may not be readily apparent in the field. Because of the expression of highly effective physiological mechanisms that compensate for a sudden decrease in circulatory volume, a polytrauma patient with a significant blood loss may appear normal during examination by first responders. Consequently, for every polytrauma victim with a significant mechanism of injury we assume substantial blood loss has occurred and life-threatening hemorrhage is progressing until we can prove the contrary. Second, a decision to begin damage control resuscitation (DCR), a costly, highly complex, and potentially dangerous intervention must often be reached with little time and without sufficient clinical information about the intended recipient. Whether to begin DCR in the prehospital phase remains controversial. Furthermore, DCR executed imperfectly has the potential to worsen serious derangements including acidosis, coagulopathy, and profound homeostatic imbalances that DCR is designed to correct. Additionally, transfusion of large amounts of homologous blood during DCR potentially disrupts immune and inflammatory systems, which may induce severe systemic autoinflammatory disease in the aftermath of DCR. Third, controversy remains over the composition of components that are transfused during DCR. For practical reasons, unmatched liquid plasma or freeze-dried plasma is transfused now more commonly than ABO-matched fresh frozen plasma. Low-titer type O whole blood may prove safer than red cell components, although maintaining an inventory of whole blood for possible massive transfusion during DCR creates significant challenges for blood banks. Lastly, as the primary principle of management of life-threatening hemorrhage is surgical or angiographic control of bleeding, DCR must not eclipse these definitive interventions.

Viscoelastic Hemostatic Assays for Postpartum Hemorrhage

This article discusses the importance and effectiveness of viscoelastic hemostatic assays (VHAs) in assessing hemostatic competence and guiding blood component therapy (BCT) in patients with postpartum hemorrhage (PPH). In recent years, VHAs such as thromboelastography and rotational thromboelastometry have increasingly been used to guide BCT, hemostatic adjunctive therapy and prohemostatic agents in PPH. The three pillars of identifying hemostatic competence include clinical observation, common coagulation tests, and VHAs. VHAs are advantageous because they assess the cumulative contribution of all components of the blood throughout the entire formation of a clot, have fast turnaround times, and are point-of-care tests that can be followed serially. Despite these advantages, VHAs are underused due to poor understanding of correct technique and result interpretation, a paucity of widespread standardization, and a lack of large clinical trials. These VHAs can also be used in cases of uterine atony, preeclampsia, acute fatty liver of pregnancy, amniotic fluid embolism, placental abruption, genital tract trauma, surgical trauma, and inherited and prepartum acquired coagulopathies. There exists an immediate need for a point-of-care test that can equip obstetricians with rapid results on developing coagulopathic states. The use of VHAs in predicting and treating PPH, although in an incipient state, can fulfill this need.

[Tranexamic acid for bleeding prophylaxis in orthopedic surgery and trauma-standard or customized therapy?]

The use of tranexamic acid (TXA) is established in the treatment of bleeding, especially of bleeding due to hyperfibrinolysis. In recent years the prophylactic use of TXA in trauma and orthopedic surgery has increased leading to open questions regarding potentially associated risks and a possible classification as off label use. The available literature provides a sound basis for the recommendation that TXA can be used in these indications provided that an individual risk assessment is done in patients with increased risks for thromboembolic complications. Although the prophylactic use of TXA in orthopedic surgery and trauma is not explicitly listed in the product characteristics, it should not be regarded as an off label use.

Safety and efficacy of tranexamic acid in minimizing perioperative bleeding in extrahepatic abdominal surgery: meta-analysis

BACKGROUND

Perioperative bleeding is associated with increased morbidity and mortality in patients undergoing elective abdominal surgery. The antifibrinolytic agent tranexamic acid (TXA) has been shown to reduce perioperative bleeding and mortality risk in patients with traumatic injuries, but there is a lack of evidence for its use in elective abdominal and pelvic surgery. This meta-analysis of RCTs evaluated the effectiveness and safety of TXA in elective extrahepatic abdominopelvic surgery.

METHODS

PubMed, Embase, and ClinicalTrial.gov databases were searched to identify relevant RCTs from January 1947 to May 2020. The primary outcome, intraoperative blood loss, and secondary outcomes, need for perioperative blood transfusion, units of blood transfused, thromboembolic events, and mortality, were extracted from included studies. Quantitative pooling of data was based on a random-effects model.

RESULTS

Some 19 studies reporting on 2205 patients who underwent abdominal, pelvic, gynaecological or urological surgery were included. TXA reduced intraoperative blood loss (mean difference -188.35 (95 per cent c.i. -254.98 to -121.72) ml) and the need for perioperative blood transfusion (odds ratio (OR) 0.43, 95 per cent c.i. 0.28 to 0.65). TXA had no impact on the incidence of thromboembolic events (OR 0.49, 0.18 to 1.35). No adverse drug reactions or in-hospital deaths were reported.

CONCLUSION

TXA reduces intraoperative blood loss during elective extrahepatic abdominal and pelvic surgery without an increase in complications.

Protocol for a multicentre prehospital randomised controlled trial investigating tranexamic acid in severe trauma: the PATCH-Trauma trial

INTRODUCTION

Haemorrhage causes most preventable prehospital trauma deaths and about a third of in-hospital trauma deaths. Tranexamic acid (TXA), administered soon after hospital arrival in certain trauma systems, is an effective therapy in preventing or managing acute traumatic coagulopathy. However, delayed administration of TXA appears to be ineffective or harmful. The effectiveness of prehospital TXA, incidence of thrombotic complications, benefit versus risk in advanced trauma systems and the mechanism of benefit remain uncertain.

METHODS AND ANALYSIS

The Pre-hospital Anti-fibrinolytics for Traumatic Coagulopathy and Haemorrhage (The PATCH-Trauma study) is comparing TXA, initiated prehospital and continued in hospital over 8 hours, with placebo in patients with severe trauma at risk of acute traumatic coagulopathy. We present the trial protocol and an overview of the statistical analysis plan. There will be 1316 patients recruited by prehospital clinicians in Australia, New Zealand and Germany. The primary outcome will be the eight-level Glasgow Outcome Scale Extended (GOSE) at 6 months after injury, dichotomised to favourable (GOSE 5-8) and unfavourable (GOSE 1-4) outcomes, analysed using an intention-to-treat (ITT) approach. Secondary outcomes will include mortality at hospital discharge and at 6 months, blood product usage, quality of life and the incidence of predefined adverse events.

ETHICS AND DISSEMINATION

The study was approved by The Alfred Hospital Research and Ethics Committee in Victoria and also approved in New South Wales, Queensland, South Australia, Tasmania and the Northern Territory. In New Zealand, Northern A Health and Disability Ethics Committee provided approval. In Germany, Witten/Herdecke University has provided ethics approval. The PATCH-Trauma study aims to provide definitive evidence of the effectiveness of prehospital TXA, when used in conjunction with current advanced trauma care, in improving outcomes after severe injury.

TRIAL REGISTRATION NUMBER

NCT02187120.

Do all cardiac surgery patients benefit from antifibrinolytic therapy?

BACKGROUND

In trauma patients, the recognition of fibrinolysis phenotypes has led to a re-evaluation of the risks and benefits of antifibrinolytic therapy (AF). Many cardiac patients also receive AF, but the distribution of fibrinolytic phenotypes in that population is unknown. The purpose of this hypothesis-generating study was to fill that gap.

METHODS

Seventy-eight cardiac surgery patients were retrospectively reviewed. Phenotypes were defined as hypofibrinolytic (LY30 <0.8%), physiologic (0.8%-3.0%), and hyperfibrinolytic (>3%) based on thromboelastogram.

RESULTS

The population was 65 ± 10-years old, 74% male, average body mass index of 29 ± 5 kg/m² . Fibrinolytic phenotypes were distributed as physiologic = 45% (35 of 78), hypo = 32% (25 of 78), and hyper = 23% (18 of 78). There was no obvious effect of age, gender, race, or ethnicity on this distribution; 47% received AF. For AF versus no AF, the time with chest tube was longer (4 [1] vs. 3 [1] days, p = .037), and all-cause morbidity was more prevalent (51% vs. 25%, p = .017). However, when these two groups were further stratified by phenotypes, there were within-group differences in the percentage of patients with congestive heart failure (p = .022), valve disease (p = .024), on-pump surgery (p < .0001), estimated blood loss during surgery (p = .015), transfusion requirement (p = .015), and chest tube output (p = .008), which highlight other factors along with AF that might have affected all-cause morbidity.

CONCLUSION

This is the first description of the prevalence of three different fibrinolytic phenotypes and their potential influence on cardiac surgery patients. The use of AF was associated with increased morbidity, but because of the small sample size and treatment allocation bias, additional confirmatory studies are necessary. We hope these present findings open the dialog on whether it is safe to administer AFs to cardiac surgery patients who are normo- or hypofibrinolytic.

Efficacy of Tranexamic Acid in Reducing Blood Loss in Lower Segment Cesearean Section: A Randomised Controlled Study

Objectives

To determine the efficacy of tranexamic acid in decreasing blood loss in elective/emergency LSCS.

Materials and Methods

A prospective randomised case control study was done in 200 pregnant women undergoing elective/emergency LSCS in the Department of Obstetrics and Gynaecology, at a tertiary care teaching hospital in Mysuru, from December 2018 to September 2019. Women in the age group of 18-35 years were included in the study. Those with anaemia (Hb < 10 gm%), hypertension in pregnancy, bleeding diathesis, GDM on insulin, polyhydramnios, oligohydramnios, cardiac and chronic liver disorders were excluded from the study. Two hundred women undergoing emergency/elective LSCS were divided into case (group 1) or control (group 2) groups using a computer-generated random number table. Tranexamic acid (10 mg/Kg) was given in 100 ml Normal Saline 10 mins prior to skin incision to women in the first group, along with routine care (10 Units of Oxytocin IM soon after extraction of the baby). Routine care, as per institutional protocol, was followed in the second group. The primary outcome was to estimate the intraoperative blood loss. Blood loss was measured by weighing pads, mops, drapes before and after surgery and blood in the suction container after surgery. Two separate suction catheters and containers were used, in order to minimise mixing of blood and amniotic fluid. Total blood loss was calculated as the difference in the weight of the pads, mops and drapes before and after surgery and the sum of the amount of blood in suction container. The difference between the pre-operative and post-operative haemoglobin and haematocrit was compared. The pre-operative, intra-operative and post-operative hemodynamics were also compared.

Results

Statistical analysis was done using MS Excel and R-3.5.1 software. Unpaired and paired t test were used. In our study, there was a significant decrease in intraoperative bleeding in women receiving tranexamic acid. Women in the control group had a significant fall in the postoperative hemoglobin when compared to women who received tranexamic acid. Also, women who received tranexamic acid did not develop any significant hemodynamic changes during or immediately after the surgery.

Conclusion

Tranexamic acid can be safely used as a prophylactic agent to reduce bleeding during elective and emergency LSCS.

The many roles of tranexamic acid: An overview of the clinical indications for TXA in medical and surgical patients

Clinically significant bleeding can occur as a consequence of surgery, trauma, obstetric complications, anticoagulation, and a wide variety of disorders of hemostasis. As the causes of bleeding are diverse and not always immediately apparent, the availability of a safe, effective, and non-specific hemostatic agent is vital in a wide range of clinical settings, with antifibrinolytic agents often utilized for this purpose. Tranexamic acid (TXA) is one of the most commonly used and widely researched antifibrinolytic agents; its role in postpartum hemorrhage, menorrhagia, trauma-associated hemorrhage, and surgical bleeding has been well defined. However, the utility of TXA goes beyond these common indications, with accumulating data suggesting its ability to reduce bleeding and improve clinical outcomes in the face of many different hemostatic challenges, without a clear increase in thrombotic risk. Herein, we review the literature and provide practical suggestions for clinical use of TXA across a broad spectrum of bleeding disorders.

Massive transfusion in The Netherlands

OBJECTIVES

Massive transfusion protocols (MTPs) may improve survival in patients with uncontrolled haemorrhage. An MTP was introduced into the Dutch transfusion guidelines in 2011, the ninth edition of the advanced trauma life support course in 2012 and the third version of the European guideline in 2013. This is the first survey of MTPs in Dutch trauma centres.

METHODS

The aim of the study was to compare MTP strategies in level 1 trauma centres in The Netherlands, and with (inter)national guidelines. A contact in each government assigned level 1 trauma centre in The Netherlands and the Dutch Ministry of Defence was approached to share their MTPs and elucidate their protocol in a survey and oral follow-up interview.

RESULTS

All 11 level 1 trauma centres responded. The content of the packages and transfusion ratios (red blood cells/plasma/platelets) were 3:3:1, 5:5:1, 5:3:1, 2:3:1, 4:4:1, 5:2:1, 2:2:1 and 4:3:1. Tranexamic acid was used in all centres and an additional dose was administered in eight centres. Fibrinogen was given directly (n=4), with persistent bleeding (n=3), based on Clauss fibrinogen (n=3) or rotational thromboelastometry (n=1). All centres used additional medication in patients in the form of anticoagulants, but their use was ambiguous.

CONCLUSION

MTPs differed between institutes and guidelines. The discrepancies in transfusion ratios can be explained by (inter)national differences in preparation and volume of blood components and/or interpretation of the '1:1:1' guideline. We recommend updating MTPs every year using the latest guidelines and evaluating the level of evidence for treatment during massive transfusion.

Tranexamic Acid for Acute Hemorrhage: A Narrative Review of Landmark Studies and a Critical Reappraisal of Its Use Over the Last Decade

The publication of the Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage-2 (CRASH-2) study and its intense dissemination prompted a renaissance for the use of the antifibrinolytic agent tranexamic acid (TXA) in acute trauma hemorrhage. Subsequent studies led to its widespread use as a therapeutic as well as prophylactic agent across different clinical scenarios involving bleeding, such as trauma, postpartum, and orthopedic surgery. However, results from the existing studies are confounded by methodological and statistical ambiguities and are open to varied interpretations. Substantial knowledge gaps remain on dosing, pharmacokinetics, mechanism of action, and clinical applications for TXA. The risk for potential thromboembolic complications with the use of TXA must be balanced against its clinical benefits. The present article aims to provide a critical reappraisal of TXA use over the last decade and a "thought exercise" in the potential downsides of TXA. A more selective and individualized use of TXA, guided by extended and functional coagulation assays, is advocated in the context of the evolving concept of precision medicine.

Recent Advances in Hemostasis at the Nanoscale

Rapid and effective hemostatic materials have received wide attention not only in the battlefield but also in hospitals and clinics. Traditional hemostasis relies on materials with little designability which has many limitations. Nanohemostasis has been proposed since the use of peptides in hemostasis. Nanomaterials exhibit excellent adhesion, versatility, and designability compared to traditional materials, laying a good foundation for future hemostatic materials. This review first summarizes current hemostatic methods and materials, and then introduces several cutting-edge designs and applications of nanohemostatic materials such as polypeptide assembly, electrospinning of cyanoacrylate, and nanochitosan. Particularly, their advantages and working mechanisms are introduced. Finally, the challenges and prospects of nanohemostasis are discussed.

Geographical Variance in the Use of Tranexamic Acid for Major Trauma Patients

Background and Objectives: The CRASH-2 trial is the largest randomised control trial examining tranexamic acid (TXA) for injured patients. Since its publication, debate has arisen around whether results could be applied to mature trauma systems in developed nations, with global opinion divided. The aim of this study was to determine if, among trauma patients in or at significant risk of major haemorrhages, there is an association of geographic region with the proportion of patients that received tranexamic acid. Materials and Methods: We conducted a systematic review of the literature. Potentially eligible papers were first screened via title and abstract screening. A full copy of the remaining papers was then obtained and screened for final inclusion. The Newcastle-Ottawa Scale for non-randomised control trials was used for quality assessment of the final studies included. A meta-analysis was conducted using a random-effects model, reporting variation in use sub-grouped by geographical location. Results: There were 727 papers identified through database searching and 23 manuscripts met the criteria for final inclusion in this review. There was a statistically significant variation in the use of TXA for included patients. Europe and Oceania had higher usage rates of TXA compared to other continents. Use of TXA in Asia and Africa was significantly less than other continents and varied use was observed in North America. Conclusions: A large geographical variance in the use of TXA for trauma patients in or at significant risk of major haemorrhage currently exists. The populations in Asia and Africa, where the results of CRASH-2 could be most readily generalised to, reported low rates of use. The reason why remains unclear and further research is required to standardise the use of TXA for trauma resuscitation.

Early prediction of acute traumatic coagulopathy: a validation of the COAST score using the German Trauma Registry

BACKGROUND

Early identification of trauma patients at risk of developing acute traumatic coagulopathy (ATC) is important for initiating appropriate, coagulopathy-focused treatment. A clinical ATC prediction tool is a quick, simple method to evaluate risk. The COAST score was developed and validated in Australia but is yet to be validated on a European population. We validated the ability of the COAST score to predict coagulopathy and adverse bleeding-related outcomes on a large European trauma population.

METHODS

The COAST score was modified and applied to a retrospective cohort of trauma patients from the German Trauma Registry (TR-DGU). The primary outcome was coagulopathy defined as INR > 1.5 or aPTT > 60 s. Secondary outcomes were massive transfusion, blood product requirements, urgent surgery and mortality. The cohort included adult trauma patients with Injury Severity Score > 15 treated in Germany/Austria in 2012-2016.

RESULTS

15,370 cases were included, of which 10.9% were coagulopathic. The COAST score performed with sensitivity 21.6% and specificity 94.2% at a threshold of COAST ≥ 3. The AUROC was 0.625 (95% CI 0.61-0.64). The COAST score also identified patients who had more massive transfusions (15.3% v 1.6%), more emergency surgery (49.6% v 28.2%), and higher early (21.7% v 5.4%) and total in-hospital mortality (38.1% v 14.5%).

CONCLUSION

This large retrospective study demonstrated that the modified COAST score predicts coagulopathy with low sensitivity but high specificity. A positive COAST score identified a group of patients with bleeding-related adverse outcomes. This score appears adequate to act as an inclusion criterion for clinical trials targeting ATC.

Tranexamic acid is associated with selective increase in inflammatory markers following total knee arthroplasty (TKA): a pilot study

BACKGROUND

Tranexamic acid (TXA) is commonly used in orthopedic surgery to reduce excessive bleeding and transfusion requirements. Our aim was to examine if TXA was required in all osteoarthritis patients undergoing TKA surgery, and its possible effects on systemic inflammation and coagulation properties.

METHODS

Twenty-three patients (Oxford Score 22-29) were recruited consecutively; 12 patients received TXA before (IV, 1.2 g/90 kg) and immediately after surgery (intra-articular, 1.4 g/90 kg). Inflammatory mediators and ROTEM parameters were measured in blood at baseline, after the first bone-cut, immediately after surgery, and postoperative days 1 and 2.

RESULTS

After the bone cut and surgery, TXA significantly increased MCP-1, TNF-α, IL-1β and IL-6 levels compared to non-TXA patients, which was further amplified postoperatively. During surgery, TXA significantly prolonged EXTEM clot times, indicating a thrombin-slowing effect, despite little or no change in clot amplitude or fibrinogen. TXA was associated with three- to fivefold increases in FIBTEM maximum lysis (ML), a finding counter to TXA's antifibrinolytic effect. Maximum lysis for extrinsic and intrinsic pathways was < 8%, indicating little or no hyperfibrinolysis. No significant differences were found in postoperative hemoglobin between the two groups.

CONCLUSIONS

TXA was associated with increased systemic inflammation during surgery compared to non-TXA patients, with further amplification on postoperative days 1 and 2. On the basis of little or no change in viscoelastic clot strength, fibrinogen or clot lysis, there appeared to be no clinical justification for TXA in our group of patients. Larger prospective, randomized trials are required to investigate a possible proinflammatory effect in TKA patients.

Effect of Tranexamic Acid on Blood Loss, D-Dimer, and Fibrinogen Kinetics in Adult Spinal Deformity Surgery

BACKGROUND

Antifibrinolytics such as tranexamic acid reduce operative blood loss and blood product transfusion requirements in patients undergoing surgical correction of scoliosis. The factors involved in the unrelenting coagulopathy seen in scoliosis surgery are not well understood. One potential contributor is activation of the fibrinolytic system during a surgical procedure, likely related to clot dissolution and consumption of fibrinogen. The addition of tranexamic acid during a surgical procedure may mitigate the coagulopathy by impeding the derangement in D-dimer and fibrinogen kinetics.

METHODS

We retrospectively studied consecutive patients who had undergone surgical correction of adult spinal deformity between January 2010 and July 2016 at our institution. Intraoperative hemostatic data, surgical time, estimated blood loss, and transfusion records were analyzed for patients before and after the addition of tranexamic acid to our protocol. Each patient who received tranexamic acid and met inclusion criteria was cohort-matched with a patient who underwent a surgical procedure without tranexamic acid administration.

RESULTS

There were 17 patients in the tranexamic acid cohort, with a mean age of 60.7 years, and 17 patients in the control cohort, with a mean age of 60.9 years. Estimated blood loss (932 ± 539 mL compared with 1,800 ± 1,029 mL; p = 0.005) and packed red blood-cell transfusions (1.5 ± 1.6 units compared with 4.0 ± 2.1 units; p = 0.001) were significantly lower in the tranexamic acid cohort. In all single-stage surgical procedures that met inclusion criteria, the rise of D-dimer was attenuated from 8.3 ± 5.0 μg/mL in the control cohort to 3.3 ± 3.2 μg/mL for the tranexamic acid cohort (p < 0.001). The consumption of fibrinogen was 98.4 ± 42.6 mg/dL in the control cohort but was reduced in the tranexamic acid cohort to 60.6 ± 35.1 mg/dL (p = 0.004).

CONCLUSIONS

In patients undergoing spinal surgery, intravenous administration of tranexamic acid is effective at reducing intraoperative blood loss. Monitoring of D-dimer and fibrinogen during spinal surgery suggests that tranexamic acid impedes the fibrinolytic pathway by decreasing consumption of fibrinogen and clot dissolution as evidenced by the reduced formation of D-dimer.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Blood products and procoagulants in traumatic bleeding: use and evidence

PURPOSE OF REVIEW

Death from uncontrolled haemorrhage is one of the leading causes of trauma-related mortality and is potentially preventable. Advances in understanding the mechanisms of trauma-induced coagulopathy (TIC) have focused attention on the role of blood products and procoagulants in mitigating the sequelae of TIC and how these therapies can be improved.

RECENT FINDINGS

A host of preclinical and clinical studies have evaluated blood product availability and efficacy in trauma. Recently published randomized controlled trials have investigated the ratio of platelet:plasma:red cell transfusion and the role of early cryoprecipitate in trauma. Demand for readily available plasma has led to changes particularly in the use of thawed group A plasma. Furthermore, ex-vivo and early clinical work has demonstrated variations in the haemostatic activity of different plasma, platelet and whole blood products. A number of multicentre trials are in progress aiming to answer key questions regarding tranexamic acid, procoagulant factor and fibrinogen concentrates and their effect on trauma outcomes.

SUMMARY

There are promising results from ex-vivo studies in manufacturing and storage of blood products to optimize haemostatic activity and availability, particularly with alternative plasma and platelet products and whole blood. There is an urgent need for these products needs to be tested prospectively.

Antifibrinolytic Therapy and Perioperative Considerations

Fibrinolysis is a physiologic component of hemostasis that functions to limit clot formation. However, after trauma or surgery, excessive fibrinolysis may contribute to coagulopathy, bleeding, and inflammatory responses. Antifibrinolytic agents are increasingly used to reduce bleeding, allogeneic blood administration, and adverse clinical outcomes. Tranexamic acid is the agent most extensively studied and used in most countries. This review will explore the role of fibrinolysis as a pathologic mechanism, review the different pharmacologic agents used to inhibit fibrinolysis, and focus on the role of tranexamic acid as a therapeutic agent to reduce bleeding in patients after surgery and trauma.

Nano- and micro-materials in the treatment of internal bleeding and uncontrolled hemorrhage

Internal bleeding is defined as the loss of blood that occurs inside of a body cavity. After a traumatic injury, hemorrhage accounts for over 35% of pre-hospital deaths and 40% of deaths within the first 24 hours. Coagulopathy, a disorder in which the blood is not able to properly form clots, typically develops after traumatic injury and results in a higher rate of mortality. The current methods to treat internal bleeding and coagulopathy are inadequate due to the requirement of extensive medical equipment that is typically not available at the site of injury. To discover a potential route for future research, several current and novel treatment methods have been reviewed and analyzed. The aim of investigating different potential treatment options is to expand available knowledge, while also call attention to the importance of research in the field of treatment for internal bleeding and hemorrhage due to trauma.

Administration of tranexamic acid in trauma patients under stricter inclusion criteria increases the treatment window for stabilization from 24 to 48 hours-a retrospective review

BACKGROUND

Since 2010, the use of Tranexamic Acid (TXA) in trauma has been brought to the forefront of severe hemorrhage treatment. However, the mixed literature illustrates the need for additional proof of efficacy and determining which patients may benefit from TXA. The purpose of this retrospective study was to evaluate a more stringent TXA inclusion criterion (heart rate ≥ 120 beats per minute (BPM) with a systolic blood pressure (SBP) ≤ 90 mmHg) as compared to the standard CRASH-2 inclusion criteria.

METHODS

From 2013-2016 a total of 115 patients (control, n = 62; TXA, n = 53) were included in the analysis. These patients adhered to the standard CRASH-2 and more stringent inclusion criteria; they also survived at least 8.5 hrs (minimum amount of time required for full TXA dose) from the initiation. Basic characteristics of the patients were summarized. The mortality rates between TXA and control groups were compared using two proportion z-tests. All p values <0.05 were considered statistically significant.

RESULTS

There was no statistical significant difference in patient characteristics between the two treatment groups, making them more comparable (p value >0.05). This study found a significant reduction of percent mortality at the 24 hr time point against the control (p = 0.007). Additionally, utilizing the more strict inclusion criteria (BPM ≥ 120 and SBP ≤ 90) substantially extended time to stabilize patients to 48 hrs (p = 0.029).

CONCLUSION

By imposing the more strict criteria, TXA appears to be a better treatment option in reducing mortality rates and potentially extends the treatment time-frame for stabilizing the patient up to 48 hours.

Compliance of tranexamic acid administration to trauma patients at a level-one trauma centre

Introduction Current practice for the treatment of traumatic hemorrhage includes fluid resuscitation and the administration of blood products. The administration of tranexamic acid (TXA) within 8 hours of injury has been shown to significantly reduce mortality in a large, prospective, randomized controlled trial. As a result, TXA is widely used in trauma centres to manage trauma patients with major bleeding. The primary aim of this study was to assess the compliance of TXA administration at a level-one trauma centre in Hamilton, Ontario, Canada.

METHODS

We conducted a retrospective medical record review of consecutive adult trauma patients received at the Hamilton General Hospital between January 1, 2012 and December 31, 2014. Compliance with TXA administration was based on the inclusion criteria of the CRASH-2 trial.

RESULTS

Five hundred and thirty-four of 2,475 trauma patients met the inclusion criteria for TXA administration. Twenty-one patients who received TXA at peripheral hospital prior to their arrival at the level-one trauma centre were excluded from the analysis, and 18 patients were excluded due to missing data. One hundred and thirty-four patients received TXA, representing a compliance rate of 27%. Mean time from arrival to TXA administration was 47 minutes. Compliance increased for those who required massive transfusion and as the number of criteria for TXA administration increased.

CONCLUSIONS

Compliance with TXA administration to trauma patients with suspected major bleeding was low. Quality improvement strategies aimed at increasing appropriate use of TXA are warranted.

Tissue injury suppresses fibrinolysis after hemorrhagic shock in nonhuman primates (rhesus macaque)

BACKGROUND

Hypoperfusion is associated with hyperfibrinolysis and early death from exsanguination, whereas tissue trauma is associated with hypofibrinolysis and delayed death from organ failure. We sought to elucidate the effects of injury patterns on fibrinolysis phenotypes using a nonhuman primate (NHP) model.

METHODS

NHPs were randomized to three injury groups (n = 8/group): 60 minutes severe pressure-targeted controlled hemorrhagic shock (HS); HS + soft tissue injury (HS+); or HS + soft tissue injury + femur fracture (HS++). Animals were resuscitated and monitored for 360 minutes. Blood samples were collected at baseline, end-of-shock, end-of-resuscitation (EOR), and T = 360 minutes for assessments of: severity of shock (lactate) and coagulation via prothrombin time, partial thromboplastin time, D-dimer, fibrinogen, antithrombin-III, von Willebrand factor, and viscoelastic testing (ROTEM). Results are reported as mean ± SEM; statistics: two-way analysis of variance and t-tests (significance: p < 0.05).

RESULTS

Blood loss, prothrombin time, partial thromboplastin time, antithrombin-III, fibrinogen, and von Willebrand factor were equivalent among groups and viscoelastic testing revealed few differences throughout the study. D-dimer increased approximately threefold, at EOR in the HS group, and at T = 360 minutes in the HS+ and HS++ groups (p < 0.05). At EOR, in the HS group compared with the HS+ and HS++ groups; the D-dimer-lactate ratio was twofold greater (2.2 ± 0.3 vs. 1.1 ± 0.3 and 1.1 ± 0.2, respectively; p < 0.05) and tissue factor-activated fibrin clot 30-minute lysis index was lower (98 ± 1% vs. 100 ± 0% and 100 ± 0%, respectively; p < 0.05).

CONCLUSION

NHPs in HS exhibit acute suppression of fibrinolysis in the presence of tissue injury. Additional assessments to more comprehensively evaluate the mechanisms linking tissue injury with the observed fibrinolysis shutdown response are warranted.

Rationale for the selective administration of tranexamic acid to inhibit fibrinolysis in the severely injured patient

Postinjury fibrinolysis can manifest as three distinguishable phenotypes: 1) hyperfibrinolysis, 2) physiologic, and 3) hypofibrinolysis (shutdown). Hyperfibrinolysis is associated with uncontrolled bleeding due to clot dissolution; whereas, fibrinolysis shutdown is associated with organ dysfunction due to microvascular occlusion. The incidence of fibrinolysis phenotypes at hospital arrival in severely injured patients is: 1) hyperfibrinolysis 18%, physiologic 18%, and shutdown 64%. The mechanisms responsible for dysregulated fibrinolysis following injury remain uncertain. Animal work suggests hypoperfusion promotes fibrinolysis, while tissue injury inhibits fibrinolysis. Clinical experience is consistent with these observations. The predominant mediator of postinjury hyperfibrinolysis appears to be tissue plasminogen activator (tPA) released from ischemic endothelium. The effects of tPA are accentuated by impaired hepatic clearance. Fibrinolysis shutdown, on the other hand, may occur from inhibition of circulating tPA, enhanced clot strength impairing the binding of tPA and plasminogen to fibrin, or the inhibition of plasmin. Plasminogen activator inhibitor -1 (PAI-1) binding of circulating tPA appears to be a major mechanism for postinjury shutdown. The sources of PAI-1 include endothelium, platelets, and organ parenchyma. The laboratory identification of fibrinolysis phenotype, at this moment, is best determined with viscoelastic hemostatic assays (TEG, ROTEM). While D-dimer and plasmin antiplasmin (PAP) levels corroborate fibrinolysis, they do not provide real-time assessment of the circulating blood capacity. Our clinical studies indicate that fibrinolysis is a very dynamic process and our experimental work suggests plasma first resuscitation reverses hyperfibrinolysis. Collectively, we believe recent clinical and experimental work suggest antifibrinolytic therapy should be employed selectively in the acutely injured patient, and optimally guided by TEG or ROTEM.

Tranexamic acid leads to paradoxical coagulation changes during cardiac surgery: a pilot rotational thromboelastometry study

BACKGROUND

Tranexamic acid (TXA) is increasingly used during major surgery with the goal to reduce excessive bleeding, transfusion requirements, and reexploration. Our aim was to examine the effect of TXA on coagulation at different times during cardiac surgery using rotational thromboelastometry.

MATERIALS AND METHODS

Nineteen adult males (EuroSCORE 4-5) were recruited consecutively for first-time cardiopulmonary bypass (CPB) surgery. Ten patients received TXA at anesthesia and nine received no TXA. Rotational thromboelastometry analysis occurred before anesthesia (baseline), after sternotomy, after CPB-heparinization and surgery, and after protamine administration-sternal closure.

RESULTS

A median sternotomy had no effect on clot time (CT), formation, amplitude, or lysis in non-TXA patients. In contrast, TXA patients had twofold prolonged clotting time (all-tests) and ∼30% reduced FIBTEM (A5-30) and maximum clot firmness, indicating reduced thrombin generation and lower clot fibrinogen. After CPB, CTs in both groups were prolonged, possibly linked to overheparinization. In addition, TXA patients had significantly decreased EXTEM (A5-30), suggesting lower clot strength. After protamine-sternal closure, clotting time remained prolonged in both groups, and TXA patients had a persistently 25%-33% lower FIBTEM (A5-30) and maximum clot firmness. TXA patients also had significantly reduced platelet numbers (37% from baseline), which continued Days 1 and 2. Maximum clot lysis was <10% indicating little or no hyperfibrinolysis during cardiac surgery.

CONCLUSIONS

In this nonrandomized, nonblinded, observational trial, patients in the TXA group displayed prolonged CTs and clot fibrinogen (FIBTEM A5-30) after sternotomy, decreased clot strength (EXTEM) after CPB/surgery, and acute thrombocytopenia after protamine-sternal closure. There was no significant decrease in clot lysis, questioning the need for TXA in this medium-risk group.

Tranexamic Acid (TXA) in Trauma Patients: Barriers to Use among Trauma Surgeons and Emergency Physicians

Objective. Tranexamic Acid (TXA) is currently the only drug with prospective clinical evidence supporting its use in bleeding trauma patients. We sought to better understand the barriers preventing its use and elicit suggestions to further its use in trauma patients in the state of Maryland. Methods. This is a cross-sectional study. Results. The overall response rate was 38%. Half of all participants reported being familiar with the CRASH-2 trial and MATTERs study. Half reported being aware of TXA as part of their institution's massive transfusion protocol. The majority of participants felt that TXA would have a significant positive impact on the survival of trauma patients. A majority also felt that the use of TXA would increase if its administration was the responsibility of both trauma surgeons and emergency physicians. Conclusion. Only half of responders reported being aware of TXA as being part of their institution's massive transfusion protocol. Lack of awareness of the clinical data supporting its use is a major barrier. However, most trauma providers and emergency physicians do have a favorable view of TXA and support its incorporation into massive transfusion protocols. We believe that more studies of this kind on both state and national level are needed.