Tranexamic acid in control of haemorrhage after dental extraction in haemophilia and Christmas disease

Stress-Induced Hypercoagulability: Insights from Epidemiological and Mechanistic Studies, and Clinical Integration

By integrating findings from comprehensive reviews, meta-analyses, and cutting-edge genetic studies, this article illuminates the significance of stress-induced hypercoagulability in clinical medicine. In particular, the findings from numerous prospective cohort studies indicate that stress and hemostatic factors of a hypercoagulable state are associated with increased incident risk and poor prognosis for atherosclerotic cardiovascular disease and venous thromboembolism. Mendelian randomization studies suggest that these associations are partially causal. The review synthesizes extensive research on the link between acute and chronic stress and hypercoagulability, outlining a potential pathway from stress to thrombosis risk. Consistent with the allostatic load concept, acute stress-induced hypercoagulability, initially adaptive, can turn maladaptive under chronic stress or excessive acute stress, leading to arterial or venous thrombotic events. Individuals with predisposing factors, including atherosclerosis, thrombophilia, or immobilization, may exhibit an increased risk of thrombotic disease during stress. Contextual sociodemographic characteristics, the stress experience, and coping resources additionally modulate the extent of stress-induced hypercoagulability. Research into the neuroendocrine, cellular, and molecular bases reveals how stress influences platelet activation coagulation and fibrinolysis. The activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis, along with vagal withdrawal, and the effects of catecholamines, cortisol, and vasopressin, are the central mechanisms involved. Hemoconcentration, inflammation, endothelial dysfunction, and thrombopoiesis additionally contribute to stress-induced hypercoagulability. Further research is needed to prove a causal link between chronic stress and hypercoagulability. This includes exploring its implications for the prevention and management of thrombotic diseases in stressed individuals, with a focus on developing effective psychosocial and pharmacological interventions.

Use of crushed tranexamic acid tablets in water for paediatric patients with bleeding disorders

BACKGROUND

Ε-Aminocaproic acid oral solution (EACA OS) is the only commercially available antifibrinolytic for patients who cannot swallow tablets. Insurance denials and high costs remain barriers to its use.

OBJECTIVES

To determine the safety and efficacy of crushed tranexamic acid tablets in water (cTXAw) for children with bleeding disorders.

METHODS

We retrospectively reviewed records of children (<10 years) with bleeding disorders who received cTXAw or EACA OS from 1 December 2018, through 31 July 2022, at Mayo Clinic (Rochester, Minnesota). Bleeding outcomes were defined according to ISTH criteria.

RESULTS

Thirty-two patients were included (median age, 3 years; male, n = 23). Diagnoses were VWD (n = 17), haemophilia (n = 5), FVII deficiency (n = 3), inherited platelet disorder (n = 4), ITP (n = 2), and combined FV and FVII deficiencies (n = 1). Thirty-two courses of cTXAw (monotherapy 24/32; mean duration 6 days) and fifteen courses of EACA (monotherapy 12/15; mean duration 5 days) were administered. No surgical procedures (n = 28) were complicated by bleeding. Of the 19 bleeding events, 16 had effective haemostasis, two had no reported outcome, and one had no response. cTXAw and EACA were equally effective in preventing and treating bleeding (p value > .1). No patients had adverse effects. Eight of 19 patients (42%) who were initially prescribed EACA OS did not receive it because of cost or insurance denial. The estimated average wholesale price of one treatment was $94 for cTXAw and $905 for EACA OS.

CONCLUSIONS

CTXAw appears to be an effective, safe, and low-cost alternative option to EACA OS for young children with bleeding disorders.

Safety and Outcomes in Multiplane Facial Rejuvenation with Tranexamic Acid: A Cohort Study

Background

Tranexamic acid (TXA) has demonstrated promising outcomes in plastic surgery. Our aim was to assess the effect of TXA in intraoperative bleeding, operative time, and complications among patients undergoing facial surgical procedures.

Methods

A retrospective cohort study of patients who underwent multiplane facial rhytidectomy from January 2018 to September 2022 at the Clinica Ziegler, Lima, Peru. Patients were divided into two groups according to the use of intravenous plus local infiltration of TXA. We performed the chi square test to assess associations among categorical variables, the Student t test and Mann-Whitney U test for categorical with continuous variables, and Pearson correlation for quantitative variables.

Results

A total of 100 patients were included with 50 patients in each group. The median age was 59.5 years and the majority were women (88%). The median operative time was 288.5 minutes. The TXA group presented less intraoperative bleeding (40 versus 90 mL, P < 0.05) and shorter operative time (237 versus 353 minutes, P < 0.05); no differences in the development of hematoma (2% versus 12%, P = 0.11), less ecchymosis (2% versus 36%, P < 0.05), edema (2% versus 100%, P < 0.05), and time to drain removal (3 versus 6 days, P < 0.05).

Conclusions

TXA improves the short- and long-term outcomes of patients who undergo multiplane facial rhytidectomy. It also decreases intraoperative bleeding by more than half and reduces the operative time by one third. Moreover, patients receiving TXA presented significantly less ecchymosis, edema, and time to drain removal.

Intravenous Tranexamic Acid Reduces Post-Operative Bleeding and Blood Transfusion in Patients Undergoing Aortic Surgery: A PRISMA-Compliant Systematic Review and Meta-Analysis

Background

Tranexamic acid (TXA), an antifibrinolytic agent, has been demonstrated to reduce blood loss and transfusion requirements in both cardiac and non-cardiac surgery. However, the evidence regarding the efficacy of intravenous TXA in aortic surgery has been seldomly analyzed. Therefore, the current study was performed to address this question.

Methods

Searches of PubMed, EMBASE, OVID, Cochrane Library and CNKI were conducted comprehensively for randomized controlled trials (RCTs) comparing intravenous TXA versus no-TXA. Independently and in duplicate, we reviewed titles, abstracts and full-text articles, extracted data and evaluated bias risks. A random effect or fixed effect model was utilized to pool data.

Results

The database search yielded 4 RCTs involving 273 patients. Meta-analysis revealed that, there was a significant reduction in bleeding volume within the first 4 hours post-operatively [(weighted mean difference (WMD) = -74.33; 95% confidence interval (CI): -133.55 to -15.11; p = 0.01)], and the first 24 hours post-operatively [(WMD = -228.91; 95% CI: -352.60 to -105.23; p = 0.0003)], post-operative red blood cell (RBC) transfusion volume [(WMD = -420.00; 95% CI: -523.86 to -316.14; p < 0.00001)], fresh frozen plasma (FFP) transfusion volume [(WMD = -360.35; 95% CI: -394.80 to -325.89; p < 0.00001)] and platelet concentrate (PC) transfusion volume [(WMD = -1.27; 95% CI: -1.47 to -1.07; p < 0.0001)] following intravenous TXA administration. In addition, intravenous TXA administration significantly decreased the incidence of postoperative complications (53/451 (8.2%) vs. 75/421 (13.9%); odds ratio (OR) = 0.47; 95% CI: 0.30 to 0.75; p = 0.001), according to this present meta-analysis.

Conclusions

The current study preliminarily demonstrated that, TXA significantly reduced postoperative bleeding, blood transfusion requirements and postoperative complications among patients undergoing aortic surgery. More well-designed studies are warrant to confirm the efficacy and safety of intravenous TXA in patients undergoing aortic surgery.

1,2,3-Triazole Derivatives as Novel Antifibrinolytic Drugs

Fibrinolysis is a natural process that ensures blood fluidity through the removal of fibrin deposits. However, excessive fibrinolytic activity can lead to complications in different circumstances, such as general surgery or severe trauma. The current antifibrinolytic drugs in the market, aminocaproic acid (EACA) and tranexamic acid (TXA), require high doses repetitively to maintain their therapeutic effect. These high doses are related to a number of side effects such as headaches, nasal symptoms, or gastrointestinal discomfort and severely limit their use in patients with renal impairment. Therefore, the discovery of novel antifibrinolytics with a higher specificity and lower dosage could vastly improve the applicability of these drugs. Herein, we synthesized a total of ten compounds consisting of a combination of three key moieties: an oxadiazolone, a triazole, and a terminal amine. The IC₅₀ of each compound was calculated in our clot lysis assays, and the best candidate (1) provided approximately a 2.5-fold improvement over the current gold standard, TXA. Molecular docking and molecular dynamics were used to perform a structure-activity relationship (SAR) analysis with the lysine binding site in the Kringle 1 domain of plasminogen. This analysis revealed that 1,2,3-triazole was crucial for the activity, enhancing the binding affinity through pi-pi stacking and polar interactions with Tyr72. The results presented in this work open the door to further investigate this new family as potential antifibrinolytic drugs.

Low dose prophylaxis and antifibrinolytics: Options to consider with proven benefits for persons with haemophilia

INTRODUCTION

Prophylaxis has become standard of care for persons with severe phenotype haemophilia (PWsH). However, 'standard prophylaxis' with either factor or non-factor therapies (emicizumab) is prohibitively expensive for much of the world. We sought to evaluate whether haemophilia care can be provided at a lower cost yet achieve good results using Lower dose/Lower frequency prophylaxis (LDP) and with increasing use of antifibrinolytics (Tranexamic acid and Epsilon amino caproic acid).

METHODS

We identified 12 studies that collectively included 335 PWsH using LDP. Additionally, we undertook a literature search regarding the benefits of antifibrinolytics in haemophilia care.

RESULTS

Identified studies show that LDP is far superior to no prophylaxis (On demand [OD] therapy) resulting in significant patient benefits. Patients on LDP showed (in comparison to patients OD) on average: 72% less total bleeds; 75% less joint bleeds; 91% less days lost from school; 77% less hospital admission days; and improved quality of life measures. These benefits come at similar or only slightly higher (< 2-fold greater) costs than OD therapy. Antifibrinolytics are effective adjunctive agents in managing bleeds (oral, nasal, intracranial, possibly other) and providing haemostasis for surgeries (particularly oral surgeries). Antifibrinolytics can substitute for more expensive factor concentrates or can reduce the use of such concentrates. There is evidence to show that antifibrinolytics may be used in conjunction with factor concentrates/emicizumab for more effective/less costly prophylaxis.

CONCLUSIONS

The use of LDP along with appropriate and increased use of antifibrinolytics offers less resourced countries good options for managing patients with haemophilia.

An Update on the Dental Management of Children with Haemophilia

Children with haemophilia present a bleeding risk and a challenge for dentists. Guidelines on the dental management of haemophilia patients are largely based on expert consensus. Many existing guidelines also provide generic guidance mainly for adult patients, which have been adapted for children. However, children have unique needs that require additional considerations. With limited evidence available, it is important that dentists have an understanding of the principles of both medical and dental management and have a close collaboration with the haematologist at all times. Therefore, this paper provides some key principles related to various aspects of dental management of children with haemophilia. Furthermore, there has been a recent update to the World Federation of Haemophilia (WFH) Guidelines for the Management of Haemophilia,¹ with references to novel medical therapies for haemophilia. Hence, this paper also aims to inform dentists with the standard and newer medical therapies for haemophilia, including a specific focus on the novel agent Emicizumab and the associated dental considerations.

Surgical management of patients with von Willebrand disease: summary of 2 systematic reviews of the literature

von Willebrand disease (VWD) is the most common inherited bleeding disorder. The management of patients with VWD who are undergoing surgeries is crucial to prevent bleeding complications. We systematically summarized the evidence on the management of patients with VWD who are undergoing major and minor surgeries to support the development of practice guidelines. We searched Medline and EMBASE from inception through October 2019 for randomized clinical trials (RCTs), comparative observational studies, and case series that compared maintaining factor VIII (FVIII) levels or von Willebrand factor (VWF) levels at >0.50 IU/mL for at least 3 days in patients undergoing major surgery, and those with options for perioperative management of patients undergoing minor surgery. Two authors screened and abstracted data and assessed the risk of bias. We conducted meta-analyses when possible. We evaluated the certainty of the evidence using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. We included 7 case series for major surgeries and 2 RCTs and 12 case series for minor surgeries. Very-low-certainty evidence showed that maintaining FVIII levels or VWF levels of >0.50 IU/mL for at least 3 consecutive days showed excellent hemostatic efficacy (as labeled by the researchers) after 74% to 100% of major surgeries. Low- to very-low-certainty evidence showed that prescribing tranexamic acid and increasing VWF levels to 0.50 IU/mL resulted in fewer bleeding complications after minor procedures compared with increasing VWF levels to 0.50 IU/mL alone. Given the low-quality evidence for guiding management decisions, a shared-decision model leading to individualized therapy plans will be important in patients with VWD who are undergoing surgical and invasive procedures.

Is Antifibrinolytic Therapy Effective for Preventing Hemorrhage in Patients with Hemophilia Undergoing Dental Extractions? A Systematic Review and Meta-Analysis

Objectives

This systematic review aims to analyze the systemic administration of antifibrinolytics (tranexamic acid and aminocaproic acid) to prevent postoperative bleeding in patients with hemophilia.

Methods

This systematic review was conducted adhering to PRISMA guidelines. Only randomized controlled trials that assessed human subjects of any age or gender with any severity of hemophilia undergoing dental extractions, and systemically administered antifibrinolytic therapy compared to placebo were included. Post-operative bleeding episodes and adverse events were presented. PubMed, Cochrane, Embase, CINAHL, Web of Science, and Scopus were searched through April 15, 2022. The risk ratio (RR) and odds ratio (OR) applying 95% confidence intervals (CI) were computed using RevMan 5.4.1 (Cochrane).

Results

Two randomized, placebo-controlled trials pooling in a total of 59 patients were pooled in this analysis. Among patients administered antifibrinolytic therapy, 84% reduced risk of post-operative bleeding was reported (RR = 0.16, 95% CI = 0.05–0.47, P = 0.0009). The chances of post-operative bleeding were reduced by 95% among the antifibrotics group (OR = 0.05, 95% CI = 0.01–0.22, P < 0.0001).

Conclusion

This review finds favorable outcomes for the routine use of antifibrinolytic therapy for dental extractions in hemophiliacs. Further trials are required to rationalize existing evidence.

Dentoalveolar Procedures in Immune Thrombocytopenia; Systematic Review and an Institutional Guideline

Background  Dentoalveolar procedures in immune thrombocytopenia (ITP) pose a risk of bleeding due to thrombocytopenia and infection due to immunosuppressive treatments. We aimed to systematically review the safety and management of dentoalveolar procedures in ITP patients to create practical recommendations.

Methods  PubMed, Embase, Cochrane, and Cinahl were searched for original studies on dentoalveolar procedures in primary ITP patients. We recorded bleeding- and infection-related outcomes and therapeutic strategies. Clinically relevant bleeding was defined as needing medical attention.

Results  Seventeen articles were included, of which 12 case reports/series. Overall, the quality of the available evidence was poor. Outcomes and administered therapies (including hemostatic therapies and prophylactic antibiotics) were not systematically reported. At least 73 dentoalveolar procedures in 49 ITP patients were described. The range of the preoperative platelet count was 2 to 412 × 10 ⁹ /L. Two clinically relevant bleedings (2%) were reported in the same patient of which one was life-threatening. Strategies used to minimize the risk of bleeding were heterogeneous and included therapies to increase platelet count, antifibrinolytics, local measures, and minimally invasive techniques. Reports on the occurrence of bleedings due to anesthetics or infection were lacking.

Conclusion  Based on alarmingly limited data, clinically relevant bleedings and infections after dentoalveolar procedures in ITP patients seem rare. Awaiting prospective and controlled studies to further evaluate these risks and the efficacy of therapeutic interventions, we provided our institutional guideline to guide the management of dentoalveolar procedures in ITP patients.

A reactive center loop-based prediction platform to enhance the design of therapeutic SERPINs

Serine proteases are essential for many physiological processes and require tight regulation by serine protease inhibitors (SERPINs). A disturbed SERPIN-protease balance may result in disease. The reactive center loop (RCL) contains an enzymatic cleavage site between the P1 through P1' residues that controls SERPIN specificity. This RCL can be modified to improve SERPIN function; however, a lack of insight into sequence-function relationships limits SERPIN development. This is complicated by more than 25 billion mutants needed to screen the entire P4 to P4' region. Here, we developed a platform to predict the effects of RCL mutagenesis by using α1-antitrypsin as a model SERPIN. We generated variants for each of the residues in P4 to P4' region, mutating them into each of the 20 naturally occurring amino acids. Subsequently, we profiled the reactivity of the resulting 160 variants against seven proteases involved in coagulation. These profiles formed the basis of an in silico prediction platform for SERPIN inhibitory behavior with combined P4 to P4' RCL mutations, which were validated experimentally. This prediction platform accurately predicted SERPIN behavior against five out of the seven screened proteases, one of which was activated protein C (APC). Using these findings, a next-generation APC-inhibiting α1-antitrypsin variant was designed (KMPR/RIRA; / indicates the cleavage site). This variant attenuates blood loss in an in vivo hemophilia A model at a lower dosage than the previously developed variant AIKR/KIPP because of improved potency and specificity. We propose that this SERPIN-based RCL mutagenesis approach improves our understanding of SERPIN behavior and will facilitate the design of therapeutic SERPINs.

Tranexamic acid for the prevention and treatment of bleeding in surgery, trauma and bleeding disorders: a narrative review

OBJECTIVES

We review the evidence for tranexamic acid (TXA) for the treatment and prevention of bleeding caused by surgery, trauma and bleeding disorders. We highlight therapeutic areas where evidence is lacking and discuss safety issues, particularly the concern regarding thrombotic complications.

METHODS

An electronic search was performed in PubMed and the Cochrane Library to identify clinical trials, safety reports and review articles.

FINDINGS

TXA reduces bleeding in patients with menorrhagia, and in patients undergoing caesarian section, myomectomy, hysterectomy, orthopedic surgery, cardiac surgery, orthognathic surgery, rhinoplasty, and prostate surgery. For dental extractions in patients with bleeding disorders or taking antithrombotic drugs, as well as in cases of idiopathic epistaxis, tonsillectomy, liver transplantation and resection, nephrolithotomy, skin cancer surgery, burn wounds and skin grafting, there is moderate evidence that TXA is effective for reducing bleeding. TXA was not effective in reducing bleeding in traumatic brain injury and upper and lower gastrointestinal bleeding. TXA reduces mortality in patients suffering from trauma and postpartum hemorrhage. For many of these indications, there is no consensus about the optimal TXA dose. With certain dosages and with certain indications TXA can cause harm, such as an increased risk of seizures after high TXA doses with brain injury and cardiac surgery, and an increased mortality after delayed administration of TXA for trauma events or postpartum hemorrhage. Whereas most trials did not signal an increased risk for thrombotic events, some trials reported an increased rate of thrombotic complications with the use of TXA for gastro-intestinal bleeding and trauma.

CONCLUSIONS

TXA has well-documented beneficial effects in many clinical indications. Identifying these indications and the optimal dose and timing to minimize risk of seizures or thromboembolic events is work in progress.

Comparison of the effect of tranexamic acid at various concentrations on the degradation time of platelet-rich fibrin

This study aimed to compare platelet-rich fibrin (PRF) membranes obtained using a conventional method and those obtained using the tranexamic acid-mixed method at various concentrations in terms of appearance, weight, and degradation period. In this in vitro study, 20 PRF membranes were divided into four groups, including a conventional group manipulated using the conventional method. The remaining groups were prepared using tranexamic acid at concentrations of 50, 150, and 200 mg. The PRF membranes were evaluated for gross weight, degradation period, and daily remaining weight for 28 days. There were no statistically significant differences in gross weight among all the groups (p = 0.985). The 150 and 200 mg groups had a longer degradation period (more than 28 days), which was significantly longer than that of the control and 50 mg groups (p = 0.048). The daily remaining weights of the 150 and 200 mg groups were significantly greater than that of the control group observed from day 13 to the end of the experiment. The tranexamic acid-mixed technique had no effect on the appearance and weight of the PRF membranes. Moreover, the technique could delay their degradation.

Assessing Plasmin Generation in Health and Disease

Fibrinolysis is an important process in hemostasis responsible for dissolving the clot during wound healing. Plasmin is a central enzyme in this process via its capacity to cleave fibrin. The kinetics of plasmin generation (PG) and inhibition during fibrinolysis have been poorly understood until the recent development of assays to quantify these metrics. The assessment of plasmin kinetics allows for the identification of fibrinolytic dysfunction and better understanding of the relationships between abnormal fibrin dissolution and disease pathogenesis. Additionally, direct measurement of the inhibition of PG by antifibrinolytic medications, such as tranexamic acid, can be a useful tool to assess the risks and effectiveness of antifibrinolytic therapy in hemorrhagic diseases. This review provides an overview of available PG assays to directly measure the kinetics of plasmin formation and inhibition in human and mouse plasmas and focuses on their applications in defining the role of plasmin in diseases, including angioedema, hemophilia, rare bleeding disorders, COVID-19, or diet-induced obesity. Moreover, this review introduces the PG assay as a promising clinical and research method to monitor antifibrinolytic medications and screen for genetic or acquired fibrinolytic disorders.

Is There a Role for Tranexamic Acid in Upper GI Bleeding? A Systematic Review and Meta-Analysis

Introduction

Upper gastrointestinal (GI) bleeding is associated with increased morbidity and mortality. Tranexamic acid (TXA) is an antifibrinolytic agent which is licensed in the management of haemorrhage associated with trauma. It has been suggested that tranexamic acid may be able to play a role in upper GI bleeding. However, there is currently no recommendation to support this.

Aim

The aim of this study was to synthesise available evidence of the effect of TXA on upper GI bleeding.

Methods and Materials

A systematic review was conducted. PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for relevant studies. A random effects meta-analysis was performed to determine the risk ratio of primary and secondary outcomes pertaining to the use of TXA in upper GI bleeding.

Results

A total of 8 studies were included in this systematic review. The total number of patients in all studies was 12994 including 4550 females (35%) and 8444 males (65%). The mean age of participants in 6 of the studies was 59.3; however the mean age for either intervention or placebo group was not reported in two of the studies. All studies reported on the effect of TXA on mortality, and the risk ratio was 0.95; however, with the 95% CI ranging from 0.80 to 1.13, this was not statistically significant. 6 of the studies reported on rebleeding rate, the risk ratio was 0.64, and with a 95% CI ranging from 0.47 to 0.86, this was statistically significant. 3 of the studies reported on the risk of adverse thromboembolic events, and the risk ratio was 0.93; however, the 95% CI extended from 0.62 to 1.39 and so was not statistically significant. 7 of the studies reported on the need for surgery, and the risk ratio was 0.59 and was statistically significant with a 95% CI ranging from 0.38 to 0.94.

Conclusion

In conclusion, the use of TXA in upper GI bleeding appears to have a beneficial effect in terms of decreasing the risk of re-bleeding and decreasing the need for surgery. However, we could not find a statistically significant effect on need for blood transfusions, risk of thromboembolic events, or effect on mortality. Future randomised controlled trials may elucidate these outcomes.

ASH ISTH NHF WFH 2021 guidelines on the management of von Willebrand disease

BACKGROUND

von Willebrand disease (VWD) is a common inherited bleeding disorder. Significant variability exists in management options offered to patients.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH), the International Society on Thrombosis and Haemostasis (ISTH), the National Hemophilia Foundation (NHF), and the World Federation of Hemophilia (WFH) are intended to support patients, clinicians, and health care professionals in their decisions about management of VWD.

METHODS

ASH, ISTH, NHF, and WFH formed a multidisciplinary guideline panel. Three patient representatives were included. The panel was balanced to minimize potential bias from conflicts of interest. The University of Kansas Outcomes and Implementation Research Unit and the McMaster Grading of Recommendations Assessment, Development and Evaluation (GRADE) Centre supported the guideline development process, including performing and updating systematic evidence reviews (through November 2019). The panel prioritized clinical questions and outcomes according to their importance to clinicians and patients. The panel used the GRADE approach, including GRADE Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 12 recommendations and outlined future research priorities.

CONCLUSIONS

These guidelines make key recommendations regarding prophylaxis for frequent recurrent bleeding, desmopressin trials to determine therapy, use of antiplatelet agents and anticoagulant therapy, target VWF and factor VIII activity levels for major surgery, strategies to reduce bleeding during minor surgery or invasive procedures, management options for heavy menstrual bleeding, management of VWD in the context of neuraxial anesthesia during labor and delivery, and management in the postpartum setting.

History of the West of Scotland Haemophilia Centre, Glasgow, 1950-2019

Over 70 years, the West of Scotland Haemophilia Centre in the UK has played a leading role in research, education and training. Its staff studied the natural history of haemophilias, their complications, and their treatment complications, pioneered the use of fibrinolytic inhibitors to reduce the risk of receiving a blood transfusion and developed national audit. Collaborations across Scotland with other haemophilia centres and the Scottish National Blood Transfusion Service progressed self-suffi ciency in NHS-produced factor concentrates, heat treatments to prevent HIV and hepatitis transmission, and finally, replacement of human by recombinant factor concentrates.

Tranexamic acid modulates the immune response and reduces postsurgical infection rates

Tranexamic acid (TXA) is an antifibrinolytic agent that blocks plasmin formation. Because plasmin is known to promote inflammatory and immunosuppressive responses, we explored the possibility that plasmin-mediated immunosuppression in patients undergoing cardiac surgery can be directly reversed by TXA and decrease postoperative infection rates. The modulatory effect of TXA on inflammatory cytokine levels and on innate immune cell activation were evaluated with multiplex enzyme-linked immunosorbent assay and flow cytometry, respectively. Postoperative infection rates were determined in patients undergoing cardiac surgery and randomized to TXA (ACTRN12605000557639; http://www.anzca.edu.au). We demonstrate that TXA-mediated plasmin blockade modulates the immune system and reduces surgery-induced immunosuppression in patients following cardiac surgery. TXA enhanced the expression of immune-activating markers while reducing the expression of immunosuppressive markers on multiple myeloid and lymphoid cell populations in peripheral blood. TXA administration significantly reduced postoperative infection rates, despite the fact that patients were being administered prophylactic antibiotics. This effect was independent of the effect of TXA at reducing blood loss. TXA was also shown to exert an immune-modulatory effect in healthy volunteers, further supporting the fibrin-independent effect of TXA on immune function and indicating that baseline plasmin levels contribute to the regulation of the immune system in the absence of any comorbidity or surgical trauma. Finally, the capacity of TXA to reduce infection rates, modulate the innate immune cell profile, and generate an antifibrinolytic effect overall was markedly reduced in patients with diabetes, demonstrating for the first time that the diabetic condition renders patients partially refractory to TXA.

Damage control resuscitation

The United States Navy originally utilized the concept of damage control to describe the process of prioritizing the critical repairs needed to return a ship safely to shore during a maritime emergency. To pursue a completed repair would detract from the goal of saving the ship. This concept of damage control management in crisis is well suited to the care of the critically ill trauma patient, and has evolved into the standard of care. Damage control resuscitation is not one technique, but, rather, a group of strategies which address the lethal triad of coagulopathy, acidosis, and hypothermia. In this article, we describe this approach to trauma resuscitation and the supporting evidence base.

Current state of play regarding dental extractions in patients with haemophilia: Consensus or evidence-based practice? A review of the literature

Due to the global prevalence of oral disease, tooth extraction is the most common surgical procedure required in general population thus likely to be similarly common in patients with haemophilia, especially those in older age and those living in countries with restricted resources. There are little or no consensus about optimal level and duration of factor replacement (FRP) therapy required to prevent bleeding complication following surgery and low levels of evidence to inform protocols and guidelines. The goal of this article was to review the literature regarding haematological treatment protocols and to assess their effectiveness in prevention of bleeding complications during and after tooth extractions in people with haemophilia. A total number of 29 articles were identified. Only two of the studies were randomized controlled trials, and meta-analysis was not possible. Significant heterogeneity regarding haematological regimes, dental surgical procedures, disease severity and sample size of published studies which are unable to reliably inform the provision of safe dental surgery was noted. Based on the haematological regimens, all studies were classified into one of three groups: pre- and postoperative FRP or DDAVP, single preoperative FRP or DDAVP, and no FRP treatment. The overall reported bleeding rate in case of both pre- and postoperative FRP and single dose FRP preoperative is similar, 11.9% and 11.4%, respectively, indicating that minimizing the use of clotting factor concentrate is possible if proper local haemostatic measures are provided. Strictly designed prospective studies with higher number of patients are necessary to get firm conclusions about optimal FRP treatment required to prevent bleeding complications during and after oral surgery in patients with haemophilia.

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.

Introduction of a standardised protocol, including systematic use of tranexamic acid, for management of severe adult trauma patients in a low-resource setting: the MSF experience from Port-au-Prince, Haiti

BACKGROUND

Bleeding is an important cause of death in trauma victims. In 2010, the CRASH-2 study, a multicentre randomized control trial on the effect of tranexamic acid (TXA) administration to trauma patients with suspected significant bleeding, reported a decreased mortality in randomized patients compared to placebo. Currently, no evidence on the use of TXA in humanitarian, low-resource settings is available. We aimed to measure the hospital outcomes of adult patients with severe traumatic bleeding in the Médecins Sans Frontières Tabarre Trauma Centre in Port-au-Prince, Haiti, before and after the implementation of a Massive Haemorrhage protocol including systematic early administration of TXA.

METHODS

Patients admitted over comparable periods of four months (December2015- March2016 and December2016 - March2017) before and after the implementation of the Massive Haemorrhage protocol were investigated. Included patients had blunt or penetrating trauma, a South Africa Triage Score ≥ 7, were aged 18-65 years and were admitted within 3 h from the traumatic event. Measured outcomes were hospital mortality and early mortality rates, in-hospital time to discharge and time to discharge from intensive care unit.

RESULTS

One-hundred and sixteen patients met inclusion criteria. Patients treated after the introduction of the Massive Haemorrhage protocol had about 70% less chance of death during hospitalization compared to the group "before" (adjusted odds ratio 0.3, 95%confidence interval 0.1-0.8). They also had a significantly shorter hospital length of stay (p = 0.02).

CONCLUSIONS

Implementing a Massive Haemorrhage protocol including early administration of TXA was associated with the reduced mortality and hospital stay of severe adult blunt and penetrating trauma patients in a context with poor resources and limited availability of blood products.

Antifibrinolytic therapy for preventing oral bleeding in patients with haemophilia or Von Willebrand disease undergoing minor oral surgery or dental extractions

BACKGROUND

Minor oral surgery or dental extractions (oral or dental procedures) are widely performed and can be complicated by hazardous oral bleeding, especially in people with an inherited bleeding disorder such as haemophilia or Von Willebrand disease (VWD). The amount and severity of singular bleedings depend on disease-related factors, such as the severity of the haemophilia, both local and systemic patient factors (such as periodontal inflammation, vasculopathy or platelet dysfunction) and intervention-related factors (such as the type and number of teeth extracted or the dimension of the wound surface). Similar to local haemostatic measures and suturing, antifibrinolytic therapy is a cheap, safe and potentially effective treatment to prevent bleeding complications in individuals with bleeding disorders undergoing oral or dental procedures. However, a systematic review of trials reporting outcomes after oral surgery or a dental procedure in people with an inherited bleeding disorder, with or without, the use of antifibrinolytic agents has not been performed to date. This is an update of a previously published Cochrane Review.

OBJECTIVES

Primarily, we aim to assess the efficacy of antifibrinolytic agents to prevent bleeding complications in people with haemophilia or VWD undergoing oral or dental procedures.Secondary objectives are to assess if antifibrinolytic agents can replace or reduce the need for clotting factor concentrate therapy in people with haemophilia or VWD and to establish the effects of these agents on bleeding in oral or dental procedures for each of these patient populations.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, compiled from electronic database searches of the Cochrane Central Register of Controlled Trials (CENTRAL), of MEDLINE and from handsearching of journals and conference abstract books. We additionally searched the reference lists of relevant articles and reviews. We searched PubMed, Embase, Cinahl and the Cochrane Library. Additional searches were performed in ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP).Date of last search of the Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register: 01 March 2019.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials in people with haemophilia or VWD undergoing oral or dental procedures using antifibrinolytic agents (tranexamic acid or epsilon aminocaproic acid (EACA)) to prevent perioperative bleeding compared to no intervention or usual care with or without placebo.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the titles and abstracts of all identified articles. Full texts were obtained for potentially relevant abstracts and two authors independently assessed these for inclusion based on the selection criteria. A third author verified trial eligibility. Two authors independently performed data extraction and risk of bias assessments using standardised forms.

MAIN RESULTS

While there were no eligible trials in people with VWD identified, two randomised, double-blind, placebo-controlled trials (total of 59 participants) in people with haemophilia undergoing dental extraction were included. One trial of tranexamic acid published in 1972 included 28 participants with mild, moderate or severe haemophilia A and B and one of EACA published in 1971 included 31 people with haemophilia with factor VIII or factor IX levels less than 15%. Overall, the two included trials showed a beneficial effect of tranexamic acid and EACA, administered systemically, in reducing the number of bleedings, the amount of blood loss and the need for therapeutic clotting factor concentrates. Regarding postoperative bleeding, the tranexamic acid trial showed a risk difference (RD) of -0.64 (95% confidence interval (CI) -0.93 to - 0.36) and the EACA trial a RD of -0.50 (95% CI 0.77 to -0.22). The combined RD of both trials was -0.57 (95% CI -0.76 to -0.37), with the quality of the evidence (GRADE) for this outcome is rated as moderate. Side effects occurred once and required stopping EACA (combined RD of -0.03 (95% CI -0.08 to 0.13). There was heterogeneity between the two trials regarding the proportion of people with severe haemophilia included, the concomitant standard therapy and fibrinolytic agent treatment regimens used. We cannot exclude that a selection bias has occurred in the EACA trial, but overall the risk of bias appeared to be low for both trials.

AUTHORS' CONCLUSIONS

Despite the discovery of a beneficial effect of systemically administered tranexamic acid and EACA in preventing postoperative bleeding in people with haemophilia undergoing dental extraction, the limited number of randomised controlled trials identified, in combination with the small sample sizes and heterogeneity regarding standard therapy and treatment regimens between the two trials, do not allow us to conclude definite efficacy of antifibrinolytic therapy in oral or dental procedures in people with haemophilia. No trials were identified in people with VWD.

Increased urokinase and consumption of α2 -antiplasmin as an explanation for the loss of benefit of tranexamic acid after treatment delay

Essentials Delayed treatment with tranexamic acid results in loss of efficacy and poor outcomes. Increasing urokinase activity may account for adverse effects of late tranexamic acid treatment. Urokinase + tranexamic acid produces plasmin in plasma or blood and disrupts clotting. α2 -Antiplasmin consumption with ongoing fibrinolysis increases plasmin-induced coagulopathy. SUMMARY: Background Tranexamic acid (TXA) is an effective antifibrinolytic agent with a proven safety record. However, large clinical trials show TXA becomes ineffective or harmful if treatment is delayed beyond 3 h. The mechanism is unknown but urokinase plasminogen activator (uPA) has been implicated. Methods Inhibitory mechanisms of TXA were explored in a variety of clot lysis systems using plasma and whole blood. Lysis by tissue plasminogen activator (tPA), uPA and plasmin were investigated. Coagulopathy was investigated using ROTEM and activated partial thromboplastin time (APTT). Results IC50 values for antifibrinolytic activity of TXA varied from < 10 to > 1000 μmol L-1 depending on the system, but good fibrin protection was observed in the presence of tPA, uPA and plasmin. However, in plasma or blood, active plasmin was generated by TXA + uPA (but not tPA) and coagulopathy developed leading to no or poor clot formation. The extent of coagulopathy was sensitive to available α2 -antiplasmin. No clot formed with plasma containing 40% normal α2 -antiplasmin after short incubation with TXA + uPA. Adding purified α2 -antiplasmin progressively restored clotting. Plasmin could be inhibited by aprotinin, IC50 = 530 nmol L-1 , in plasma. Conclusions Tranexamic acid protects fibrin but stimulates uPA activity and slows inhibition of plasmin by α2 -antiplasmin. Plasmin proteolytic activity digests fibrinogen and disrupts coagulation, exacerbated when α2 -antiplasmin is consumed by ongoing fibrinolysis. Additional direct inhibition of plasmin by aprotinin may prevent development of coagulopathy and extend the useful time window of TXA treatment.

Antifibrinolytic therapy for preventing oral bleeding in people on anticoagulants undergoing minor oral surgery or dental extractions

BACKGROUND

Individuals on continuous treatment with vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs) are at increased risk of bleeding complications during and after oral or dental procedures. Anticoagulant treatment is preferably continued at the same dose, since dose reduction or discontinuation of treatment is associated with an increased risk of thromboembolism. The use of haemostatic measures during or after the procedure (or both) could enable continuation of the oral anticoagulant treatment.

OBJECTIVES

We aimed to assess the efficacy of antifibrinolytic agents for preventing bleeding complications in people on oral anticoagulants undergoing minor oral surgery or dental extractions.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Coagulopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. We searched PubMed, Embase and the Cochrane Library. Additional searches were performed using ClinicalTrials.gov, the International Clinical Trials Registry Platform (ICTRP), the CINAHL database of nursing and allied health services, the open access ProQuest dissertation database, papers and reports from the American College of Clinical Pharmacy (ACCP) and abstract books from annual scientific conferences.Date of last search: 04 January 2018.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials in people on continuous treatment with VKAs or DOACs undergoing oral or dental procedures using antifibrinolytic agents (tranexamic acid (TXA) or epsilon aminocaproic acid) to prevent perioperative bleeding compared to no intervention or usual care with or without placebo.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the titles and abstracts of all identified articles. Full texts were obtained from potentially relevant abstracts and two authors independently assessed these for inclusion based of the selection criteria. A third author verified trial eligibility. Two authors independently performed data extraction and risk of bias assessments using standardized forms. The quality of the evidence was assessed using GRADE.

MAIN RESULTS

No eligible trials in people on continuous treatment with DOACs undergoing oral or dental procedures were identified.Three randomised trials and one quasi-randomised trial (follow-up in all was seven days) in people on continuous treatment with VKAs were included with a total of 253 participants (mean age 60 years). Two trials published in 1989 and 1993 compared the antifibrinolytic agent TXA with placebo in people using VKAs. Two other trials were published in 1999 and 2015 and compared TXA with gelatin sponge and sutures, and dry gauze compression, respectively. In all included trials, those who were treated with VKAs had international normalised ratio (INR) values within the therapeutic range and TXA was applied locally, not systemically.The two trials from 1989 and 1993 comparing TXA with placebo showed a statistically significant beneficial effect regarding the number of major postoperative bleeding episodes requiring intervention, with a pooled risk difference (RD) of -0.25 (95% confidence interval (CI) -0.36 to -0.14) (128 participants) (moderate-quality evidence). For the two trials that compared TXA with either gelatin sponge and sutures or with dry gauze compression, there was no difference between the TXA and the standard care group, RD 0.02 (95% CI -0.07 to 0.11) (125 participants) (moderate-quality evidence). The combined RD of all included trials was -0.13 (95% CI -0.30 to 0.05) (moderate-quality evidence). There were no side effects of antifibrinolytic therapy that required treatment withdrawal (128 participants) (moderate-quality evidence). Despite heterogeneity between trials with respect to the different haemostatic measures used in the control groups, the trials were comparable regarding design and baseline participant characteristics.Overall, we considered the risk of bias to be low in the trials comparing TXA with placebo and moderate in the trials comparing TXA with alternative haemostatic measures.

AUTHORS' CONCLUSIONS

Based on the results of this Cochrane Review, there seems to be a beneficial effect of locally applied TXA in preventing oral bleeding in people on continuous treatment with VKAs undergoing minor oral surgery or dental extractions. However, the small number of identified randomised controlled trials, the relatively small number of participants included in the trials and the differences in standard therapy and treatment regimens between trials, do not allow us to conclude definite efficacy of antifibrinolytic therapy in this population.We were unable to identify any eligible trials in people on continuous treatment with DOACs undergoing oral or dental procedures. Therefore, a beneficial effect of antifibrinolytic therapy can currently only be assumed based on data from the people using VKAs.

Abrogating fibrinolysis does not improve bleeding or rFVIIa/rFVIII treatment in a non-mucosal venous injury model in haemophilic rodents

Essentials The efficacy of systemic antifibrinolytics for hemophilic non-mucosal bleeding is undetermined. The effect of systemically inhibiting fibrinolysis in hemophilic mice and rats was explored. Neither bleeding nor the response to factor treatment was improved after inhibiting fibrinolysis. The non-mucosal bleeding phenotype in hemophilia A appears largely unaffected by fibrinolysis.

SUMMARY

Background Fibrinolysis may exacerbate bleeding in patients with hemophilia A (HA). Accordingly, antifibrinolytics have been used to help maintain hemostatic control. Although antifibrinolytic drugs have been proven to be effective in the treatment of mucosal bleeds in the oral cavity, their efficacy in non-mucosal tissues remain an open question of significant clinical interest. Objective To determine whether inhibiting fibrinolysis improves the outcome in non-mucosal hemophilic tail vein transection (TVT) bleeding models, and to determine whether a standard ex vivo clotting/fibrinolysis assay can be used as a predictive surrogate for in vivo efficacy. Methods A highly sensitive TVT model was employed in hemophilic rodents with a suppressed fibrinolytic system to examine the effect of inhibiting fibrinolysis on bleeding in non-mucosal tissue. In mice, induced and congenital hemophilia models were combined with fibrinolytic attenuation achieved either genetically or pharmacologically (tranexamic acid [TXA]). In hemophilic rats, tail bleeding was followed by whole blood rotational thromboelastometry evaluation of the same animals to gauge the predictive value of such assays. Results The beneficial effect of systemic TXA therapy observed ex vivo could not be confirmed in vivo in hemophilic rats. Furthermore, neither intravenously administered TXA nor congenital knockout of the fibrinolytic genes encoding plasminogen or tissue-type plasminogen activator markedly improved the TVT bleeding phenotype or response to factor therapy in hemophilic mice. Conclusions The findings here suggest that inhibition of fibrinolysis is not effective in limiting the TVT bleeding phenotype of HA rodents in non-mucosal tissues.

End Stage Renal Disease: Not a Contraindication for Minor Oral Surgery-Protocol for the Management of Oral Surgery patients with ESRD on Hemodialysis

OBJECTIVE

To describe a safe and effective protocol for the management of patients with end stage renal disease (ESRD) undergoing minor oral surgery.

SUBJECTS AND METHODS

A prospective cohort study was conducted on all patients with ESRD who were referred for dental consultation. A definite protocol was designed in consultation with the nephrologist to minimize the risk of bleeding and wound healing complications during and after the minor surgical procedures. 36 patients consented for the protocol to be followed while 4 patients did not comply with the protocol and in 2 cases the protocol could be followed. The intra operative, post operative bleeding, and the wound healing were assessed in these patients.

RESULTS

36 patients had uneventful extractions as the blood pressure was brought down to pre hypertensive stage following the protocol. 4 patients who did not comply with the protocol had episodes of bleeding in the post operative period. There were two special scenarios where additional precautions had to be taken have been discussed. The wound healing was satisfactory in all these patients.

CONCLUSION

The protocol discussed in this article helps us provide safe minor oral surgical treatment in patients with ESRD.

Preventing perioperative bleeding in patients with inherited bleeding disorders

Data sourcesCochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, a regularly updated database informed by trials identified within electronic databases including MEDLINE. Further defined searches were undertaken in PubMed, Embase, The Cochrane Library, ClinicalTrials.gov and WHO International Clinical Trials Registry Platform. Additional hand searching of relevant journals and books of conference proceedings was undertaken.Study selectionRandomised and quasi-randomised controlled trials in people of all ages with haemophilia or VWD undergoing oral or dental procedures using antifibrinolytic agents (tranexamic acid (TXA) or epsilon aminocaproic acid (EACA)) to prevent perioperative bleeding compared to no intervention with or without placebo.Data extraction and synthesisTwo authors independently assessed identified publications for inclusion based on defined selection criteria. The two authors performed data extraction and risk of bias assessments using standardised forms and the Cochrane risk of bias tools. A third author, deemed to have particular subject expertise, verified eligibility of inclusion.ResultsOne randomised, double-blinded placebo controlled trial and one quasi-randomised trial were included. A total of 59 participants with haemophilia undergoing dental extraction were involved. Both trials evidenced a notable reduction in post-operative bleeding following dental extraction when either TXA or EACA were used, in addition to routine preoperative factor replacement, when compared to placebo. The number of post-operative bleeds, amount of blood loss and the need for additional clotting factors were reduced in the groups receiving antifibrinolytic therapy. No eligible trials in people with VWD were identified.ConclusionsLow quality evidence exists to support the use of adjuvant antifibrinolytic therapy to reduce perioperative bleeding in patients with haemophilia undergoing dental extraction. The limited number of trials identified (N=2), minimal sample size (N=28, N=31) and historic nature of the studies, originating from the 1970s, in addition to study heterogeneity and subsequent selection bias results in a low quality evidence grade for recommending adjuvant antifibrinolytic therapy. There is no clear indication to alter current practice utilising antifibrinolytic therapy to manage patients with haemophilia undergoing dental surgery in accordance with internationally accepted guidelines. However, further research with standardised study deigns would be welcomed in order to enhance the evidence base in the management of people with haemophilia and VWD.

Bleeding related to disturbed fibrinolysis

The components and reactions of the fibrinolysis system are well understood. The pathway has fewer reactants and interactions than coagulation, but the generation of a complete quantitative model is complicated by the need to work at the solid‐liquid interface of fibrin. Diagnostic tools to detect disease states due to malfunctions in the fibrinolysis pathway are also not so well developed as is the case with coagulation. However, there are clearly a number of inherited or acquired pathologies where hyperfibrinolysis is a serious, potentially life‐threatening problem and a number of antifibrinolytc drugs are available to treat hyperfibrinolysis. These topics will be covered in the following review.

Antifibrinolytic therapy for preventing oral bleeding in patients with haemophilia or Von Willebrand disease undergoing minor oral surgery or dental extractions

BACKGROUND

Minor oral surgery or dental extractions (oral or dental procedures) are widely performed and can be complicated by hazardous oral bleeding, especially in people with an inherited bleeding disorder such as haemophilia or Von Willebrand disease. The amount and severity of singular bleedings depend on disease-related factors, such as the severity of the haemophilia, both local and systemic patient factors (such as periodontal inflammation, vasculopathy or platelet dysfunction) and intervention-related factors (such as the type and number of teeth extracted or the dimension of the wound surface). Similar to local haemostatic measures and suturing, antifibrinolytic therapy is a cheap, safe and potentially effective treatment to prevent bleeding complications in individuals with bleeding disorders undergoing oral or dental procedures. However, a systematic review of trials reporting outcomes after oral surgery or a dental procedure in people with an inherited bleeding disorder, with or without, the use of antifibrinolytic agents has not been performed to date.

OBJECTIVES

The primary objective was to assess the efficacy of local or systemic use of antifibrinolytic agents to prevent bleeding complications in people with haemophilia or Von Willebrand disease undergoing oral or dental procedures. Secondary objectives were to assess if antifibrinolytic agents can replace or reduce the need for clotting factor concentrate therapy in people with haemophilia or Von Willebrand disease and to further establish the effects of these agents on bleeding in oral or dental procedures for each of these populations.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, compiled from electronic database searches of the Cochrane Central Register of Controlled Trials (CENTRAL), of MEDLINE and from handsearching of journals and conference abstract books. We additionally searched the reference lists of relevant articles and reviews. We searched PubMed, Embase and The Cochrane Library. Additional searches were performed in ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP).Date of last search of the Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register: 14 December 2015.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials in people with haemophilia or Von Willebrand disease undergoing oral or dental procedures using antifibrinolytic agents (tranexamic acid or epsilon aminocaproic acid) to prevent perioperative bleeding compared to no intervention or usual care with or without placebo.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the titles and abstracts of all identified articles. Full texts were obtained for potentially relevant abstracts and two authors independently assessed these for inclusion based on the selection criteria. A third author verified trial eligibility. Two authors independently performed data extraction and risk of bias assessments using standardized forms.

MAIN RESULTS

While there were no eligible trials in people with Von Willebrand disease identified, two randomised, double-blind, placebo-controlled trials (total of 59 participants) in people with haemophilia undergoing dental extraction were included. One trial of tranexamic acid published in 1972 included 28 participants with mild, moderate or severe haemophilia A and B and one of epsilon aminocaproic acid published in 1971 included 31 people with haemophilia with factor VIII or factor IX levels less than 15%. Overall, the two included trials showed a beneficial effect of tranexamic acid and EACA, administered systemically, in reducing the number of bleedings, the amount of blood loss and the need for therapeutic clotting factor concentrates. Regarding postoperative bleeding, the tranexamic acid trial showed a risk difference of -0.64 (95% confidence interval -0.93 to - 0.36) and the EACA trial a risk difference of -0.50 (95% confidence interval 0.77 to -0.22). The combined risk difference of both trials was -0.57 (95% confidence interval -0.76 to -0.37), with the quality of the evidence (GRADE) for this outcome is rated as moderate. Side effects occurred once and required stopping epsilon aminocaproic acid (combined risk difference of -0.03 (95% CI -0.08 to 0.13). There was heterogeneity between the two trials regarding the proportion of people with severe haemophilia included, the concomitant standard therapy and fibrinolytic agent treatment regimens used. We cannot exclude that a selection bias has occurred in the epsilon aminocaproic acid trial, but overall the risk of bias appeared to be low for both trials.

AUTHORS' CONCLUSIONS

Despite the discovery of a beneficial effect of systemically administered tranexamic acid and epsilon aminocaproic acid in preventing postoperative bleeding in people with haemophilia undergoing dental extraction, the limited number of randomised controlled trials identified, in combination with the small sample sizes and heterogeneity regarding standard therapy and treatment regimens between the two trials, do not allow us to conclude definite efficacy of antifibrinolytic therapy in oral or dental procedures in people with haemophilia. No trials were identified in people with Von Willebrand disease.

Treatment for preventing bleeding in people with haemophilia or other congenital bleeding disorders undergoing surgery

BACKGROUND

In people with haemophilia or other congenital bleeding disorders undergoing surgical interventions, haemostatic treatment is needed in order to correct the underlying coagulation abnormalities and minimise the bleeding risk. This treatment varies according to the specific haemostatic defect, its severity and the type of surgical procedure. The aim of treatment is to ensure adequate haemostatic coverage for as long as the bleeding risk persists and until wound healing is complete.

OBJECTIVES

To assess the effectiveness and safety of different haemostatic regimens (type, dose and duration, modality of administration and target haemostatic levels) administered in people with haemophilia or other congenital bleeding disorders for preventing bleeding complications during and after surgical procedures.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews.Date of the last search: 20 November 2014.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing any hemostatic treatment regimen to no treatment or to another active regimen in children and adults with haemophilia or other congenital bleeding disorders undergoing any surgical intervention.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials (eligibility and risks of bias) and extracted data. Meta-analyses were performed on available and relevant data.

MAIN RESULTS

Of the 16 identified trials, four (112 participants) were eligible for inclusion.Two trials evaluated 59 people with haemophilia A and B undergoing 63 dental extractions. Trials compared the use of a different type (tranexamic acid or epsilon-aminocaproic acid) and regimen of antifibrinolytic agents as haemostatic support to the initial replacement treatment. Neither trial specifically addressed mortality (one of this review's primary outcomes); however, in the frame of safety assessments, no fatal adverse events were reported. The second primary outcome of blood loss was assessed after surgery and these trials showed the reduction of blood loss and requirement of post-operative replacement treatment in people receiving antifibrinolytic agents compared with placebo. The remaining primary outcome of need for re-intervention was not reported by either trial.Two trials reported on 53 people with haemophilia A and B with inhibitors treated with different regimens of recombinant activated factor VII (rFVIIa) for haemostatic coverage of 33 major and 20 minor surgical interventions. Neither of the included trials specifically addressed any of the review's primary outcomes (mortality, blood loss and need for re-intervention). In one trial a high-dose rFVIIa regimen (90 μg/kg) was compared with a low-dose regimen (35 μg/kg); the higher dose showed increased haemostatic efficacy, in particular in major surgery, with shorter duration of treatment, similar total dose of rFVIIa administered and similar safety levels. In the second trial, bolus infusion and continuous infusion of rFVIIa were compared, showing similar haemostatic efficacy, duration of treatment and safety.

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomised controlled trials to assess the most effective and safe haemostatic treatment to prevent bleeding in people with haemophilia or other congenital bleeding disorders undergoing surgical procedures. Ideally large, adequately powered, and well-designed randomised controlled trials would be needed, in particular to address the cost-effectiveness of such demanding treatments in the light of the increasing present economic constraints, and to explore the new challenge of ageing patients with haemophilia or other congenital bleeding disorders. However, performing such trials is always a complex task in this setting and presently does not appear to be a clinical and research priority. Indeed, major and minor surgeries are effectively and safely performed in these individuals in clinical practice, with the numerous national and international recommendations and guidelines providing regimens for treatment in this setting mainly based on data from observational, uncontrolled studies.

Tranexamic acid--an old drug still going strong and making a revival

Experience with tranexamic acid, an indirect fibrinolytic inhibitor, started as soon as it was released from Shosuke Okamoto's lab in the early 1960s. It was first prescribed to females with heavy menstrual blood loss and to patients with hereditary bleeding disorders. Soon the indications were widened to elective surgery because of its blood saving effects. Contraindications are few, most important is ongoing venous or arterial thrombosis and allergy to tranexamic acid, and the doses has to be reduced in renal insufficiency. In randomized controlled trials, however, patients with other risk factors are excluded as well (patients with history of cardiovascular disease, thromboembolism, bleeding diathesis, renal failure with creatinine >250μmol/L, pregnancy, and patients on treatment with anticoagulants). Recent meta-analyses of several randomized controlled trials in orthopedic arthroplasty have shown that tranexamic acid reduces peri- and postoperative blood loss, blood transfusion requirements and reoperations caused by bleedings. In general, the preoperative dose was 10-15mg/kg i.v. (or 1g), followed or not, by one or two doses, some as continuous infusion i.v. To validate relationship between dose and effect more data are needed. No evidence was found of increased thromboembolic accidents or other adverse events in the patients on tranexamic acid compared to the control groups. In major cardiac surgery tranexamic acid has been used in a large number of controlled trials with various dosing schemes in which the highest dosages seem to be associated with neurotoxicity; therefore a maximum total dose of 100mg/kg especially in patients over 50years of age is recommended by ISMICS (International Society for Minimally Invasive Cardiothoracic Surgery). Other indications for tranexamic acid are reviewed here as well. In recent years the extensive trial in severe trauma with massive bleedings using tranexamic acid was presented, CRASH-2 (Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage) comprising more than 20,000 patients. It showed that the survival was increased when tranexamic acid was given early after the accident compared to placebo; further studies are taking place is this field to get more information. Of utmost importance is the ongoing WOMAN (World Maternal Antifibrinolytic) a randomized, double-blind, placebo controlled trial among 15,000 with clinical diagnosis of postpartum haemorrhage bearing in mind that each year a large number of women in low and middle income countries, die from causes related to childbirth. In summary, we consider tranexamic acid is a drug of great value to reduce almost any kind of bleeding, it is cheap and convenient to use and has principally few contraindications. It may be added, that tranexamic acid is included in the WHOs list of essential medicines.

Topical tranexamic acid reduces transfusion rates in total hip and knee arthroplasty

The efficaciousness of topical tranexamic acid use at the end of knee arthroplasty surgery to reduce blood loss and transfusion requirements has previously been shown. The aim of this study was to retrospectively assess the effectiveness of topical tranexamic acid use, comparing 155 patients undergoing hip and knee arthroplasty surgery in which tranexamic acid was routinely used, to a group of 149 patients from a similar time frame prior to the introduction of tranexamic acid use. The transfusion rate fell from 19.3% to 2.3% for hip arthroplasty patients and from 13.1% to 0% for knee arthroplasty patients; these differences were significant. We also found significant reductions in haemoglobin loss, blood loss and length of stay of 8 g/L, 244 mL and 1.0 days respectively for hip arthroplasties and 15 g/L, 527 mL and 1.2 days respectively for knee arthroplasties following the introduction of tranexamic acid.

Tranexamic Acid Tamponade to Control Postoperative Surgical Hemorrhage

When preparing for oral surgery, patients taking anticoagulants usually should not discontinue their medication because of the risk of a thromboembolic event. The therapeutic effect of many anticoagulants is not readily measured, so preoperatively, the surgeon cannot know the true risk for postoperative hemorrhage. The risk of a thromboembolic event usually outweighs the concerns of controlling postoperative hemorrhage. Hemophilia patients are also at risk for postoperative bleeding. Single extractions probably do not pose a serious risk for postoperative hemorrhage. However, when a mucogingival flap is raised in these patients, there may be prolonged bleeding. Surgical sponges saturated with aqueous tranexamic acid solution and compressed onto the bleeding site with biting pressure may stop bleeding. Bleeding was stopped in the case example presented here after three 10-minute compressions over 30 minutes in a patient taking aspirin and clopidogrel for a previous thromboembolic event and a metal coronary stent. The clot formed is very fragile and is prone to bleeding, so it should not be disturbed. This technique needs to be studied for efficacy.

Tranexamic acid: a review of its use in the treatment of hyperfibrinolysis

Tranexamic acid, a synthetic derivative of the amino acid lysine, is an antifibrinolytic agent that acts by binding to plasminogen and blocking the interaction of plasmin(ogen) with fibrin, thereby preventing dissolution of the fibrin clot. Tranexamic acid (Transamin®) is indicated in Japan for use in certain conditions with abnormal bleeding or bleeding tendencies in which local or systemic hyperfibrinolysis is considered to be involved. This article reviews the efficacy and tolerability of tranexamic acid in conditions amenable to antifibrinolytic therapy and briefly overviews the pharmacological properties of the drug. In large, randomized controlled trials, tranexamic acid generally significantly reduced perioperative blood loss compared with placebo in a variety of surgical procedures, including cardiac surgery with or without cardiopulmonary bypass, total hip and knee replacement and prostatectomy. In many instances, tranexamic acid also reduced transfusion requirements associated with surgery. It also reduced blood loss in gynaecological bleeding disorders, such as heavy menstrual bleeding, postpartum haemorrhage and bleeding irregularities caused by contraceptive implants. Tranexamic acid significantly reduced all-cause mortality and death due to bleeding in trauma patients with significant bleeding, particularly when administered early after injury. It was also effective in traumatic hyphaema, gastrointestinal bleeding and hereditary angioneurotic oedema. While it reduces rebleeding in subarachnoid haemorrhage, it may increase ischaemic complications. Pharmacoeconomic analyses predicted that tranexamic acid use in surgery and trauma would be very cost effective and potentially life saving. In direct comparisons with other marketed agents, tranexamic acid was at least as effective as ε-aminocaproic acid and more effective than desmopressin in surgical procedures. It was more effective than desmopressin, etamsylate, flurbiprofen, mefenamic acid and norethisterone, but less effective than the levonorgestrel-releasing intra-uterine device in heavy menstrual bleeding and was as effective as prednisolone in traumatic hyphaema. Tranexamic acid was generally well tolerated. Most adverse events in clinical trials were of mild or moderate severity; severe or serious events were rare. Therefore, while high-quality published evidence is limited for some approved indications, tranexamic acid is an effective and well tolerated antifibrinolytic agent.

The effect of ε-aminocaproyl-S-benzyl-L-cysteine on the t-PA activity of human saliva

PURPOSE

The aim of this work was to study the effect of the synthetic antifibrinolytics: ε-aminocaproic acid (EACA), tranexamic acid (AMCHA) and ε-aminocaproyl-S-benzyl-L-cysteine (H-EACA-S-Bzl-L-Cys-OH) on the fibrinolytic activity of saliva in order to obtain new data on the activity of saliva tissue plasminogen activator (t-PA).

MATERIAL AND METHODS

Saliva samples were obtained from healthy volunteers. Saliva, precipitate and supernatant were tested 1hr, 4 hrs and 6hrs after collection. The effect of the synthetic antifibrinolytics was examined with the use of the clot lysis time determination.

RESULTS

All examined compounds inhibited the fibrinolytic activity of saliva 1hr after collection. H-EACA-S-Bzl-L-Cys-OH was the most active inhibitor. After 6 hours in room temperature only this compound showed a certain possibility to prolong the clot lysis time.

CONCLUSIONS

The obtained results may indicate the possibility of the difference in specificity between the activities of t-PA of saliva and recombinant tissue plasminogen activator activities. It may explain the unexpected high inhibitory activity of H-EACA-S-Bzl-L-Cys-OH in our study.

Tranexamic acid combined with recombinant factor VIII increases clot resistance to accelerated fibrinolysis in severe hemophilia A

BACKGROUND

Most patients with severe hemophilia A suffer from a profoundly compromised hemostatic response. In addition to both the delayed and slow development of a clot, previous studies have documented that severe hemophilia A is also associated with reduced clot stability.

OBJECTIVES

We examined whether the clot stability in hemophiliacs could be improved by treatment with tranexamic acid (TXA) in combination with recombinant factor VIII (rFVIII).

PATIENTS/METHODS

Baseline blood samples were obtained from eight males with severe hemophilia A. Thereafter, a bolus injection of rFVIII was administered to increase the functional level of FVIII to approximately 50%. After 10 min, blood was collected followed by an intravenous injection of TXA. A third blood sample was obtained after a further 10 min. Whole blood clotting profiles were determined by thrombelastography using minimal tissue factor activation. Clot formation was assessed by both clot initiation and clot propagation. At clot termination, the maximum clot firmness and area under the elasticity curve were used to illustrate clot stability. Tissue-plasminogen activator was included in those experiments designed to assess clot stability.

RESULTS

As expected, rFVIII increased clot formation, whereas TXA had no effect upon this parameter. Assays including tissue-plasminogen activator revealed that rFVIII increased the maximum clot firmness 3-fold; whereas the presence of TXA induced an additional 4-fold increase. The area under the elasticity curve increased 5-fold after rFVIII and 24-fold after addition of TXA.

CONCLUSIONS

The study demonstrates that simultaneous treatment with TXA and rFVIII significantly improves the clot stability in patients with hemophilia A.

Evaluation of the oral health situation of a group of Egyptian haemophilic children and their re-evaluation following an oral hygiene and diet education programme

Haemophilic children in Egypt have received minimal dental intervention and their dental needs required assessment. The purpose of this study was to assess the oral health needs of a sample (n = 60) of Egyptian haemophilic children (6-12 years), so as to develop, implement and evaluate an oral hygiene education programme over an 8-month period on the experimental group (n = 30) vs. the control group (n = 30). The oral hygiene index simplified (OHI-S) index was used for baseline data and at the end of the study, while DMFS and defs were used to collect caries experience baseline data on each subject. The results showed that the DMFT and deft were significantly higher than those of the non-haemophilic population in Egypt and also higher than those of haemophilic children in developed countries and that the decayed component represented most of the index values. At phase I, the mean value of the OHI-S of experimental and the control groups was 2.67 +/- 0.45 and 2.53 +/- 0.53, respectively, but the difference was not significant (P > 0.05), both values were in the 'fair' category (1.3-3.0). At phase II, the end of the 8 months follow-up period and after the application of a strict oral care programme in the experimental group, there was a significant decrease from 2.67 to 1.20 (P < 0.001), a shift of values occurred from the 'fair' category to the 'good' category (0.1-1.2) while there was no significant difference in the control group. It can be concluded that professional plaque control, education and access to oral hygiene aids is paramount to improve oral health of these children.

Ultra-early Hemostatic Therapy for Acute Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is the least treatable form of stroke, and causes high mortality, severe disability, and a staggering economic burden. ICH accounts for 15% of stroke cases in the United States and Europe, and up to 30% in Asian populations. Computed tomography-based studies suggest that ICH growth within the first few hours of onset is common, and the principal cause of early neurological deterioration. Hematoma volume is also a well-established predictor of 30-day mortality. Intervention with ultra-early hemostatic therapy could minimize or prevent this early dynamic bleeding process, and might improve outcome. Recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) is approved for the treatment of bleeding in patients with hemophilia and inhibitors, but it may also promote hemostasis in patients with normal coagulation by acting locally at the bleeding site without activation of systemic coagulation. In a randomized, double-blind, placebo-controlled trial of 399 ICH patients treated with a single dose of 40, 80, or 160 microg/kg of rFVIIa or placebo within 4 hours of onset, subsequent hematoma growth was reduced by approximately 50% with rFVIIa. This was associated with a significant reduction (38%) in mortality, and improved functional outcomes among survivors. A phase III trial comparing 20 and 80 microg/kg rFVIIa with placebo is now in progress to confirm these results.

Effectiveness in controlling haemorrhage after dental scaling in people with haemophilia by using tranexamic acid mouthwash

AIMS

To compare the effectiveness of tranexamic acid mouthwash (TAMW) in controlling gingival haemorrhage after dental scaling with that of using factor replacement therapy (FRT) prior to dental scaling in people with haemophilia.

DESIGN

Double-blind cross-over randomised control trial.

SETTING

Dedicated hospital dental practice for patients with inherited bleeding disorders.

METHOD

Sixteen patients with haemophilia who required dental scaling participated in this pilot study. The experimental treatment regime (ETR) involved transfusing each patient with saline before scaling both quadrants on one side of the mouth followed by oral rinsing with TAMW four times daily for up to eight days. The control regime (CR) involved giving each patient FRT before scaling the opposite side of the mouth followed by use of a placebo TAMW. Each patient underwent both treatments in a random-ised sequence. Both the operator and the patients were unaware of which were the ETR and CR episodes. On both occasions the patient kept a log book of the rinsing regime and any post-operative bleeding. Additionally, a structured post-treatment telephone interview was conducted to assess the effectiveness and the patient acceptability of the ETR.

RESULTS

Thirteen patients completed the study. No statistically significant difference was found in gingival bleeding and mouthwashing frequencies between the ETR and the CR (p > 0.05). Five patients reported no gingival bleeding with either the ETR or the CR. No patient, using either regime, required extra FRT due to gingival haemorrhage. All subjects found the ETR acceptable and easy and reported feeling safe in using TAMW alone to control gingival bleeding after dental scaling.

CONCLUSION

TAMW use after dental scaling was as effective as using FRT beforehand in controlling gingival haemorrhage for people with haemophilia.

The effect of platelets on fibrin gel structure formed in the presence of recombinant factor VIIa in hemophilia plasma and in plasma from a patient with Glanzmann thrombasthenia

Fibrin gel structure has been shown to be dependent on the thrombin concentration as well as the rate of thrombin generation. Accordingly, factor VIII (FVIII)- and FIX-deficient plasma (hemophilia A and B) form loose fibrin clots with high permeability constants. By adding rFVIIa in vitro to FVIII-deficient plasma containing platelets (frozen and thawed), the fibrin gel permeability constant normalized, indicating that extra rFVIIa (1.2 microg mL(-1) or higher) induced a tight fibrin structure. Thrombin generation is highly dependent on the number of platelets, and in this study it was demonstrated that the addition of rFVIIa (5 microg mL(-1)) normalizes the fibrin gel permeability in samples containing platelets (frozen-thawed) in numbers of at least down to 20 x 10(6) mL(-1). The effect of rFVIIa was not observed when unfrozen platelets instead of frozen-thawed platelets were added. Neither was any effect on the fibrin permeability seen, in the presence of annexin V, known to block the effect of phospholipids on the platelet surface. This indicates an important role of platelet phospholipids for the effect of rFVIIa. A similar effect on the fibrin permeability of rFVIIa was observed when added to platelet-rich plasma from a patient with Glanzmann thrombasthenia. Recombinant FVIIa has been found to induce hemostasis in patients with hemophilia and inhibitors against FVIII/FIX as well as in patients with Glanzmann thrombasthenia, indicating the importance of the formation of a tight fibrin gel structure, more resistant against premature proteolysis, for maintaining hemostasis. In conclusion, the addition of rFVIIa (5 microg mL(-1)) also substantially decreased the permeability constant of fibrin gels formed in FVIII-deficient plasma in the presence of low numbers of frozen-thawed platelets (down to 20 x 10(6) mL(-1)). A similar pattern was obtained in plasma from a Glanzmann patient. No effect was found in the presence of unfrozen instead of frozen-thawed platelets. Annexin V blocked any effect of rFVIIa. A normalization of the overall fibrinolysis potential (OFP) during the same condition supports the effect of rFVIIa on the fibrin permeability in the presence of a limited number of platelets.

Diagnosis and treatment of von Willebrand disease

Von Willebrand disease (VWD) is the most common bleeding disorder; it is believed to occur in approximately 1% to 2% of the population. Mucocutaneous and surgical hemorrhage in affected individuals is caused by quantitative and qualitative defects in von Willebrand factor (VWF), a large, multimeric protein that supports platelet adhesion and aggregation in the initiation of hemostasis at the time of vascular injury and functions as a carrier protein for factor VIII in the circulation. Advances in cellular and molecular biology have led to improved understanding of the pathophysiology of the disorder and development of a classification scheme that is based on quantitative and qualitative defects. Effective treatment is dependent on an accurate diagnosis using specific assays of VWF that define the various defects.