Tranexamic acid, a widely used antifibrinolytic agent, causes convulsions by a gamma-aminobutyric acid(A) receptor antagonistic effect

Efficacy and safety of tranexamic acid in acute traumatic brain injury: A meta-analysis of randomized controlled trials

INTRODUCTION

Tranexamic acid (TXA) holds a pivotal role in the therapeutic approach to traumatic conditions. Nevertheless, its precise influence on diminishing mortality and limiting the progression of intracranial hemorrhage (ICH) during the treatment of traumatic brain injury (TBI) remains indeterminate.

METHODS

PubMed, EMBASE, Cochrane Library, and Web of Science were searched for randomized controlled trials that compared TXA and a placebo in adults with TBI up to September 31, 2023. Two authors independently abstracted the data and assessed the quality of evidence. Additionally, subgroup analyses were performed to assess outcomes with low heterogenety.

RESULTS

Our search strategy yielded 11,299 patients from 11 studies. The result showed that TXA had no effect on mortality (RR 0.93 [0.86, 1.00], p = 0.06; I2: 0%, p = 0.79), poor clinical outcomes (RR 0.92 [0.78, 1.09], p = 0.34; I2: 0%, p = 0.40), adverse events (RR 0.94 [0.83, 1.07], p = 0.34; I2: 48%, p = 0.10), vascular occlusive events (RR 0.85 [0.68, 1.06], p = 0.16; I2: 32%, p = 0.22), pulmonary embolism (RR 0.76 [0.47, 1.22], p = 0.26; I2: 0%, p = 0.83), seizure (RR 1.11 [0.92, 1.35], p = 0.27; I2: 0%, p = 0.49) and hemorrhagic complications (RR 0.78 [0.55, 1.09], p = 0.14; I2: 0%, p = 0.42). TXA might reduce the rate of hemorrhagic expansion (RR 0.83 [0.70, 0.99], p = 0.03; I2: 18%, p = 0.29) and mean hemorrhage volume (SMD -0.39 [-0.60, -0.18], p <0.001; I2: 44%, p = 0.13).When the time interval from symptom onset to treatment was <3 h, TXA reduced mean hemorrhage volume (SMD -0.51 [-0.81, -0.20], p = 0.001; I2: 0%, p = 0.94).

CONCLUSIONS

TXA did not elevate the risk of adverse event, however, the lack of reduction in mortality and the poor clinical outcomes constrain the value of clinical application. Early administration of TXA (within 3 h) may significantly decrease the likelihood of ICH growth in patients with TBI.

Safety assessment of tranexamic acid: real-world adverse event analysis from the FAERS database

Background

In recent years, with the continuous expansion of the application scope of Tranexamic acid (TXA), its usage has surged. Despite numerous studies demonstrating its powerful efficacy, concerns regarding its adverse reactions persist, necessitating comprehensive safety assessment. This study analyzed real-world data from the U.S. Food and Drug Administration to investigate TXA-related adverse events, aiming to elucidate its safety and optimize patient treatment.

Methods

The adverse drug event data concerning TXA from 2004 Q1 to 2023 Q3 were collected. Following data standardization, a variety of signal quantification techniques, including the reporting odds ratios, proportional reporting ratios, Bayesian confidence propagation neural network, and empirical Bayes geometric mean were used for analysis.

Results

After analyzing 16,692,026 adverse event reports, a total of 1,574 cases of adverse events related to TXA were identified, spanning 23 system organ classes and 307 preferred terms. In addition to the common thrombosis-related Vascular disorders (n = 386) and Cardiac disorders (n = 377), adverse reactions in the Nervous system disorders category were also observed (n = 785), including Myoclonus (n = 70), Status epilepticus (n = 43), and Myoclonic epilepsy (n = 17). Furthermore, this study uncovered adverse effects such as Renal cortical necrosis, Hepatic cyst rupture, and Vascular stent stenosis, which were not previously mentioned in the instructions. Although these occurred infrequently, they exhibited high signal strength. Both Retinal artery occlusion and Vascular stent thrombosis disorder were frequent and exhibited high signal strength as well. It is worth noting that 78 cases of adverse reactions were caused by confusion between incorrect product administration.

Conclusion

Our research suggests that TXA has some adverse reactions that are being overlooked. As a cornerstone medication in hemorrhage treatment, it's crucial to monitor, identify, and address these adverse reactions effectively.

Safety and effectiveness of Evicel® fibrin sealant as an adjunct to sutured dural repair in children undergoing cranial neurosurgery

PURPOSE

Cerebrospinal fluid (CSF) leakage is a challenging complication of intradural cranial surgery, and children are particularly at risk. The use of dural sealants confers protection in adults, but pediatric studies are scarce. We evaluated the safety and efficacy of Evicel® fibrin sealant as an adjunct to primary dural suturing in children undergoing cranial surgery.

METHODS

A multicenter trial prospectively enrolled pediatric subjects (< 18 years) undergoing cranial neurosurgery who, upon completion of primary sutured dural repair, experienced CSF leakage. As agreed by the EMA Evicel® Pediatric Investigation Plan, 40 subjects were intra-operatively randomized 2:1 to Evicel® or additional sutures ('Sutures'). Data analysis was descriptive. The efficacy endpoint was treatment success rate, with success defined as intra-operative watertight closure after provocative Valsalva maneuver (primary endpoint). Safety endpoints were postoperative CSF leakage (incisional CSF leakage, pseudomeningocele or both) and surgical site complications (secondary endpoints).

RESULTS

Forty subjects (0.6-17 years) were randomized to Evicel® (N = 25) or Sutures (N = 15) (intention-to-treat). Intracranial tumor was the most common indication and procedures were mostly supratentorial craniotomies. Success rates were 92.0% for Evicel® and 33.3% for Sutures, with a 2.76 estimated ratio of success rates (Farrington-Manning 95% CI [1.53, 6.16]). Sensitivity analyses in per-protocol and safety sets showed similar results. Despite a higher rescue treatment rate, the frequencies of postoperative CSF leakage and wound complications were higher for Sutures than for Evicel®.

CONCLUSION

This small-scale prospective study shows Evicel® treatment to be safe and effective as an adjunct to primary sutured dura mater closure in a pediatric population. Compared to additional sutures, Evicel® was associated with reduced postoperative CSF leakage and surgical site complications. (Trial registration: The trial was registered as NCT02309645 and EudraCT 2013-003558-26).

Intravenous tranexamic acid for intracerebral meningioma resections: A randomized, parallel-group, non-inferiority trial

STUDY OBJECTIVES

Tranexamic acid (TXA) is an antifibrinolytic that is widely used to reduce surgical bleeding. However, TXA occasionally causes seizures and the risk might be especially great after neurosurgery. We therefore tested the hypothesis that TXA does not meaningfully increase the risk of postoperative seizures within 7 days after intracranial tumor resections.

DESIGN

Randomized, double-blind, placebo-controlled, non-inferiority trial.

SETTING

Beijing Tiantan Hospital, Capital Medical University.

PATIENTS

600 patients undergoing supratentorial meningioma resection were included from October 2020 to August 2022.

INTERVENTIONS

Patients were randomly assigned to a single dose of 20 mg/kg of TXA after induction (n = 300) or to the same volume of normal saline (n = 300).

MEASUREMENT

The primary outcome was postoperative seizures occurring within 7 days after surgery, analyzed in both the intention-to-treat and per-protocol populations. Non-inferiority was defined by an upper limit of the 95% confidence interval for the absolute difference being <5.5%. Secondary outcomes included incidence of non-epileptic complication within 7 days, changes in hemoglobin concentration, estimated intraoperative blood loss. Post hoc analyses included the types and timing of seizures, oozing assessment, and a sensitivity analysis for the primary outcome in patients with pathologic diagnosis of meningioma.

MAIN RESULTS

All 600 enrolled patients adhered to the protocol and completed the follow-up for the primary outcome. Postoperative seizures occurred in 11 of 300 (3.7%) of patients randomized to normal saline and 13 of 300 (4.3%) patients assigned to tranexamic acid (mean risk difference, 0.7%; 1-sided 97.5% CI, -∞ to 4.3%; P = 0.001 for noninferiority). No significant differences were observed in any secondary outcome. Post hoc analysis indicated similar amounts of oozing, calculated blood loss, recurrent seizures, and timing of seizures.

CONCLUSION

Among patients having supratentorial meningioma resection, a single intraoperative dose of TXA did not significantly reduce bleeding and was non-inferior with respect to postoperative seizures after surgery.

REGISTRY INFORMATION

This trial was registered at clinicaltrials.gov (NCT04595786) on October 22, 2020, by Dr.Yuming Peng.

The Role of Tranexamic Acid in Sleeve Gastrectomy: A Systematic Review and Meta-Analysis

Tranexamic acid (TXA) is an essential procoagulant drug used in various intra- and postoperative situations. Its efficacy and safety profile in obese cases undergoing laparoscopic sleeve gastrectomy (LSG) is still unresolved. Therefore, this meta-analysis evaluated and investigated the current intra- and postoperative effects and hazards of TXA on patients undergoing LSG. As for methodology, Web of Science, Cochrane Library, Scopus, and PubMed were thoroughly searched for relevant studies. Retrieved results were prepared for screening through Endnote, helping to identify eligible studies. Relevant patient characteristics and outcomes were extracted. The methodological quality of the relevant studies was appraised using the respected appraisal tool. Six studies of different designs were enrolled, comprising 753 cases that underwent LSG and administered TXA. Their mean BMI and age went from 37.3 to 56.25 kg/m2 and 33.5 to 43.25 years, respectively. Tranexamic acid significantly linked to reduction in intraoperative bleeding instances, operative blood loss, and operative duration, compared to placebo ((RR = 0.66, 95% CI [0.44, 0.98], P=0.04, I2 = 81%); (MD = -39.64, 95%CI [-75.49, -3.78], P=0.03, I2=94%); (MD=-5.84, 95%CI [-9.62, -2.05], P=0.003, I2=73%)). Tranexamic acid also significantly showed superiority regarding postoperative bleeding events and duration of hospitalization compared to the control group ((RR= 0.45, 95%CI [0.29, 0.69], P=0.0002, I2 =0%); (MD=-0.24, 95%CI [-0.32, -0.17], P< 0.0000, I2 =0%)). Moreover, follow-up of the enrolled patients for a minimum of three to six months resulted in no reported thromboembolic instances, suggesting a negligible risk for thromboembolism among patients undergoing LSG and receiving TXA. In conclusion, tranexamic acid demonstrates a robust safety and efficacy profile for its use in patients undergoing LSG, with no reported instances of thromboembolism. Variations in TXA administration regimens, bleeding definitions, procedural techniques, and potential confounding medications could not be accounted for, necessitating additional large-scale RCTs to address and bridge knowledge gaps.

Optimizing Blood Loss and Management in Craniosynostosis Surgery: A Systematic Review of Outcomes Over the Last 40 Years

Surgical correction of craniosynostosis can involve significant blood loss. Rates of allogenic blood transfusion have been reported to approach 100%. Multiple interventions have been described to reduce blood loss and transfusion requirements. The aim of this study was to analyze various approaches over the last 4 decades to optimize blood loss and management during craniosynostosis surgery.

PRISMA guidelines for systematic reviews were followed. PubMed and Cochrane database searches identified studies analyzing approaches to minimizing blood loss or transfusion rate in craniosynostosis surgery.

Primary outcomes included rate or amount of allogenic or autologous blood transfusion, estimated blood loss (EBL), postoperative hemoglobin (Hg), or hematocrit (Hct) levels. Secondary outcomes were examined when reported.

Fifty-two studies met inclusion criteria. There was marked heterogeneity regarding design, inclusion criteria, surgical intervention, and endpoints. The majority of the studies were nonrandomized and noncomparative. Four studies analyzed erythropoietin (EPO), 6 analyzed various cell-saver (CS) technologies, 18 analyzed antifibrinolytics (tranexamic acid [TXA], aminocaproic acid [ACA], and aprotinin [APO]), 8 analyzed various alternatives, and 16 analyzed multimodal pathways & protocols. Some studies analyzed multiple approaches.

Although the majority of studies reviewed represent level III/IV evidence, several high-quality level I studies were identified and included. Level I evidence supported an improvement in blood outcomes by utilizing EPO, CS, and TXA, individually or in concert with one another. Thus, this review suggests that a multi-prong approach may be the most effective means to optimize blood loss and transfusion outcomes in craniosynostosis surgery.

Topical and Intravenous Tranexamic Acid in Acyanotic Children Undergoing Congenital Heart Surgery: A Randomized Clinical Trial

INTRODUCTION

Postoperative bleeding is a common complication in congenital heart surgery. We aimed to evaluate effects of topical and intravenous tranexamic acid (TXA) administration on postoperative hemoglobin and bleeding in children with acyanotic congenital heart disease (CHD).

METHODS

In this randomized clinical trial, 50 acyanotic CHD children were allocated into two groups of topical (n = 25) and infusion (n = 25). Children in the infusion group were given intravenous TXA 50 mg/kg^-1 after sternotomy. Children in topical group were given 50 mg/kg^-1 TXA added to 20 mL of saline intrapericardially before sternal closure. Primary endpoint of study was comparison of postoperative hemoglobin and bleeding between topical and infusion groups. A linear mixed model (LMM) was used to estimate longitudinal changes in postoperative endpoints.

RESULTS

We did not observe significant differences in children's characteristics between two groups. Also, intraoperative and postoperative outcomes did not differ between two groups but children with intravenous TXA experienced significantly longer intubation time than topical children (P = 0.047). LMM analysis revealed that postoperative bleeding in topical group was lower compared to infusion group (P = 0.036). Also, age of children had a significant effect on mean changes of hemoglobin during postoperative care (β = -0.27, P = 0.030). No children died and none had serious postoperative complications such as seizures and reoperation.

CONCLUSIONS

We found that topical TXA is not superior to intravenous administration in management of blood loss. Also, no additional effect was found about topical TXA in further reducing transfusion rates and postoperative complications in acyanotic CHD children undergoing cardiac surgery.

Tranexamic acid-associated fatal status epilepticus in a pediatric non-cardiac surgery: A case report and literature review

Tranexamic acid (TXA) is widely utilized to control perioperative bleeding. TXA is considered a safe drug with few serious adverse effects, but many studies report TXA-associated seizures especially with cardiac surgeries. Usually, TXA-associated seizures persist for few minutes with no progression into status epilepticus. Here, we report, for the first time, a case of refractory status epilepticus after IV injection of TXA in a pediatric non-cardiac surgery. This case report and literature review aim to increase awareness about TXA-associated seizures and to provide mechanistic-based prevention and treatment recommendations. During adenotonsillectomy for a 4-year-old male child, TXA infusion started after induction of anesthesia for surgical bleeding prophylaxis. During recovery from anesthesia, the patient developed tonic-clonic convulsions which did not improve after two IV doses of midazolam but showed an improvement after a dose of propofol. The patients did not regain consciousness and was transferred to the ICU. He had recurrent treatment-resistant attacks of tonic-clonic convulsions. The patient developed acute kidney injury and died after 18 hours. In high-risk patients, using the lowest effective dose with early termination of TXA infusion and prolongation of administration of anesthetics may prevent seizures. General anesthetics (propofol and halogenated inhaled anesthetics) are considered the first line for prevention/treatment of TXA-associated seizures.

Safety and Efficacy of Local Tranexamic Acid for the Prevention of Surgical Bleeding in Soft-Tissue Surgery: A Review of the Literature and Recommendations for Plastic Surgery

Background:

Although high-bleed surgery routinely utilizes the antifibrinolytic drug tranexamic acid, most plastic surgical procedures are conducted in soft tissue with low-volume bleeding. Unease regarding possible systemic adverse effects prevents widespread systemic use, but local use of tranexamic acid is gaining popularity among plastic surgeons. Randomized controlled trials on topical use of tranexamic acid are mainly from high-bleed surgeries, and few studies address the effect in soft tissue. This article reviews the scientific evidence regarding local use of tranexamic acid in soft-tissue surgery, discusses pharmacological effects and possible adverse reactions, and presents recommendations for use in plastic surgery.

Methods:

A systematic search of databases for studies on local use of tranexamic acid in soft-tissue surgery was performed. Randomized controlled trials were included for a systematic review on effect; a narrative review regarding other clinically relevant aspects is based on extensive literature searches combined with the authors’ own research.

Results:

Fourteen randomized controlled trials, including 1923 patients, were included in the systematic review on local use of tranexamic acid in soft-tissue surgery.

Conclusions:

Local use of tranexamic acid may reduce blood loss comparably to intravenous prophylactic use with negligible risk of systemic adverse effects, but high-quality randomized controlled trials are few. Prolonged exposure to high local concentrations is discouraged, and direct contact with the central nervous system may cause seizures. No single superior means of administration or dosage is supported in the literature, and lowest effective dose is unknown. There may not be one single ideal dosing regimen, but rather many possibilities adaptable for different surgical situations.

Tranexamic Acid Administered During Off-Pump Coronary Artery Bypass Graft Surgeries Achieves Good Safety Effects and Hemostasis

Background

Tranexamic acid (TXA) administered during off-pump coronary artery bypass (OPCAB) surgeries has achieved good blood control in small cohorts. We aimed to investigate the safety issues and hemostasis associated with TXA administration during OPCAB in a large retrospective cohort study.

Methods

This study included 19,687 patients with OPCAB from 2009 to 2019. A total of 1,307 patients were excluded because they were younger than 18 years or certain values were missing. Among the remaining 18,380 patients, 10,969 were in the TXA group and 7,411 patients were in the no-TXA group. There were 4,889 patients whose TXA dose was ≥50 mg/kg, and the remaining 6,080 patients had a TXA dose of <50 mg/kg. Propensity score matching (PSM) was performed between the TXA and no-TXA groups and between the high-dose and low-dose groups, and statistical analysis was performed.

Results

Tranexamic acid administration did not increase the risk of hospital death or thromboembolic events. Patients who administered TXA had less blood loss at 24 h (478.32 ± 276.41 vs. 641.28 ± 295.09, p < 0.001) and 48 h (730.59 ± 358.55 vs. 915.24 ± 390.13, p < 0.001) and total blood loss (989.00 ± 680.43 vs. 1,220.01 ± 720.68, p < 0.001) after OPCAB than the patients with non-TXA. Therefore, the risk of total blood exposure [odds ratio (OR) = 0.50, 95% CI 0.47–0.54, p < 0.001] or blood component exposure (p < 0.001) was decreased significantly in the patients who administered TXA. The TXA dosage did not impact the patient survival, thromboembolic events, or blood management.

Conclusions

The application of TXA was safe and provided blood control in patients with OPCAB, and the dosage did not affect these parameters.

Safety of intravenous tranexamic acid in patients undergoing supratentorial meningiomas resection: protocol for a randomised, parallel-group, placebo control, non-inferiority trial

INTRODUCTION

Growing evidence recommends antifibrinolytic agent tranexamic acid (TXA) to reduce blood loss and transfusions rate in various surgical settings. However, postoperative seizure, as one of the major adverse effects of TXA infusion, has been a concern that restricts its utility in neurosurgery.

METHODS AND ANALYSIS

This is a randomised, placebo-controlled, non-inferiority trial. Patients with supratentorial meningiomas and deemed suitable for surgical resection will be recruited in the trial. Patients will be randomised to receive either a single administration of 20 mg/kg TXA or a placebo of the same volume with a 1:1 allocation ratio after anaesthesia induction. The primary endpoint is the cumulative incidence of early postoperative seizures within 7 days after craniotomy. Secondary outcomes include the incidence of non-seizure complications, changes of haemoglobin level from baseline, intraoperative blood loss, erythrocyte transfusion volume, Karnofsky Performance Status, all-cause mortality, and length of stay, and total hospitalisation cost.

ETHICS AND DISSEMINATION

This trial is registered at ClinicalTrial.gov and approved by the Chinese Ethics Committee of Registering Clinical Trials (ChiECRCT20200224). The findings will be disseminated in peer-reviewed journals and presented at national or international conferences relevant to subject fields.

TRIAL REGISTRATION NUMBER

NCT04595786.

Tranexamic Acid Administered During Off-Pump Coronary Artery Bypass Graft Surgeries Achieves Good Safety Effects and Hemostasis

BACKGROUND

Tranexamic acid (TXA) administered during off-pump coronary artery bypass (OPCAB) surgeries has achieved good blood control in small cohorts. We aimed to investigate the safety issues and hemostasis associated with TXA administration during OPCAB in a large retrospective cohort study.

METHODS

This study included 19,687 patients with OPCAB from 2009 to 2019. A total of 1,307 patients were excluded because they were younger than 18 years or certain values were missing. Among the remaining 18,380 patients, 10,969 were in the TXA group and 7,411 patients were in the no-TXA group. There were 4,889 patients whose TXA dose was ≥50 mg/kg, and the remaining 6,080 patients had a TXA dose of <50 mg/kg. Propensity score matching (PSM) was performed between the TXA and no-TXA groups and between the high-dose and low-dose groups, and statistical analysis was performed.

RESULTS

Tranexamic acid administration did not increase the risk of hospital death or thromboembolic events. Patients who administered TXA had less blood loss at 24 h (478.32 ± 276.41 vs. 641.28 ± 295.09, p < 0.001) and 48 h (730.59 ± 358.55 vs. 915.24 ± 390.13, p < 0.001) and total blood loss (989.00 ± 680.43 vs. 1,220.01 ± 720.68, p < 0.001) after OPCAB than the patients with non-TXA. Therefore, the risk of total blood exposure [odds ratio (OR) = 0.50, 95% CI 0.47-0.54, p < 0.001] or blood component exposure (p < 0.001) was decreased significantly in the patients who administered TXA. The TXA dosage did not impact the patient survival, thromboembolic events, or blood management.

CONCLUSIONS

The application of TXA was safe and provided blood control in patients with OPCAB, and the dosage did not affect these parameters.

Efficacy and safety of tranexamic acid in aneurysmal subarachnoid hemorrhage: A meta-analysis of randomized controlled trials

INTRODUCTION

Tranexamic acid, as a traditional hemostatic agent, is commonly used to treat or prevent excessive blood loss. However, the role of tranexamic acid in promoting good clinical outcomes and reducing mortality and risk of adverse events during the treatment of aneurysmal subarachnoid hemorrhage remains unclear.

METHODS

In strict accordance with the inclusion and exclusion criteria, Cochrane Library, Embase, Web of Science, and PubMed databases were assessed for randomized controlled trials (published between 1980 and 2021). Data were analyzed using STATA 16.0 and RevMan 5.3. In addition, the fixed-effects model (M-H method) and effect size (risk difference; RD) were used as a pooled measure to combine data. We also performed a post hoc sensitivity analysis and subgroup analysis to evaluate each outcome with low heterogeneity.

RESULTS

A meta-analysis revealed that although tranexamic acid was related to less rebleeding (RD = -0.06; 95% CI [-0.09, -0.03]; P = 0.0006), there is evidence that it has no an effect on good clinical outcomes or mortality (RD = -0.01; 95% CI [-0.05, 0.02]; P = 0.51; RD = 0.00; 95% CI [-0.03, 0.04]; P = 0.91). Tranexamic acid was associated with increased hydrocephalus (RD = 0.04; 95% CI [0.01, 0.08]; P = 0.02) and seizure (RD = 0.04; 95% CI [0.00, 0.08]; P = 0.05). The incidence of thromboembolic complications or delayed cerebral ischemia was not different in the two groups (RD = -0.01; 95% CI [-0.04, 0.03]; P = 0.62; RD = 0.00; 95% CI [-0.03, 0.03]; P = 0.96), and significant drug-related overall adverse events were identified (RD = 0.02; 95% CI [0.00, 0.04]; P = 0.03).

CONCLUSIONS

These findings indicate that the routine use of tranexamic acid is not suggested for patients with aneurysmal subarachnoid hemorrhage.

Tranexamic acid after cardiopulmonary bypass does not increase risk of postoperative seizures: a retrospective study

OBJECTIVE

To evaluate the effects of administering tranexamic acid (TXA) after cardiopulmonary bypass, instead of after anesthesia induction, on postoperative seizures and blood transfusion requirements.

METHODS

Adult patients who underwent valve surgery and/or coronary artery bypass grafting at West China Hospital between July 1, 2011 and December 31, 2016 were retrospectively analyzed. Patients either received TXA after bypass (n = 2062) or not (n = 4236). Logistic regression and propensity score matching analysis were performed to assess effects of TXA on postoperative seizures and blood product requirements in hospital.

RESULTS

Among 6298 patients, seizures occurred in 2.4% (102/4236) in the no-TXA group and 2.7% (56/2062) in the TXA group (P = 0.46). The number of patients receiving any blood products was greater in the no-TXA group (57.3%, 2428/4236) than in the TXA group (53.1%, 1095/2062) (P < 0.01), and the volume of blood products was also greater in the no-TXA group (1.5 vs. 1.0 units, P < 0.01). TXA was not associated with increased incidence of postoperative seizures (adjusted OR 1.16, 95% CI 0.83-1.62) but was associated with lower incidence of a requirement for blood products (adjusted OR 0.82, 95% CI 0.73-0.92). Similar results were obtained after patients from the two groups were matched based on propensity scoring. TXA was associated with reduced requirements for fresh frozen plasma, platelets and cryoprecipitate, but not red blood cells.

CONCLUSIONS

Administering TXA after bypass may reduce requirements for blood products without increasing risk of seizures following cardiac surgery.

Ventriculolumbar perfusion and inhalational anesthesia with sevoflurane in an accidental intrathecal injection of tranexamic acid: unreported treatment options

BACKGROUND

Tranexamic acid (TXA) decreases hemorrhage-related mortality in trauma patients and is increasingly being used during obstetric and orthopedic surgeries. Inadvertent intrathecal injection of TXA is a rare, potentially lethal event leading to dose-dependent cardiotoxicity and neurotoxicity. TXA enhances neuronal excitation by antagonizing inhibitory γ-aminobutyric acid type A and glycine receptors. Until now, mechanistic-based pharmacological treatments targeting multiple central nervous system receptors have been advocated for use in such cases, with no data on intrathecal TXA elimination techniques.

CASE PRESENTATION

A patient scheduled for hip surgery accidentally received 350 mg of intrathecal TXA instead of levobupivacaine. The clinical picture progressed from spinal segmental myoclonus to generalized convulsions and malignant arrhythmias. The treatment consisted of ventriculolumbar perfusion with normal saline at a rate of 50 mL/hour starting 5 hours after TXA administration and inhalational sedation with sevoflurane, in addition to drugs acting on multiple receptors at different central nervous system levels. Over 2 months the neurological status improved, although it was not complete.

CONCLUSIONS

For the first time, the feasibility and possible clinical efficacy of combined treatment with ventriculolumbar perfusion and inhalational sedation with sevoflurane were demonstrated. A referral to a neurosurgical facility is recommended in patients with acute TXA-induced neurotoxicity and cardiotoxicity.

Tranexamic acid to reduce operative blood loss in brain tumor surgery: A meta-analysis

Background:

Major blood loss during neurosurgery may result in a variety of complications, such as potentially fatal hemodynamic instability. Brain tumor and skull base surgery is among the high bleeding risk procedures. Tranexamic acid (TXA) has been found to reduce bleeding events in various fields of medicine.

Methods:

We searched for all randomized controlled trials published in English or Bahasa which compared the use of TXA with placebo in brain tumor surgery. The studies should include adult patients with intracranial tumor who received TXA before skin incision. The primary and secondary outcomes are intraoperative blood loss and the need of transfusion.

Results:

This meta-analysis included a total of 200 patients from three studies. TXA resulted in less blood loss with pooled mean difference of −292.80 (95% CI, −431.63, −153.96, P<0.05). The need of transfusion was not significant between TXA and control group (pooled mean difference −85.36, 95% CI, −213.23 – (42.51), P=0.19).

Conclusion:

TXA reduced the volume of blood loss but did not reduce the need of blood transfusion.

Intraoperative tranexamic acid use in patients undergoing excision of intracranial meningioma: Randomized, placebo-controlled trial

Background:

Intracranial meningioma resection is associated with substantial intraoperative bleeding. Intraoperative tranexamic acid (TXA) use can reduce bleeding in a variety of surgical procedures. The objective of this study was to evaluate the effects of TXA treatment on blood loss and transfusion requirements in patient undergoing resection of intracranial meningioma.

Methods:

We conducted a prospective, randomized double-blind clinical study. The patient scheduled to undergo excision of intracranial meningioma were randomly assigned to receive intraoperatively either intravenous TXA or placebo. Patients in the TXA group received intravenous bolus of 20 mg/kg over 20 min followed by an infusion of 1 mg/kg/h up to surgical wound closure. Efficacy was evaluated based on total blood loss and transfusion requirements. Postoperatively, thrombotic complications, convulsive seizure, and hematoma formation were noted.

Results:

Ninety-one patients were enrolled and randomized: 45 received TXA (TXA group) and 46 received placebo (group placebo). Total blood loss was significantly decreased in TXA group compared to placebo (283 ml vs. 576 ml; P < 0.001). Transfusion requirements were comparable in the two groups (P = 0.95). The incidence of thrombotic complications, convulsive seizure, and hematoma formation was similar in the two groups.

Conclusion:

TXA significantly reduces intraoperative blood loss, but did not significantly reduced transfusion requirements in adults undergoing resection of intracranial meningioma.

Tranexamic acid: current use in obstetrics, major orthopedic, and trauma surgery

PURPOSE

In this Continuing Professional Development module, we review the practical pharmacology of tranexamic acid and its clinical use in trauma, obstetrics, and major orthopedic surgery.

PRINCIPAL FINDINGS

Tranexamic acid is a synthetic drug that inhibits fibrinolysis. Multiple clinical trials in various clinical settings have shown that it can reduce blood loss, transfusion rates, and bleeding-associated mortality. In trauma and obstetrical bleeding, early tranexamic acid administration (< three hours) may have greater clinical benefits. Overall, tranexamic acid use appears safe with no significant increase of thromboembolic or seizure events. Nevertheless, current evidence has limitations related to wide heterogeneity in dose, route, and timing of drug administration, as well as generalizability of the large-scale trial findings to higher income nations.

CONCLUSIONS

Tranexamic acid is an efficacious and safe pharmacological-based blood conservation technique in the management of clinically significant hemorrhage. All anesthesiologists should have a good understanding of the pharmacotherapeutic properties and perioperative role of tranexamic acid therapy both inside and outside of the operating room. The use of tranexamic acid is likely to continue to rise with endorsement by various clinical guidelines and healthcare organizations. Further quantitative research is needed to evaluate optimal dosing and drug efficacy in these clinical scenarios.

High-dose Continuous Infusion of Tranexamic Acid for Controlling Life-threatening Bleed in Advanced Cancer Patients

Life-threatening bleeding although uncommon in palliative care is associated with significant distress among patients and family. The current guidelines emphasize the need for identification of a patient with early signs of bleeding and providing assurance and comfort care to patients and family in case of an event. There is very little known about the role of high dose of tranexamic acid, a lysine analog in controlling the bleeding irrespective of the underlying pathophysiology of the bleed. Tranexamic acid is known to competitively block the lysine-binding site of plasminogen and thus inhibit the activation of plasminogen to plasmin and at high-concentration tranexamic acid noncompetitively blocks plasmin, thus inhibiting the dissolution and degradation of fibrin clots by plasmin. Here, we discuss two case studies of patients who presented with massive bleed from the tumor site. With a high dose of continuous intravenous infusion of tranexamic acid, there was a complete arrest of the bleed with a reduction in the requirement for blood transfusion.

Fibrinolysis and bleeding of unknown cause

Patients with bleeding of unknown cause (BUC) present with a variety of mild to moderate bleeding symptoms, but no hemostatic abnormalities can be found. Hyperfibrinolysis is rarely evaluated as the underlying cause for bleeding in clinical practice, and well-established global assays for abnormal fibrinolysis are lacking. Few patients with definitive fibrinolytic disorders, including α2-antiplasmin deficiency, plasminogen activator inhibitor 1 deficiency, or Quebec platelet disorder, have been reported. This review aims to summarize data on established fibrinolytic disorders and to discuss assessments of fibrinolysis in prior bleeding cohorts. Furthermore, we review available global tests with the potential to measure fibrinolysis, such as turbidity fibrin clot assays and rotational thromboelastometry, and their relevance in the workup of patients with BUC. We conclude that, due to the lack of adequate global tests, hyperfibrinolysis might be an underdiagnosed cause for a bleeding disorder. The diagnosis of hyperfibrinolytic bleeding disorders would improve patient care as effective treatment with antifibrinolytic agents is available.

Incorrect Route for Injection: Inadvertent Tranexamic Acid Intrathecal Injection

Tranexamic acid has been increasingly used due to its safety and effectiveness. It has been associated with multiple reported cases of errors due to lack of attention, incorrect labeling of the syringes, or look-alike with other medications leading to the incorrect route of injection and the associated catastrophic sequela. Here we report a case of wrong route injection of tranexamic acid during spinal anesthesia, leading to myoclonic seizures and eventually intensive care unit admission of a patient undergoing orthopedic surgery. It is reported that higher doses of tranexamic acid would cause massive sympathetic discharge as evidenced by the initial hypertensive response reported in our case report and also in some repeated patient. Tranexamic acid induced seizures either from direct cerebral ischemia secondary to decreases in regional or global or from neuronal hyperexcitability by blockage of inhibitory cortical-gamma aminobutyric acid (GABA)-A receptors. Some evidence has been shown for dose-related neurotoxicity in the animal model, with greater severity and duration of seizure with increasing doses.

Analysis of serum tranexamic acid in patients undergoing open heart surgery

BACKGROUND

Tranexamic acid is a drug used during open cardiac surgery to prevent blood loss. The blood levels of 10-100 µg/mL are reported to be in the therapeutic range and higher levels are linked to increased incidence of adverse effects. The aim of this study was to optimize and validate an LC-MS/MS method for serum tranexamic acid and measure its levels in patients from the DEPOSITION Pilot trial in order to prove the concept that topical administration will yield lower serum concentration.

METHODS

The method development was carried out in several steps including sample preparation, and optimization of chromatography and tandem mass spectrometry parameters. Method validation including day-to-day precision with 4 QC levels, limit of detection, sample stability, carryover, and concentration-signal linearity was carried out. Ninety patient samples were analyzed using the validated method.

RESULTS

Fast and efficient LC-MS/MS method for analysis of tranexamic acid in serum was developed. The run time was 7 min with the total time of one hour including the sample preparation. The method precision was acceptable (%CV = 10.5-12.6%) with no sample carryover observed. The matrix effect on the analytical sensitivity was negligible and the lower limit of detection was 0.5 µg/mL. The difference in the mean adjusted concentrations between topical (45 patients) and intravenous (45 patients) groups was statistically significant (0.1154 µg/mL/kg vs. 0.2542 µg/mL/kg, p < 0.0001) CONCLUSIONS: Rapid and simple LC-MS/MS method for analysis of tranexamic acid was optimized and validated. The laboratory has played a crucial role in proving the concept that topical administration yields significantly lower systemic levels of tranexamic acid, and thus decreases the risk of adverse outcomes in patients undergoing open cardiac surgery.

Topical versus low-dose systemic tranexamic acid in pediatric cardiac surgery: A randomized clinical study

OBJECTIVES

The current study aimed to compare the benefits of topical and low-dose systemic tranexamic acid administration in pediatric cardiac surgery.

METHODS

A total of 117 children undergoing cardiac surgery for congenital heart disease were assigned into three groups. Patients in the systemic group received 20 mg/kg^-1 tranexamic acid through the cardiopulmonary bypass followed by another dose of 20 mg/kg^-1 after cardiopulmonary bypass separation. Patients in the topical group were administered with 50 mg/kg^-1 tranexamic acid poured into the pericardium, while the control group received no antifibrinolytics. The outcome measures of bleeding and blood products transfusion were recorded over the first 48 h postoperatively.

RESULTS

Chest tube drainage was significantly lower in both topical and systemic groups than the control group, but it did not differ between the case groups. Blood products requirement did not show a difference between groups. Neurological or thromboembolic events did not variate among the groups, and no deaths occurred in this study.

CONCLUSION

Topical or systemic tranexamic acid administration reduced postoperative blood loss effectively without adding an extra risk.

Effects of tranexamic acid on the activity of glutamate transporter EAAT3

Background

Tranexamic acid (TXA) is the most widely used hemostatic agent in surgical patients. However, when used in a high dose, it could cause a seizure in the postoperative period. The exact effector mechanism behind the seizure triggering remains unknown. Therefore, the authors investigated the effects of TXA on the activity of glutamate transporter type 3 (excitatory amino acid transporter 3; EAAT3), which is the main neuronal glutamate transporter type.

Methods

EAAT3 was expressed in Xenopus laevis oocytes through mRNA injection. Oocytes were incubated with diluted tranexamic acid for 72 h. Two-electrode voltage clamping was used to measure membrane currents before, during, and after applying 30 µM L-glutamate. Responses were quantified by integrating the current traces and reported in microcoulombs (µC). Results were presented as mean ± SEM.

Results

TXA (30 to 1,000 µM) significantly decreased EAAT3 activity. Our kinetic study showed that V_max was significantly decreased in the TXA group compared with the control group (1.1 ± 0.1 vs. 1.4 ± 0.1 µC, n = 18–23, P = 0.043), but the K_m did not significantly change (12.7 ± 3.9 µM for TXA vs. 12.8 ± 3.8 for control, n = 18–23, P = 0.986).

Conclusions

Our results suggest that TXA attenuates EAAT3 activity, which may explain its proconvulsant effect.

Cerebrovascular Complications of Pediatric Blunt Trauma

Ischemic and hemorrhagic stroke can occur in the setting of pediatric trauma, particularly those with head or neck injuries. The risk of stroke appears highest within the first two weeks after trauma. Stroke diagnosis may be challenging due to lack of awareness or concurrent injuries limiting detailed neurological assessment. Other injuries may also complicate stroke management, with competing priorities for blood pressure, ventilator management, or antithrombotic timing. Here we review epidemiology, clinical presentation, and diagnostic approach to blunt arterial injuries including dissection, cerebral sinovenous thrombosis, mineralizing angiopathy, stroke from abusive head trauma, and traumatic hemorrhagic stroke. Owing to the complexities and heterogeneity of concomitant injuries in stroke related to trauma, a single pathway for stroke management is impractical. Therefore providers must understand the goals and possible costs or consequences of stroke management decisions to individualize patient care. We discuss the physiological principles of cerebral perfusion and oxygen delivery, considerations for ventilator strategy when stroke and lung injury are present, and current available evidence of the risks and benefits of anticoagulation to provide a framework for multidisciplinary discussions of cerebrovascular injury management in pediatric patients with trauma.

Inhaled Tranexamic Acid As a Novel Treatment for Pulmonary Hemorrhage in Critically Ill Pediatric Patients: An Observational Study

Objectives:

To describe the use of inhaled or endotracheally instilled tranexamic acid in critically ill pediatric patients for the treatment of pulmonary hemorrhage, which can be severe, life-threatening, and include potentially high-risk management procedures.

Design:

Retrospective observational study from 2011-2018 with patients followed until hospital discharge.

Setting:

Free-standing children’s hospital with an annual ICU volume of more than 3,500 yearly admissions.

Patients:

Pediatric patients, ages 0 to 18 years, admitted to an ICU and who received at least one dose of inhaled or endotracheally instilled tranexamic acid were included.

Interventions:

Inhaled or endotracheally instilled tranexamic acid.

Measurements and Main Results:

This study described the efficacy and adverse effects of patients who received inhaled or endotracheally instilled tranexamic acid. A total of 19 patients met inclusion criteria; median age was 72 months (11–187 mo), most patients were female (11, 58%), and almost half our patients (8, 42%) had congenital heart disease. Nine of 19 encounters (47%) had diffuse alveolar hemorrhage, four (21%) had pulmonary hemorrhage related to major aortopulmonary collateral arteries, two (11%) had mucosal airway bleeding, two (11%) were iatrogenic, one had a pulmonary embolism, and one patient did not have their etiology of pulmonary hemorrhage determined. Cessation of pulmonary hemorrhage was achieved in 18 of 19 patients (95%) with inhaled tranexamic acid with no major adverse events recorded.

Conclusions and Relevance:

We demonstrate that inhaled tranexamic acid may be safely used to treat pulmonary hemorrhage from varied etiologies in critically ill pediatric patients. Prospective studies are required in this vulnerable population to determine optimal dosing and delivery strategies, as well as to define any differential effect according to etiology.

Incidence and predictors of early seizures in intracerebral haemorrhage and the effect of tranexamic acid

Introduction

Seizures are common after intracerebral haemorrhage. Tranexamic acid increases the risk of seizures in non-intracerebral haemorrhage population but its effect on post-intracerebral haemorrhage seizures is unknown. We explored the risk factors and outcomes of seizures after intracerebral haemorrhage and if tranexamic acid increased the risk of seizures in the Tranexamic acid for IntraCerebral Haemorrhage-2 trial.

Patients and methods

Seizures were reported prospectively up to day 90. Cox regression analyses were used to determine the predictors of seizures within 90 days and early seizures (≤7 days). We explored the effect of early seizures on day 90 outcomes.

Results

Of 2325 patients recruited, 193 (8.3%) had seizures including 163 (84.5%) early seizures and 30 (15.5%) late seizures (>7 days). Younger age (adjusted hazard ratio (aHR) 0.98 per year increase, 95% confidence interval (CI) 0.97-0.99; p = 0.008), lobar haematoma (aHR 5.84, 95%CI 3.58-9.52; p < 0.001), higher National Institute of Health Stroke Scale (aHR 1.03, 95%CI 1.01-1.06; p = 0.014) and previous stroke (aHR 1.66, 95%CI 1.11-2.47; p = 0.013) were associated with early seizures. Tranexamic acid did not increase the risk of seizure within 90 days. Early seizures were associated with worse modified Rankin Scale (adjusted odds ratio (aOR) 1.79, 95%CI 1.12-2.86, p = 0.015) and increased risk of death (aOR 3.26, 95%CI 1.98-5.39; p < 0.001) at day 90.Discussion and conclusion: Lobar haematoma was the strongest independent predictor of early seizures after intracerebral haemorrhage. Tranexamic acid did not increase the risk of post-intracerebral haemorrhage seizures in the first 90 days. Early seizures resulted in worse functional outcome and increased risk of death.

Topical moistening of mastectomy wounds with diluted tranexamic acid to reduce bleeding: randomized clinical trial

BACKGROUND

Topical administration of tranexamic acid (TXA) may be an alternative to intravenous administration to reduce bleeding with a lower risk of systemic adverse events. The aim of this study was to investigate whether moistening a surgical wound with TXA before closure, leaving a thin film of drug only, would reduce postoperative bleeding.

METHODS

This was a two-centre, stratified, parallel-group, placebo-controlled, double-blind RCT. Patients undergoing mastectomy with or without axillary lymph node clearance were randomized 1 : 1 to moistening of wound surface before closure with either 25 mg/ml TXA or 0·9 per cent sodium chloride (placebo). The primary endpoint was postoperative bleeding as measured by drain production in the first 24 h. Secondary endpoints were early haematoma, total drain production, postoperative complications and late aspirations of seroma within 3 months.

RESULTS

Between 1 January 2016 and 31 August 2018, 208 patients were randomized. Two patients were converted to a different surgical procedure at surgery, and four did not receive the intervention owing to technical error. Thus, 202 patients were included in the study (101 in the TXA and 101 in the placebo group). TXA reduced mean drain production at 24 h (110 versus 144 ml; mean difference 34 (95 per cent c.i. 8 to 60) ml, P = 0·011). One patient in the TXA group had early haematoma compared with seven in the placebo group (odds ratio (OR) 0·13 (95 per cent c.i. 0·02 to 1·07); P = 0·057). There was no significant difference in postoperative complications between TXA and placebo (13 versus 10; OR 1·11 (0·45 to 2·73), P = 0·824) or need for late seroma aspirations (79 versus 67 per cent; OR 1·83 (0·91 to 3·68), P = 0·089).

CONCLUSION

Moistening the wound with TXA 25 mg/ml before closure reduces postoperative bleeding within the first 24 h in patients undergoing mastectomy. Registration number: NCT02627560 (https://clinicaltrials.gov).

Fibrinolysis Inhibitors: Potential Drugs for the Treatment and Prevention of Bleeding

Hyperfibrinolytic situations can lead to life-threatening bleeding, especially during cardiac surgery. The approved antifibrinolytic agents such as tranexamic acid, ε-aminocaproic acid, 4-aminomethylbenzoic acid, and aprotinin were developed in the 1960s without the structural insight of their respective targets. Crystal structures of the main antifibrinolytic targets, the lysine binding sites on plasminogen's kringle domains, and plasmin's serine protease domain greatly contributed to the structure-based drug design of novel inhibitor classes. Two series of ligands targeting the lysine binding sites have been recently described, which are more potent than the most-widely used antifibrinolytic agent, tranexamic acid. Furthermore, four types of promising active site inhibitors of plasmin have been developed: tranexamic acid conjugates targeting the S1 pocket and primed sites, substrate-analogue linear homopiperidylalanine-containing 4-amidinobenzylamide derivatives, macrocyclic inhibitors addressing nonprimed binding regions, and bicyclic 14-mer SFTI-1 analogues blocking both, primed and nonprimed binding sites of plasmin. Furthermore, several allosteric plasmin inhibitors based on heparin mimetics have been developed.

Serum Concentrations and Pharmacokinetics of Tranexamic Acid after Two Means of Topical Administration in Massive Weight Loss Skin-Reducing Surgery

Supplemental Digital Content is available in the text.

Background:

Topical administration of tranexamic acid to reduce bleeding is receiving increasing attention, as it is inexpensive, simple, and possibly beneficial in most surgery. Concerns regarding potential systemic adverse effects such as thromboembolic events and seizures may prevent general use of tranexamic acid. Although serum concentrations after topical application are assumed to be low, proper pharmacokinetic studies of tranexamic acid after topical application are lacking.

Methods:

The authors have investigated systemic absorption of tranexamic acid after two means of topical administration in patients undergoing abdominoplasty after massive weight loss: a bolus of 200 ml of 5 mg/ml into the wound cavity versus moistening the wound surface with 20 ml of 25 mg/ml. Twelve patients were recruited in each group. Serum concentrations achieved were compared with those after administration of 1 g as an intravenous bolus to arthroplasty patients. Serial blood samples for tranexamic acid analysis were obtained for up to 24 hours.

Results:

After intravenous administration, the peak serum concentration was 66.1 ± 13.0 µg/ml after 6 ± 2 minutes. Peak serum concentration after topical moistening was 5.2 ± 2.6 µg/ml after 80 ± 33 minutes, and in the topical bolus group, it was 4.9 ± 1.8 µg/ml after 359 ± 70 minutes. Topical moistening resulted in homogenous and predictable absorption across the individuals included, whereas topical bolus administration caused variable and unpredictable serum concentrations.

Conclusion:

Topical administration of tranexamic acid in patients undergoing abdominoplasty results in low serum concentrations, which are highly unlikely to cause systemic effects.

Termination of bleeding by a specific, anticatalytic antibody against plasmin

BACKGROUND

Excessive, plasmin-mediated fibrinolysis augments bleeding and contributes to death in some patients. Current therapies for fibrinolytic bleeding are limited by modest efficacy, low potency, and off-target effects.

OBJECTIVES

To determine whether an antibody directed against unique loop structures of the plasmin protease domain may have enhanced specificity and potency for blocking plasmin activity, fibrinolysis, and experimental hemorrhage.

METHODS

The binding specificity, affinity, protease cross-reactivity and antifibrinolytic properties of a monoclonal plasmin inhibitor antibody (Pi) were examined and compared with those of epsilon aminocaproic acid (EACA), which is a clinically used fibrinolysis inhibitor.

RESULTS

Pi specifically recognized loop 5 of the protease domain, and did not bind to other serine proteases or nine other non-primate plasminogens. Pi was ~7 logs more potent in neutralizing plasmin cleavage of small-molecule substrates and >3 logs more potent in quenching fibrinolysis than EACA. Pi was similarly effective in blocking catalysis of a small-molecule substrate as α2 -antiplasmin, which is the most potent covalent inhibitor of plasmin, and was a more potent fibrinolysis inhibitor. Fab or chimerized Fab fragments of Pi were equivalently effective. In vivo, in a humanized model of fibrinolytic surgical bleeding, Pi significantly reduced bleeding to a greater extent than a clinical dose of EACA.

CONCLUSIONS

A mAb directed against unique loop sequences in the protease domain is a highly specific, potent, competitive plasmin inhibitor that significantly reduces experimental surgical bleeding in vivo.

The safety and efficiency of intravenous administration of tranexamic acid in coronary artery bypass grafting (CABG): a meta-analysis of 28 randomized controlled trials

Background

The safety and efficiency of intravenous administration of tranexamic acid (TXA) in coronary artery bypass grafting (CABG) remains unconfirmed. Therefore, we conducted a meta-analysis on this topic.

Methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PUBMED and EMBASE for randomized controlled trials on the topic. The results of this work are synthetized and reported in accordance with the PRISMA statement.

Results

Twenty-eight studies met our inclusion criteria. TXA reduced the incidence of postoperative reoperation of bleeding (relative risk [RR], 0.46; 95% confidence interval [CI]; 0.31–0.68), the frequency of any allogeneic transfusion (RR, 0.64; 95% CI, 0.52–0.78) and the postoperative chest tube drainage in the first 24 h by 206 ml (95% CI − 248.23 to − 164.15). TXA did not significantly affect the incidence of postoperative cerebrovascular accident (RR, 0.93; 95%CI, 0.62–1.39), mortality (RR, 0.82; 95%CI, 0.53–1.28), myocardial infarction (RR, 0.90; 95%CI, 0.78–1.05), acute renal insufficiency (RR, 1.01; 95%CI, 0.77–1.32). However, it may increase the incidence of postoperative seizures (RR, 6.67; 95%CI, 1.77–25.20). Moreover, the subgroup analyses in on-pump and off-pump CABG, the sensitivity analyses in trials randomized more than 99 participants and sensitivity analyses that excluded the study with the largest number of participants further strengthened the above results.

Conclusions

TXA is effective to reduce reoperation for bleeding, blood loss and the need for allogeneic blood products in patients undergoing CABG without increasing prothrombotic complication. However, it may increase the risk of postoperative seizures.

Electronic supplementary material

The online version of this article (10.1186/s12871-019-0761-3) contains supplementary material, which is available to authorized users.

Decreasing Postoperative Blood Loss by Topical vs. Intravenous Tranexamic Acid in Open Cardiac Surgery (DEPOSITION) study: Results of a pilot study

BACKGROUND

Cardiac surgery patients are at high risk for postoperative bleeding. Intravenous (IV) tranexamic acid (TxA) is a commonly used antifibrinolytic drug, but is associated with postoperative seizures. We conducted this pilot randomized controlled trial (RCT) to determine the feasibility of a larger trial that will be designed to investigate the impact of TxA administration route, intrapericardial (IP) vs IV, on postoperative bleeding and seizures.

METHODS

In this single-center, double-blinded, pilot RCT we enrolled adult patients undergoing nonemergent on-pump cardiac operations through a median sternotomy. Participants were randomized to IP or IV TxA groups. The primary outcomes were cumulative chest tube drainage, transfusion requirements, and incidence of postoperative seizures.

RESULTS

A total of 97 participants were randomized to the intervention and control groups. Baseline characteristics were similar in both groups. Most participants underwent a CABG and/or aortic valve replacement. There was no statistical difference. The IP TxA group was found to have a tendency for less chest tube drainage in comparison to the IV TxA group, 500.5 (370.0-700.0) and 540.0 (420.0-700.0) mL, respectively, which was not statistically significant (P = 0.2854). Fewer participants in the IP TxA group with cardiac tamponade and/or required a reoperation for bleeding and fewer packed red blood cell transfusions. None of the IP TxA group developed seizure vs one from the IV TxA group.

CONCLUSION

This is the first known pilot RCT to investigate the role of TxA route of administration in open cardiac surgery. Intrapericardial TxA shows promising results with decreased bleeding, transfusion requirements, reoperations, and postoperative seizures. A larger RCT is needed to confirm these results and lead to a change in practice.

The Role of Antifibrinolytics in Reducing Blood Loss During Craniofacial or Orthognathic Surgical Procedures: A Meta-Analysis

PURPOSE

Use of antifibrinolytic drugs in craniofacial and orthognathic surgery seems quite promising and has strong advocates. However, supporting evidence is controversial and limited by a small sample of individual studies. We sought to systematically review and meta-analyze the available data regarding the role of preoperative or intraoperative antifibrinolytic drugs (eg, tranexamic acid, aprotinin, or aminocaproic acid) in craniofacial and orthognathic surgery.

MATERIALS AND METHODS

We searched PubMed, Scopus, Embase, the Cochrane Library, and Web of Science through April 19, 2018, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Outcomes of interest included the volume of blood loss, volume of transfusions, and operative time. A meta-analysis was performed with a random-effects model using Review Manager (RevMan) software (The Cochrane Collaboration, Copenhagen, Denmark).

RESULTS

We identified 32 eligible studies with 749 patients undergoing craniofacial surgery and 546 undergoing orthognathic surgery. Meta-analysis showed that antifibrinolytic use led to statistically significant decreases in blood loss and blood transfusions for craniofacial procedures in adult or pediatric patients and to significantly less blood loss during orthognathic surgical procedures. Operative time did not significantly differ for either type of surgery.

CONCLUSIONS

Antifibrinolytics can significantly reduce blood loss in craniofacial surgical procedures including pediatric craniosynostosis and adult rhinoplasties and in orthognathic surgical procedures, as well as transfusion requirements in pediatric craniofacial surgical procedures. However, the clinical significance of the medications is still questionable because of the relative paucity of information on adverse effects and the usual small volume loss during those operations.

Plasminogen binding inhibitors demonstrate unwanted activities on GABAA and glycine receptors in human iPSC derived neurons

Plasminogen binding inhibitors (PBIs) reduce the risk of bleeding in hemorrhagic conditions. However, generic PBIs are also associated with an increased risk of seizures, an adverse effect linked to unwanted activities towards inhibitory neuronal receptors. Development of novel PBIs serve to remove compounds with such properties, but progress is limited by a lack of higher throughput methods with human translatability. Herein we apply human induced pluripotent stem cell (hiPSC) derived neurons in combination with dynamic mass redistribution (DMR) technology to demonstrate robust and reproducible modulation of both GABA_A and glycine receptors. These cells respond to GABA (EC₅₀ 0.33 ± 0.18 μM), glycine (EC₅₀ 11.0 ± 3.7 μM) and additional ligands in line with previous reports from patch clamp technologies. Additionally, we identify and characterize a competitive antagonistic behavior of the prototype inhibitor and drug tranexamic acid (TXA). Finally, we demonstrate proof of concept for effective counter-screening of lead series compounds towards unwanted GABA_A receptor activities. No activity was observed for a previously identified PBI candidate drug, AZD6564, whereas a discontinued analog, AZ13267257, could be characterized as a potent GABA_A receptor agonist.

High Concentrations of Tranexamic Acid Inhibit Ionotropic Glutamate Receptors

BACKGROUND

The antifibrinolytic drug tranexamic acid is structurally similar to the amino acid glycine and may cause seizures and myoclonus by acting as a competitive antagonist of glycine receptors. Glycine is an obligatory co-agonist of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors. Thus, it is plausible that tranexamic acid inhibits NMDA receptors by acting as a competitive antagonist at the glycine binding site. The aim of this study was to determine whether tranexamic acid inhibits NMDA receptors, as well as α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and kainate subtypes of ionotropic glutamate receptors.

METHODS

Tranexamic acid modulation of NMDA, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, and kainate receptors was studied using whole cell voltage-clamp recordings of current from cultured mouse hippocampal neurons.

RESULTS

Tranexamic acid rapidly and reversibly inhibited NMDA receptors (half maximal inhibitory concentration = 241 ± 45 mM, mean ± SD; 95% CI, 200 to 281; n = 5) and shifted the glycine concentration-response curve for NMDA-evoked current to the right. Tranexamic acid also inhibited α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (half maximal inhibitory concentration = 231 ± 91 mM; 95% CI, 148 to 314; n = 5 to 6) and kainate receptors (half maximal inhibitory concentration = 90 ± 24 mM; 95% CI, 68 to 112; n = 5).

CONCLUSIONS

Tranexamic acid inhibits NMDA receptors likely by reducing the binding of the co-agonist glycine and also inhibits α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and kainate receptors. Receptor blockade occurs at high millimolar concentrations of tranexamic acid, similar to the concentrations that occur after topical application to peripheral tissues. Glutamate receptors in tissues including bone, heart, and nerves play various physiologic roles, and tranexamic acid inhibition of these receptors may contribute to adverse drug effects.

Pharmacological management of perioperative bleeding in cardiac surgery

[first paragraph of article]In spite of the growing discoveries in cardiac surgery, perioperative bleeding remains one of the most common causes of morbidity and mortality. Around 50-60% of cardiac surgery patients receive blood transfusions, which are harmful and strongly associated with increased morbidity, mortality, hospital stay, and hospital cost. Patients taken back to the OR for re-exploration and control of bleeding after cardiac surgery, have a four-fold increase in the incidence of sternal infection and mortality.

Adjuncts to Blood Component Therapies for the Treatment of Bleeding in the Intensive Care Unit

Patients who are critically ill following surgical or traumatic injury often present with coagulopathy as a component of the complex multisystem dysfunction that clinicians must rapidly diagnose and treat in the intensive care environment. Failure to recognize coagulopathy while volume resuscitation with crystalloid or colloid takes place, or an unbalanced transfusion strategy focused on packed red blood cell transfusion can all significantly worsen coagulopathy, leading to increased transfusion requirements and poor outcomes. Even an optimized transfusion strategy directed at correcting coagulopathy and maintaining clotting factor levels carries the risk of a number of transfusion reactions including transfusion-related acute lung injury, transfusion-related circulatory overload, anaphylaxis, and septic shock. A number of adjunctive strategies can be used either to augment a balanced transfusion approach or as alternatives to blood component therapy. Coupled with an appropriate and timely laboratory testing, this approach can quickly diagnose a patient's specific coagulopathy and work to correct it as quickly as possible, minimizing the requirement of blood transfusion and the pathophysiologic effects of excessive bleeding and fibrinolysis. We will review the literature supporting this approach and provide insight into how these approaches can be best used to care for bleeding patients in the intensive care unit. Finally, the increasing use of several novel oral anticoagulants, novel antiplatelet drugs, and low-molecular weight heparin to clinical practice has complicated the care of the coagulopathic patient when these drugs are involved. Many clinicians familiar with heparin and warfarin reversal are not familiar with the optimal way to reverse the action of these new drugs. Patients treated with these drugs for a wide variety of conditions including atrial fibrillation, stroke, coronary artery stent, deep venous thrombosis, and pulmonary embolism will present for emergency surgery and will require management of pharmacologically induced postoperative coagulopathy. We will discuss optimized strategies for reversal of these agents and strategies that are currently under development.

Topical and low-dose intravenous tranexamic acid in cyanotic cardiac surgery

Background

Coagulopathy is a major problem in surgery for cyanotic congenital heart disease. Tranexamic acid has been used both topically and systemically and plays a vital role in pediatric cardiac surgery by reducing blood loss and blood product requirement. We aimed to determine the anti-fibrinolytic effectiveness of low-dose systemic or topical tranexamic acid or a combination of both.

Methods

Seventy-five patients were divided in 3 groups of 25. Group A patients were given tranexamic acid 20 mg kg−1 intravenously after sternotomy and 20 mg kg−1 after heparin reversal. Group B patients were given tranexamic acid 50 mg kg−1 in 20 mL of saline intrapericardially before sternal closure, with the drain clamped for 20 min. Group C patients were given tranexamic acid 20 mg kg−1 intravenously after sternotomy and 50 mg kg−1 intrapericardially before sternal closure. A number of clinical variables were recorded in the first 3 postoperative days. Ventilator time, intensive care unit stay, and outcome were also recorded.

Results

Chest tube drainage and blood product requirements were lowest in group C. Blood urea and serum creatinine levels were higher in groups A and C ( p < 0.05). Intensive care unit stay and ventilator time were similar in all 3 groups. No patient died and none had a seizure or other neurological event or thromboembolic complication postoperatively.

Conclusion

The combination of low-dose intravenous and topical tranexamic acid reduces postoperative blood loss and blood product requirement without incurring neurological, renal or thromboembolic complications. We recommend the routine use of topical and low-dose systemic tranexamic acid in cyanotic pediatric cardiac surgery.

S2'-subsite variations between human and mouse enzymes (plasmin, factor XIa, kallikrein) elucidate inhibition differences by tissue factor pathway inhibitor -2 domain1-wild-type, Leu17Arg-mutant and aprotinin

Essentials Current antifibrinolytics - aminocaproic acid and tranexamic acid-can cause seizures or renal injury. KD1L17R -KT , aprotinin and tranexamic acid were tested in a modified mouse tail-amputation model. S2'-subsite variations between human and mouse factor XIa result in vastly different inhibition profiles. KD1L17R -KT reduces blood loss and D-dimer levels in mouse with unobserved seizures or renal injury.

SUMMARY

Background Using tissue factor pathway inhibitor (TFPI)-2 Kunitz domain1 (KD1), we obtained a bifunctional antifibrinolytic molecule (KD1L17R -KT ) with C-terminal lysine (kringle domain binding) and P2'-residue arginine (improved specificity towards plasmin). KD1L17R -KT strongly inhibited human plasmin (hPm), with no inhibition of human kallikrein (hKLK) or factor XIa (hXIa). Furthermore, KD1L17R -KT reduced blood loss comparable to aprotinin in a mouse liver-laceration model of organ hemorrhage. However, effectiveness of these antifibrinolytic agents in a model of hemorrhage mimicking extremity trauma and their inhibition efficiencies for mouse enzymes (mPm, mKLK or mXIa) remain to be determined. Objective To determine potential differences in inhibition constants of various antifibrinolytic agents against mouse and human enzymes and test their effectiveness in a modified mouse tail-amputation hemorrhage model. Methods/Results Unexpectedly, mXIa was inhibited with ~ 17-fold increased affinity by aprotinin (Ki ~ 20 nm) and with measurable affinity for KD1L17R -KT (Ki ~ 3 μm); in contrast, KD1WT -VT inhibited hXIa or mXIa with similar affinity. Compared with hPm, mPm had ~ 3-fold reduced affinity, whereas species specificity for hKLK and mKLK was comparable for each inhibitor. S2'-subsite variations largely accounted for the observed differences. KD1L17R -KT and aprotinin were more effective than KD1WT -VT or tranexamic acid in inhibiting tPA-induced mouse plasma clot lysis. Further, KD1L17R -KT was more effective than KD1WT -VT and was comparable to aprotinin and tranexamic acid in reducing blood loss and D-dimer levels in the mouse tail-amputation model. Conclusions Inhibitor potencies differ between antifibrinolytic agents against human and mouse enzymes. KD1L17R -KT is effective in reducing blood loss in a tail-amputation model that mimics extremity injury.