Exposure-Response Relationship of Tranexamic Acid in Cardiac Surgery

Tranexamic Acid Use in the Surgical Arena: A Narrative Review

INTRODUCTION

Tranexamic acid (TXA) is a potent antifibrinolytic drug that inhibits the activation of plasmin by plasminogen. While not a new medication, TXA has quickly gained traction across a variety of surgical subspecialties to prevent and treat bleeding. Knowledge on the use of this drug is essential for the modern surgeon to continue to provide excellent care to their patients.

METHODS

A comprehensive review of the PubMed database was conducted of articles published within the last 10 y (2014-2024) relating to TXA and its use in various surgical subspecialties. Seminal studies regarding the use of TXA older than 10 y were included from the author's archives.

RESULTS

Indications for TXA are not limited to trauma alone, and TXA is utilized across a variety of surgical subspecialties from neurosurgery to hepatic surgery to control hemorrhage. Overall, TXA is well tolerated with common dose-dependent adverse effects, including headache, nasal symptoms, dizziness, nausea, diarrhea, and fatigue. More severe adverse events are rare and easily mitigated by not exceeding a dose of 50 mg/kg.

CONCLUSIONS

The administration of TXA as an adjunct to treat trauma saves lives. The ability of TXA to induce seizures is dose dependent with identifiable risk factors, making this serious adverse effect predictable. As for the potential for TXA to cause thrombotic events, uncertainty remains. If this association is proven to be real, the risk will likely be small, since the use of TXA is still advantageous in most situations because of its efficacy for a more common concern, bleeding.

Impact of introduction of a goal directed transfusion strategy in a patient blood management program: A single cardiac surgery centre experience

BACKGROUND

The aim of this retrospective and observational study was to analyse the impact of the introduction of a goal directed transfusion (GDT) strategy based on a viscoelastic test (ROTEM®) and specific procoagulant products in a patient blood management (PBM) Program on blood product use and perioperative bleeding in a single cardiac surgery centre.

STUDY DESIGN AND METHODS

Patient population underwent cardiac surgery from 2011 to 2021 was divided in two groups based on PBM protocol used (G#11-14, years 2011-2014, G#15-21, years 2015-2021) and compared for the following variables: intraoperative and postoperative transfusions of packed red blood cell and any procoagulant products, postoperative drain blood loss volume and rate of re-exploration surgery. The second program was defined after the introduction of a GDT protocol based on viscoelastic tests and specific procoagulant products.

RESULTS

After the introduction of a GDT protocol, about 80% less amongst patients were transfused with fresh frozen plasma and any procoagulant product (p < 0.001 for both phases). Moreover, similar results were obtained with PRBC transfusions (p < 0.001) and drain blood loss volume (p = 0.006) in the postoperative phase. The main factors affecting the use of any procoagulant and PBRC transfusion in the multivariate logistic regression analysis was Group (2 versus 1, OR 0.207, p < 0.001) and preoperative haemoglobin (OR 0.728, p < 0.001), respectively.

DISCUSSION

In our experience, a GDT strategy for the diagnosis and treatment of the coagulopathy in patients undergone cardiac surgery led to a significant reduction in bleeding and transfusion.

Improved outcome with individualised antifibrinolytic therapy: what is the evidence?

Viscoelastic haemostatic testing (VHT) has been used to determine hyperfibrinolysis and hypofibrinolysis. When modified by addition of tissue plasminogen activator (tPA), VHT has been suggested to assess responses to antifibrinolytic therapy and to estimate the concentration of tranexamic acid in patients undergoing cardiac surgery. Despite some evidence that tPA-modified VHT might allow individualisation of antifibrinolytic therapy, further studies are warranted to prove its clinical benefit for postsurgical bleeding, transfusion of blood products, and thromboembolic events.

Kidney disease in trials of perioperative tranexamic acid

STUDY OBJECTIVE

To assess how kidney disease is handled in randomized trials evaluating the safety and efficacy of perioperative tranexamic acid, and to evaluate its effects across levels of kidney function.

DESIGN

Systematic review and meta-analysis of randomized controlled trials.

SETTING

We screened studies from a previous comprehensive systematic review, and updated its search of PubMed, Embase, and Cochrane CENTRAL to July 31, 2023.

PATIENTS

Patients undergoing non-obstetric surgery.

INTERVENTIONS

Intravenous tranexamic acid compared to placebo or usual care without tranexamic acid.

MEASUREMENT

We summarized the handling of kidney disease in eligibility criteria, dose adjustments for kidney function, and effects of tranexamic acid on thrombotic events, seizures, and bleeding by subgroups of kidney function.

MAIN RESULTS

We evaluated 300 trials with 53,085 participants; 45,958 participants (86.6%) were enrolled in 228 trials (76.0%) that explicitly excluded patients with kidney disease. Definitions of kidney diseased used for exclusion varied widely. Most were non-specific and some corresponded to mild disease. Only 5 trials adjusted dosing for kidney function. Meta-analysis of two large trials found tranexamic acid unlikely to substantially increase or decrease the occurrence of thrombotic events in patients with eGFR <60 mL/min/1.73m2 (RR, 0.95; 95% CI: 0.83 to 1.07) or ≥ 60 mL/min/1.73m2 (RR, 1.00; 95% CI, 0.91 to 1.11; P for subgroup difference = 0.47), but both trials excluded patients with severe kidney disease. No analysis could be performed regarding seizure risk. One large trial in noncardiac surgery reported similar reduction in bleeding across subgroups of kidney function but excluded patients with creatinine clearance <30 mL/min.

CONCLUSIONS

The large evidence base supporting perioperative tranexamic acid suffers from broad and unjustified exclusion of patients with kidney disease. Typical perioperative dosing of tranexamic acid is likely safe and effective in patients with creatinine clearance >30 mL/min, but effects in more severe kidney disease are unknown.

Point-of-care testing for tranexamic acid efficacy: a proof-of-concept study in cardiac surgical patients

BACKGROUND

Low-dose tranexamic acid (TXA) has been recently recommended for cardiopulmonary bypass (CPB) to reduce associated complications. Although point-of-care laboratory tests for TXA concentrations are unavailable, a novel TPA-test on the ClotPro® system can measure TXA-induced inhibition of fibrinolysis. We evaluated the performance of the TPA-test in vitro and in patients undergoing surgery requiring CPB.

METHODS

Blood samples were obtained from six volunteers for in vitro evaluation of tissue plasminogen activator (tPA)-triggered fibrinolysis and the effects of TXA. This was followed by an observational study in 20 cardiac surgery patients to assess clinical effects of TXA on the TPA-test.

RESULTS

Hyperfibrinolysis induced by tPA was inhibited by TXA ≥2 mg L-1 in a concentration-dependent manner, and was completely inhibited at TXA ≥10 mg L-1. In patients undergoing CPB, antifibrinolytic effect was detectable on TPA-test parameters after a 0.1 g bolus of TXA at the end of CPB, and complete inhibition of fibrinolysis was obtained with TXA ≥0.5 g. The antifibrinolytic effects of 1 g TXA on TPA-test parameters were gradually attenuated over 18 h after surgery. However, the fibrinolytic inhibition continued in four patients with estimated glomerular filtration rate (eGFR) ≤30 ml min-1 1.73 m-2. The eGFR had strong correlations with TPA-test parameters at 18 h after surgery (r=0.86-0.92; P<0.0001).

CONCLUSIONS

The TPA-test is sensitive to low concentrations of TXA and serves as a practical monitoring tool for postoperative fibrinolytic activity in cardiac surgery patients. This test might be particularly useful in patients with severe renal impairment.

Recent advances in the use of SPME for drug analysis in clinical, toxicological, and forensic medicine studies

Solid-phase microextraction (SPME) has gained attention as a simple, fast, and non-exhaustive extraction technique, as its unique features enable its use for the extraction of many classes of drugs from biological matrices. This sample-preparation approach consolidates sampling and sample preparation into a single step, in addition to providing analyte preconcentration and sample clean-up. These features have helped SPME become an integral part of several analytical protocols for monitoring drug concentrations in human matrices in clinical, toxicological, and forensic medicine studies. Over the years, researchers have continued to develop the SPME technique, resulting in the introduction of novel sorbents and geometries, which have resulted in improved extraction efficiencies. This review summarizes developments and applications of SPME published between 2016 and 2022, specifically in relation to the analysis of central nervous system drugs, drugs used to treat cardiovascular disorders and bacterial infections, and drugs used in immunosuppressive and anticancer therapies.

Use of Aprotinin versus Tranexamic Acid in Cardiac Surgery Patients with High-Risk for Excessive Bleeding (APACHE) trial: a multicentre retrospective comparative non-randomized historical study

OBJECTIVES

Following the reintroduction of aprotinin into the European market, the French Society of Cardiovascular and Thoracic Anaesthesiologists recommended its prophylactic use at half-dose for high-risk cardiac surgery patients. We examined whether the use of aprotinin instead of tranexamic acid could significantly reduce severe perioperative bleeding.

METHODS

This multicentre, retrospective, historical study included cardiac surgery patients treated with aprotinin or tranexamic acid between December 2017 and September 2020. The primary efficacy end point was the severe or massive perioperative bleeding (class 3-4 of the universal definition of perioperative bleeding). The safety secondary end points included the occurrence of thromboembolic events and all-cause mortality within 30 days after surgery.

RESULTS

Among the 693 patients included in the study, 347 received aprotinin and 346 took tranexamic acid. The percentage of patients with severe or massive bleeding was similar in the 2 groups (42.1% vs 43.6%, Adjusted odds ratio [ORadj] = 0.87, 95% confidence interval: 0.62-1.23, P = 0.44), as was the perioperative need for blood products (81.0% vs 83.2%, ORadj = 0.75, 95% confidence interval: 0.48-1.17, P = 0.20). However, the median (Interquartile range) 12 h postoperative blood loss was significantly lower in the aprotinin group (383 ml [241-625] vs 450 ml [290-730], P < 0.01). Compared to tranexamic acid, the intraoperative use of aprotinin was associated with increased risk for thromboembolic events (adjusted Hazard ratio 2.30 [95% Cl: 1.06-5.30]; P = 0.04).

CONCLUSIONS

Given the modest reduction in blood loss at the expense of a significant increase in thromboembolic adverse events, aprotinin use in high-risk cardiac surgery patients should be based on a carefully considered benefit-risk assessment.

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.

The Efficacy and Safety of a Low-Dose Tranexamic Acid Bolus-Only Protocol Compared with the Moderate-Dose Protocol in Valvular Heart Surgery

In 873 propensity score-matched pairs of patients undergoing valvular heart surgery, we compared a "moderate dose" of tranexamic acid (TXA) protocol (group 1; median TXA dose: 24 mg/kg body weight) with a 1.5-g "bolus-only" protocol (group 2; median TXA dose: 19 mg/kg body weight). The number of transfused patients was higher in group 2 than in group 1 (74.5 vs 66.0%, p < 0.001), as was the number of transfused red blood cell concentrates (p = 0.001). The risks of re-exploration and convulsive seizures were similar between groups (p > 0.50). Data indicate an impaired efficacy following the "bolus-only" protocol, without a significant safety improvement.

Tranexamic acid in endoscopic sinus and skull base surgery: A systematic review and meta-analysis

OBJECTIVE

Endoscopic sinus surgery (ESS) and endoscopic skull base surgery (ESBS) approaches have revolutionized the management of sinonasal and intracranial pathology. Maintaining surgical hemostasis is essential as bleeding can obscure the visibility of the surgical field, thus increasing surgical duration, risk of complications, and procedural failure. Tranexamic acid (TXA) acts to reduce bleeding by inhibiting fibrin degradation. This review aims to assess whether TXA improves surgical field quality and reduces intraoperative blood loss compared with control.

METHODS

We searched PubMed, MEDLINE, Embase, Web of Science, and Cochrane Library from inception until September 1, 2022. Two reviewers independently screened citations, extracted data, and assessed methodological quality using the Cochrane risk-of-bias tool for randomized trials. Data were pooled using a random-effect model, with continuous data presented as mean differences and dichotomous data presented as odds ratios.

RESULTS

Seventeen ESS randomized controlled trials (n = 1377) and one ESBS randomized controlled trial (n = 50) were reviewed. Significant improvement in surgical field quality was achieved with both systemic TXA (six studies, p < 0.00001) and topical TXA (six studies, p = 0.01) compared with the control. Systemic TXA (eight studies) and topical TXA (three studies) both achieved a significant reduction in intraoperative blood loss compared with the control (p < 0.00001). There were significant differences in operative times (p < 0.001) but no significant difference in perioperative outcomes (p = 0.30).

CONCLUSION

This meta-analysis demonstrated that the administration of TXA in ESS can improve surgical field quality and reduce intraoperative blood loss. TXA use did not result in increased perioperative complications including thrombotic events.

Perioperative hemostatic management of patients with type A aortic dissection

Coagulopathy is common in patients undergoing thoracic aortic repair for Stanford type A aortic dissection. Non-critical administration of blood products may adversely affect the outcome. It is therefore important to be familiar with the pathologic conditions that lead to coagulopathy in complex cardiac surgery. Adequate care of these patients includes the collection of the medical history regarding the use of antithrombotic and anticoagulant drugs, and a sophisticated diagnosis of the coagulopathy with viscoelastic testing and subsequently adapted coagulation therapy with labile and stable blood products. In addition to the above-mentioned measures, intraoperative blood conservation measures as well as good interdisciplinary coordination and communication contribute to a successful hemostatic management strategy.

Quantitative risk-benefit profiles of oral contraceptives, insulin sensitizers and antiandrogens for women with polycystic ovary syndrome: A model-based meta-analysis

Oral contraceptives (OCs), insulin sensitizers, and antiandrogens (AAs), alone or in combination, are commonly used for treating non-fertility indications in polycystic ovary syndrome (PCOS). However, unclear risk-benefit profiles jeopardize their appropriate clinical applications. This study aimed to quantitatively evaluate the effects of the aforementioned medications and to compare their risk-benefit profiles. Randomized controlled trials published until 14th March 2022 were searched in PubMed and Embase. A model-based meta-analysis was developed to examine the time-effect profiles of each medication. The maximal percentage change of the effect (Emax) and time to achieve half of Emax (T50) were estimated. Primary outcomes included menstruation, hirsutism score, free androgen index (FAI), body mass index (BMI), insulin sensitivity, and lipid profiles. Overall, 200 studies (9,685 patients and 385 arms) were identified for modeling. OCs performed exceptionally well in improving menstruation (Emax: 149%; T50: 7.44 weeks), hirsutism score (Emax: 66.2%; T50: 26.2 weeks), and FAI (Emax: 75.7%; T50: 0.51 weeks). However, OCs elevated the triglyceride (TG) level (Emax: 12.6%; T50:1.19 weeks). After 12-week OC treatment, the TG level of approximately 30% of patients, whose baselines were normal, exceeded the reference limit. This suggested that OC-induced dyslipidemia should be routinely monitored. The maximal BMI-lowering effect of metformin was similar to that of placebo (Emax: 3.80%); however, metformin had a shorter T50 (6.67 weeks versus 12.9 weeks). Further, active lifestyle intervention plus placebo significantly decreased BMI (Emax: 8.78%). Adding metformin to active lifestyle intervention accelerated the BMI-lowering effect within 24 weeks, whereas with the extension of this addition beyond 24 weeks, BMI did not reduce further, which indicated that benefits were limited from this prolonged addition. AAs were less potent in reducing hirsutism score (Emax: 40.2% versus 66.2%) and FAI (Emax: 34.5% versus 75.7%) compared to OCs. OC plus metformin combined OC-derived androgen-suppressing effects and metformin-derived insulin-sensitizing effects, and partially relieved the OC-induced TG increase (Emax: 9.76%). Baseline dependency was found in most clinical responses, implying that pharmacotherapies tailored based on baselines achieved more clinical improvements. This study presents new quantitative evidence on pharmacotherapies for PCOS. Currently, long-term risk-benefit profiles and emerging therapies are inadequately reported and require more further research.

Peroperative administration of tranexamic acid in sleeve gastrectomy to reduce hemorrhage: a double-blind randomized controlled trial

INTRODUCTION

In metabolic surgery, hemorrhage is the most common major complication. This study investigated whether peroperative administration of tranexamic acid (TXA) reduced the risk of hemorrhage in patients undergoing laparoscopic sleeve gastrectomy (SG).

METHODS

In this double-blind randomized controlled trial, patients undergoing primary SG in a high-volume bariatric hospital were randomized (1:1) to receive 1500-mg TXA or placebo peroperatively. Primary outcome measure was peroperative staple line reinforcement using hemostatic clips. Secondary outcome measures were peroperative fibrin sealant use and blood loss, postoperative hemoglobin, heart rate, pain, major and minor complications, length of hospital stay (LOS), side effects of TXA (i.e., venous thrombotic event (VTE)) and mortality.

RESULTS

In total, 101 patients were analyzed and received TXA (n = 49) or placebo (n = 52). There was no statistically significant difference in hemostatic clip devices used in both groups (69% versus 83%, p = 0.161). TXA administration showed significant positive changes in hemoglobin levels (millimoles per Liter; 0.55 versus 0.80, p = 0.013), in heart rate (beats per minute; -4.6 versus 2.5; p = 0.013), in minor complications (Clavien-Dindo ≤ 2, 2.0% versus 17.3%, p = 0.016), and in mean LOS (hours; 30.8 versus 36.7, p = 0.013). One patient in the placebo-group underwent radiological intervention for postoperative hemorrhage. No VTE or mortality was reported.

CONCLUSION

This study did not demonstrate a statistically significant difference in use of hemostatic clip devices and major complications after peroperative administration of TXA. However, TXA seems to have positive effects on clinical parameters, minor complications, and LOS in patients undergoing SG, without increasing the risk of VTE. Larger studies are needed to investigate the effect of TXA on postoperative major complications.

Pharmacokinetic analysis across studies to drive knowledge-integration: A tutorial on individual patient data meta-analysis (IPDMA)

Answering challenging questions in drug development sometimes requires pharmacokinetic (PK) data analysis across different studies, for example, to characterize PKs across diverse regions or populations, or to increase statistical power for subpopulations by combining smaller size trials. Given the growing interest in data sharing and advanced computational methods, knowledge integration based on multiple data sources is increasingly applied in the context of model-informed drug discovery and development. A powerful analysis method is the individual patient data meta-analysis (IPDMA), leveraging systematic review of databases and literature, with the most detailed data type of the individual patient, and quantitative modeling of the PK processes, including capturing heterogeneity of variance between studies. The methodology that should be used in IPDMA in the context of population PK analysis is summarized in this tutorial, highlighting areas of special attention compared to standard PK modeling, including hierarchical nested variability terms for interstudy variability, and handling between-assay differences in limits of quantification within a single analysis. This tutorial is intended for any pharmacological modeler who is interested in performing an integrated analysis of PK data across different studies in a systematic and thorough manner, to answer questions that transcend individual primary studies.

Guidelines on perioperative optimization protocol for the adult patient 2023

OBJECTIVE

The French Society of Anesthesiology and Intensive Care Medicine [Société Française d'Anesthésie et de Réanimation (SFAR)] aimed at providing guidelines for the implementation of perioperative optimization programs.

DESIGN

A consensus committee of 29 experts from the SFAR was convened. A formal conflict-of-interest policy was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industry funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence.

METHODS

Four fields were defined: 1) Generalities on perioperative optimization programs; 2) Preoperative measures; 3) Intraoperative measures and; 4) Postoperative measures. For each field, the objective of the recommendations was to answer a number of questions formulated according to the PICO model (population, intervention, comparison, and outcomes). Based on these questions, an extensive bibliographic search was carried out using predefined keywords according to PRISMA guidelines and analyzed using the GRADE® methodology. The recommendations were formulated according to the GRADE® methodology and then voted on by all the experts according to the GRADE grid method. As the GRADE® methodology could have been fully applied for the vast majority of questions, the recommendations were formulated using a "formalized expert recommendations" format.

RESULTS

The experts' work on synthesis and application of the GRADE® method resulted in 30 recommendations. Among the formalized recommendations, 19 were found to have a high level of evidence (GRADE 1±) and ten a low level of evidence (GRADE 2±). For one recommendation, the GRADE methodology could not be fully applied, resulting in an expert opinion. Two questions did not find any response in the literature. After two rounds of rating and several amendments, strong agreement was reached for all the recommendations.

CONCLUSIONS

Strong agreement among the experts was obtained to provide 30 recommendations for the elaboration and/or implementation of perioperative optimization programs in the highest number of surgical fields.

The efficacy and safety of intravenous administration of tranexamic acid in patients undergoing cardiac surgery: Evidence from a single cardiovascular center

BACKGROUND

The current study was performed to systemically review the efficacy and safety of tranexamic acid (TXA) in patients undergoing cardiac surgery at a single large-volume cardiovascular center.

METHODS

A computerized search of electronic databases was performed to identify all relevant studies using search terms till December 31st, 2021. The primary outcomes were postoperative blood loss and the composite incidence of mortality and morbidities during hospitalization. Secondary outcomes included postoperative massive bleeding and transfusion, postoperative recovery profiles, coagulation functions, inflammatory variables, and biomarkers of vital organ injury.

RESULTS

Database search yielded 23 qualified studies including 27,729 patients in total. Among them, 14,136 were allocated into TXA group and 13,593 into Control group. The current study indicated that intravenous TXA significantly reduced total volume of postoperative bleeding in both adult and pediatric patients, and that medium- and high-dose TXA were more effective than low-dose TXA in adult patients (P < .05). The current study also demonstrated that intravenous TXA, as compared to Control, remarkably reduced postoperative transfusion incidences and volume of red blood cell and fresh frozen plasma, and reduced postoperative transfusion incidence of platelet concentrates (PC) (P < .05) without obvious dose-effects (P > .05), but TXA did not reduce PC transfusion volume postoperatively in adult patients (P > .05). For pediatrics, TXA did not significantly reduce postoperative transfusion incidence and volume of allogenic red blood cell, fresh frozen plasma and PC (P > .05). Additionally, the current study demonstrated that intravenous TXA did not influence the composite incidence of postoperative mortality and morbidities in either adults or pediatrics during hospitalization (P > .05), and that there was no obvious dose-effect of TXA in adult patients (P > .05).

CONCLUSIONS

This current study suggested that intravenous TXA significantly reduced total volume of postoperative bleeding in both adult and pediatric patients undergoing cardiac surgery at the single cardiovascular center without increasing the composite incidence of mortality and morbidities.

Long Duration of Action of Tranexamic Acid After Cardiac Surgery in a Hemodialysis Patient: A Case Report

A 61-year-old woman with chronic renal dysfunction was scheduled to undergo aortic valve replacement. After a bolus of 1 g tranexamic acid (TXA), the TPA (tissue-plasminogen activator)-test result with the ClotPro system demonstrated extensive inhibition of fibrinolysis. Plasma TXA level decreased from 71 to 25 μg/dL at 6 hours postoperatively; however, no further decrease was observed. Although TXA levels dropped to 6.9 μg/dL after hemodialysis on postoperative day (PoD) 1, fibrinolytic shutdown on the TPA-test remained unchanged until PoD 2. In dialysis patients, low-dose TXA <1 g may be considered for reducing seizure and thromboembolic complications after cardiac surgery.

Anesthetic Considerations for Adult Patients With Both Down Syndrome and Congenital Heart Disease Undergoing Noncardiac Surgery: A Review Article

The population of adult patients with both Down syndrome and congenital heart disease is increasing due to better medical and surgical care. This cohort presents with multiple unique comorbidities, secondary to both progressions of health conditions associated with the aging of patients with Down syndrome, as well as due to pathophysiologic effects of uncorrected, corrected, or palliated congenital heart disease. These patients need frequent medical care and interventions requiring multiple anesthetics. This review focuses on the various factors relevant to the perioperative medical care of adult patients with both Down syndrome and congenital heart disease, founded on existing literature. Various anesthetic considerations for the different patterns of noncardiac and cardiac comorbidities are reviewed, and a systematic approach for the perioperative anesthetic management of these patients is presented.

Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022

BACKGROUND

Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management.

DESIGN

A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline.

RESULTS

These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%.

DISCUSSION

Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality.

CONCLUSION

All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Tranexamic acid is not associated with decreased infection risk after primary shoulder arthroplasty: a cohort study of 9276 patients

BACKGROUND

The use of tranexamic acid (TXA) is associated with less blood loss and reduced transfusion risk after shoulder arthroplasty surgery. Recent studies have shown lower odds of postoperative infection after hip or knee arthroplasty with its use. The purpose of this study was to determine whether TXA use reduces the risk of infection after primary elective shoulder arthroplasty.

METHODS

A retrospective cohort study was conducted using data from a US integrated health care system's shoulder arthroplasty registry. Patients aged 18 years who underwent primary elective anatomic total shoulder arthroplasty for osteoarthritis or primary reverse shoulder arthroplasty for rotator cuff arthropathy were included (2013-2020). We compared patients who received preoperative intravenous TXA to those who did not receive TXA by assessing the risk for revision due to deep infection within 5 years' follow-up using multivariable Cox proportional hazard regression. Interaction between TXA and diabetes status was analyzed separately.

RESULTS

The study sample included 9276 shoulder arthroplasties performed by 153 surgeons at 43 hospitals. The mean age was 70.0 years and 48% were male. The 5-year probability of revision for deep infection was 0.8% and 0.7% for patients with and without TXA, respectively. We failed to observe a difference in infection risk after adjustment for confounders and surgeon differences (hazard ratio [HR] 1.00, 95% confidence interval [CI] 0.56-1.80, P = .998). Further, no differences were observed in patients with (HR 1.64, 95% CI 0.42-6.44, P = .481) or without diabetes (HR 0.79, 95% CI 0.40-1.55, P = .488).

CONCLUSION

In a multicenter cohort of more than 9000 primary shoulder arthroplasty procedures, the use of preoperative TXA was not associated with a decrease in the 5-year probability of revision for deep infection.

Tranexamic acid is associated with improved hemostasis in elderly patients undergoing coronary-artery surgeries in a retrospective cohort study

Background

More elderly patients undergo coronary artery bypass surgery (CABG) than younger patients. Whether tranexamic acid (TA) is still effective and safe in elderly patients undergoing CABG surgeries is still unclear.

Methods

In this study, a cohort of 7,224 patients ≥70 years undergoing CABG surgery were included. Patients were categorized into the no TA group, TA group, high-dose group, and low-dose group according whether TA was administered and the dose administered. The primary endpoint was blood loss and blood transfusion after CABG. The secondary endpoints were thromboembolic events and in-hospital death.

Results

The blood loss at 24 and 48 h and the total blood loss after surgery in patients in the TA group were 90, 90, and 190 ml less than those in the no-TA group, respectively (p < 0.0001). The total blood transfusion was reduced 0.38-fold with TA administration compared to that without TA (OR = 0.62, 95% CI 0.56-0.68, p < 0.0001). Blood component transfusion was also reduced. High-dose TA administration reduced the blood loss by 20 ml 24 h after surgery (p = 0.032) but had no relationship with the blood transfusion. TA increased the risk of perioperative myocardial infarction (PMI) by 1.62-fold [p = 0.003, OR = 1.62, 95% CI (1.18-2.22)] but reduced the hospital stay time in patients who were administered TA compared to that of patients who did not receive TA (p = 0.026).

Conclusion

We revealed that elderly patients undergoing CABG surgeries had better hemostasis after TA administration but increased the risk of PMI. High-dose TA was effective and safe compared with low-dose TA administration in elderly patients undergoing CABG surgery.

A systematic review and meta-analysis of the effects of tranexamic acid in surgical procedure for intracranial meningioma

PURPOSE

During intracranial meningioma surgery, surgeons experience considerable blood loss. Tranexamic acid (TXA) is used to minimize blood loss in several neurosurgical settings. However, evidence and trials are lacking. Our objective is to establish the most recent evidence on TXA safety and efficacy in intracranial meningioma surgery.

METHODOLOGY

Based upon Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), the authors collected fully published English literature on the administration of tranexamic acid for patients undergoing intracranial meningioma surgery using the keywords ["tranexamic acid" and "meningioma"] and its synonyms from Cochrane Central Database, the WHO International Clinical Trials Registry Platform (ICTRP), ClinicalTrials.gov, and PubMed. The primary outcome of the current study was total blood loss. The secondary outcomes include individuals requiring blood transfusion, anesthesia duration, surgical duration, and complication rate. Each included studies' quality was assessed using the JADAD scale.

RESULTS

For qualitative and quantitative data synthesis, we included five RCTs (n = 321) with the mean age was 47.5 ± 11.9 years for the intervention group and 47.2 ± 11.9 years for the control group. Our meta-analysis showed that the administration of TXA is associated with decreased total blood loss of standardized mean difference (SMD) of -1.40 (95% CI [-2.49, -0.31]), anesthetic time SMD -0.36 (95% CI [-0.63, -0.09]), and blood transfusion requirements RR 0.58 (95% CI [0.34, 0.99]).

CONCLUSIONS

The current study showed that TXA was associated with reduced intraoperative blood loss and intra- and postoperative blood transfusion. However, the studies are small. More RCT studies with a greater sample size are favorable.

Tranexamic acid usage in hip fracture surgery: a meta-analysis and meta-regression analysis of current practice

INTRODUCTION

The use of tranexamic acid (TXA) in hip fracture surgery remains inconclusive. The aim of the present meta-analysis was to assess the role of TXA use in hip fracture surgery, and attempt to disclose possible factors which might influence TXA efficacy and safety.

MATERIALS AND METHODS

A systematic computerized literature search was conducted to retrieve all randomized controlled trials (RCTs) and cohort studies regarding TXA use in hip fracture surgery. Overall efficacy and safety were evaluated. Then, subgroup and meta-regression analyses were conducted to disclose the influence of geographic area, fracture type, administration route, frequency and dosage of TXA, blood transfusion threshold, and follow-up duration on the overall effect.

RESULTS

Thirty-four RCTs and 11 cohort studies were included. Patients receiving TXA had a significant decrease in the need for blood transfusion, reduced total, intra-operative and post-operative blood loss, a decrease in pre- and postoperative hemoglobin difference, without increasing thromboembolic events risk. Subgroup analysis showed that topical TXA had a lower transfusion rate compared with controls, yet the result did not reach statistical significance. Also, TXA had similar efficacy and safety profiles in patients with different frequency and dosage of TXA.

CONCLUSION

Current evidence indicated that intravenous administration of TXA could significantly reduce blood transfusion and blood loss without increasing risk of thromboembolic events. The frequency and dosage of TXA might not alter the beneficial effect. The application of topical TXA should be cautious.

Effectiveness of prophylactic doses of tranexamic acid in reducing hemorrhagic events in sleeve gastrectomy

PURPOSE

Laparoscopic sleeve gastrectomy (LSG) is currently the most common bariatric surgery in the world. Although it appears to be a safe treatment for obesity, it is still at risk of complications. The latest literature shows that postoperative bleeding occurs in 2-4% of cases, and up to 3% of cases requires reoperation for hemostasis. The aim of the study is to assess the effect of tranexamic acid (TXA) on hemorrhagic events and the reoperation rate in patients undergoing LSG.

METHODS

The study was designed as a retrospective analysis of patients undergoing LSG. We investigate the patients 6 months before and 6 months after introducing the prophylaxis doses of TXA into our bariatric protocol (non-TXA group vs TXA group).

RESULTS

Three hundred fourteen patients underwent LSG in a high-volume center from 2016 to 2017. After introducing TXA, a statistically significant reduction in the incidence of hemorrhage during surgery was observed (22.3% vs 10.8%, p = 0.006). There was a statistically significant reduction in the need for the staple line oversewing (10.2% vs 1.9%, p = 0.002). The mean operating time and the mean length of hospital stay were significantly higher in the non-TXA group than TXA group (63.1 vs 53.7 min, p < 000.1; 2.3 vs 2.1, p = 0.02). In both groups of patients, no venous thromboembolism or other complications occurred within 6 months after the surgery.

CONCLUSIONS

The prophylactic doses of TXA may be useful in reducing the hemorrhagic events during LSG. It may also shorten the length of hospital stay and the operating time.

Applications of Model-Based Meta-Analysis in Drug Development

Model-based meta-analysis (MBMA) is a quantitative approach that leverages published summary data along with internal data and can be applied to inform key drug development decisions, including the benefit-risk assessment of a treatment under investigation. These risk-benefit assessments may involve determining an optimal dose compared against historic external comparators of a particular disease indication. MBMA can provide a flexible framework for interpreting aggregated data from historic reference studies and therefore should be a standard tool for the model-informed drug development (MIDD) framework.In addition to pairwise and network meta-analyses, MBMA provides further contributions in the quantitative approaches with its ability to incorporate longitudinal data and the pharmacologic concept of dose-response relationship, as well as to combine individual- and summary-level data and routinely incorporate covariates in the analysis.A common application of MBMA is the selection of optimal dose and dosing regimen of the internal investigational molecule to evaluate external benchmarking and to support comparator selection. Two case studies provided examples in applications of MBMA in biologics (durvalumab + tremelimumab for safety) and small molecule (fenebrutinib for efficacy) to support drug development decision-making in two different but well-studied disease areas, i.e., oncology and rheumatoid arthritis, respectively.Important to the future directions of MBMA include additional recognition and engagement from drug development stakeholders for the MBMA approach, stronger collaboration between pharmacometrics and statistics, expanded data access, and the use of machine learning for database building. Timely, cost-effective, and successful application of MBMA should be part of providing an integrated view of MIDD.

Does Tranexamic Acid Reduce the Blood Loss in Various Surgeries? An Umbrella Review of State-of-the-Art Meta-Analysis

Background: Tranexamic acid (TXA) has been applied in various types of surgery for hemostasis purposes. The efficacy and safety of TXA are still controversial in different surgeries. Guidelines for clinical application of TXA are needed. Materials and method: We systematically searched multiple medical databases for meta-analyses examining the efficacy and safety of TXA. Types of surgery included joint replacement surgery, other orthopedic surgeries, cardiac surgery, cerebral surgery, etc. Outcomes were blood loss, blood transfusion, adverse events, re-operation rate, operative time and length of hospital stay, hemoglobin (Hb) level, and coagulation function. Assessing the methodological quality of systematic reviews 2 (AMSTAR 2) and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) were used for quality assessment of the included meta-analyses. Overlapping reviews were evaluated by calculating the corrected covered area (CCA). Result: In all, we identified 47 meta-analyses, of which 44 of them were of "high" quality. A total of 319 outcomes were evaluated, in which 58 outcomes were assessed as "high" quality. TXA demonstrates significant hemostatic effects in various surgeries, with lower rates of blood transfusion and re-operation, shorter operative time and length of stay, and higher Hb levels. Besides, TXA does not increase the risk of death and vascular adverse events, but it is a risk factor for seizure (a neurological event) in cardiac surgery. Conclusion: Our study demonstrates that TXA has a general hemostatic effect with very few adverse events, which indicates TXA is the recommended medication to prevent excessive bleeding and reduce the blood transfusion rate. We also recommend different dosages of TXA for different types of adult surgery. However, we could not recommend a unified dosage for different surgeries due to the heterogeneity of the experimental design. Systematic Review Registration: clinicaltrials.gov/, identifier CRD42021240303.

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.

Efficacy and safety of tranexamic acid in the treatment of adult melasma: An updated meta-analysis of randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

Tranexamic acid (TXA) is a novel treatment option for melasma; however, no consensus exists on its use. This study evaluates the efficacy and safety of TXA for melasma.

METHODS

A comprehensive literature review was conducted to search for randomized controlled trials comparing TXA alone, TXA as adjuvant to routine treatment and placebo. Changes in the Melasma Area Severity Index (MASI)/modified MASI (mMASI) between pre- and post-treatment and between a certain melasma treatment and TXA were the primary outcomes. Twenty-four trials comparing oral, topical or intradermal TXA with routine treatment were included in the meta-analysis.

RESULTS AND DISCUSSION

The change in MASI/mMASI scores at 4 (MD, 3.58; 95% confidence interval (CI), 2.15-5.01), 8 (MD, 5.08; 95% CI, 3.34-6.81), 12 (MD, 4.89; 95% CI, 3.80-5.97) and 16 (MD, 6.55; 95% CI, 2.62-10.48) weeks after treatment was all less than the baseline scores, regardless of the delivery route. The reduction in the MASI/mMASI scores between TXA adjuvant and routine treatment at 4 (MD, -0.43; 95% CI, -0.79 to -0.08), 8 (MD, -0.81; 95% CI, -1.09 to -0.54), 12 (MD, -1.10; 95% CI, -1.78 to -0.43) and 16 (MD, -1.12; 95% CI, -1.51 to -0.74) weeks was significant. However, the superiority of TXA was not detected when the topical or intradermal route was adopted. No serious adverse events occurred with the use of TXA.

WHAT IS NEW AND CONCLUSION

These results suggest that oral TXA is an available, effective and safe alternative treatment for melasma.