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

The Impact of Tranexamic Acid Administration in Reduction Mammaplasty: A Systematic Review

BACKGROUND

Previous studies demonstrated the effectiveness and safety of tranexamic acid (TXA) in several surgical specialties. Recent publications suggested that TXA may also be beneficial in plastic surgery, including breast procedures.

OBJECTIVE

The aim of this study is to evaluate the impact of TXA in reduction mammaplasty by assessing several intraoperative and postoperative outcomes and the safety of its administration.

METHODS

A systematic search was conducted according to PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analysis) guidelines on several online databases. Studies evaluating the outcomes of TXA administration in patients undergoing reduction mammaplasty, regardless of TXA dose and administration route were eligible for inclusion. Only studies with a control group were included. Risk-of-bias assessment was conducted using Cochrane and MINORS (Methodological Index for Non-Randomized Studies) tools.

RESULTS

Our systematic review included 7 studies: 3 randomized controlled trials and 4 retrospective cohorts involving 1234 female patients (2232 breasts), 741 of whom received TXA (60%). Four studies used topical TXA, 2 used intravenous (IV) TXA, one used locally infiltrated TXA, and another combined locally infiltrated TXA with IV TXA. Four studies demonstrated benefits from TXA administration, whereas 3 studies did not. Topical TXA used just before wound closure resulted in a 42% reduction in drain fluid output and a 10-times reduction in major hematoma. The administration of IV TXA during induction resulted in a 12-times reduction in major and minor hematoma. The combined use of IV and locally infiltrated TXA reduced intraoperative blood loss. No adverse effects were reported.

CONCLUSIONS

There is scientific evidence suggesting TXA may be effective and safe in reduction mammaplasty.

Meta-analysis: the prophylactic use of tranexamic acid to reduce blood loss during caesarean delivery

INTRODUCTION

The 2022 national guideline on The Prevention and Management of Primary Postpartum Haemorrhage (PPH) recommended consideration of prophylactic tranexamic acid (TXA) for women who are at high PPH risk undergoing caesarean section (CS). This meta-analysis reviews the basis for this recommendation.

METHOD

PubMed, OVID Medline, EMBASE, Science Citation Index, Scopus, CENTRAL, and ClinicalTrials.gov were searched (from inception to January 2024) for randomised controlled trials comparing prophylactic intravenous TXA with placebo or no treatment in women undergoing CS who received a uterotonic. Our main outcome was PPH > 1L. Secondary outcomes included estimated mean blood loss, blood transfusion, drop in haemoglobin, the need for additional uterotonics, or surgical intervention. Adverse effects of TXA were also assessed.

RESULTS

Sixty-one studies including 25,098 women were identified, and 12,446 received prophylactic TXA. Patients who received prophylactic TXA had significantly reduced likelihood of PPH > 1L (RR, 0.47; 95% CI, 0.38 to 0.59), reduced estimated mean blood loss (MD 185.86 ml, 95% CI 159.14-212.59), and reduced drop in Hb (MD 0.84g/dl, 95% CI 0.72, 0.95). There was a significant reduction in need for additional uterotonics (RR 0.47, 95% CI 0.39-0.57) or surgical intervention (RR 0.54, 95% CI 0.30-0.95).

CONCLUSION

The reduced risk of PPH > 1L was greatest in patients at higher risk of bleeding. The greatest risk reduction was seen in smaller studies and in studies undertaken in developing economies. Prophylactic TXA administration is effective at reducing the incidence of PPH > 1L at CS. The clinical benefit of universal prophylaxis is questionable; women who are high risk of PPH are more likely to derive benefit.

Tranexamic Acid in Mohs Micrographic Surgery: A Systematic Review

BACKGROUND

Tranexamic acid (TXA) is an antifibrinolytic that has historically been used to treat menorrhagia and bleeding disorders. Exploration of its use in procedures has grown, and it has shown promise in its ability to achieve hemostasis with low risk to patients. Analysis of its use in Mohs micrographic surgery (MMS) is warranted due to its potential superiority to traditional methods of achieving hemostasis (direct pressure, electrocoagulation, and sutures).

OBJECTIVE

To perform a systematic review of studies which evaluate the efficacy and safety profile of topical application or subcutaneous injection of TXA and analyze as it applies to MMS.

MATERIALS AND METHODS

A comprehensive literature search was conducted using the PubMed database to identify relevant studies using the search terms: "tranexamic acid" OR "TXA." The search was performed up to December 1, 2023.

RESULTS

Tranexamic acid has a strong safety profile, and its effectiveness in achieving hemostasis is well-demonstrated. Tranexamic acid has reduced risk of bleeding complications compared with traditional methods of achieving hemostasis.

CONCLUSION

An extensive review of the literature has yielded positive results, suggesting the potential of TXA in improving patient outcomes, reducing surgical time, decreasing intraoperative and postoperative bleeding, and increasing overall patient satisfaction.

The Effectiveness and Safety of Tranexamic Acid in Treating Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis

Background/Objectives: Tranexamic acid (TXA) is a synthetic antifibrinolytic agent that inhibits plasminogen activation, thereby reducing bleeding. The aim of this systematic review was to investigate its role in aneurysmal subarachnoid hemorrhage (SAH)-a condition indicated by bleeding between two layers of brain tissue-to stop rebleeding and improve patient outcomes. Methods: We conducted a systematic review and meta-analysis of randomized controlled trials from 1981 to 2024, focusing on the efficacy and safety of TXA in treating aneurysmal SAH (PROSPERO registration: CRD42024504834). Our comprehensive search of the PubMed and Cochrane Library databases identified studies assessing TXA at dosages of 3 to 6 g per day and examining outcomes such as rebleeding incidence, mortality, thromboembolic events, and other adverse effects. Results: From six included studies involving 2990 patients, the meta-analysis showed TXA largely lowered rebleeding risk (OR 0.54 95% CI 0.43-0.68; p < 0.00001), yet mortality rates were not largely different between the TXA group (385 out of 1201), and the control group (344 out of 1193) (OR 1.18 95% CI 0.98-1.40; p = 0.07). Likewise, there were no large differences in the occurrence of cerebral ischemia and blood clot-related events between the groups. Conclusions: TXA effectively reduces the risk of rebleeding in SAH patients, but does not significantly alter mortality or the incidence of thromboembolic complications. These findings back the careful use of TXA and demonstrate the need for further research to better its clinical use and assess long-term impacts.

Exploratory Randomised Trial of Tranexamic Acid to Decrease Postoperative Delirium in Adults Undergoing Lumbar Fusion: A trial stopped early

Background

Postoperative delirium may be mediated by perioperative systemic- and neuro-inflammation. By inhibiting the pro-inflammatory actions of plasmin, tranexamic acid (TXA) may decrease postoperative delirium. To explore this hypothesis, we modified an ongoing randomised trial of TXA, adding measures of postoperative delirium, cognitive function, systemic cytokines, and astrocyte activation.

Methods

Adults undergoing elective posterior lumbar fusion randomly received intraoperative intravenous TXA (n=43: 10 mg kg-1 loading dose, 2 mg kg-1 h-1 infusion) or Placebo (n=40). Blood was collected pre- and at 24 h post-operatively (n=32) for biomarkers of systemic inflammation (cytokines) and astrocyte activation (S100B). Participants had twice daily delirium assessments using the 3-minute diagnostic interview for Confusion Assessment Method (n=65). Participants underwent 4 measures of cognitive function preoperatively and during post-discharge follow-up.

Results

Delirium incidence in the TXA group (7/32=22%) was not significantly less than in the Placebo group (11/33=33%); P=0.408, absolute difference=11%, relative difference=33%, effect size = -0.258 (95% CI -0.744 to 0.229). In the Placebo group (n=16), delirium severity was associated with the number of instrumented vertebral levels (P=0.001) and with postoperative interleukin -8 and -10 concentrations (P=0.00008 and P=0.005, respectively) and these associations were not significantly modified by TXA. In the Placebo group, delirium severity was associated with S100B concentration (P=0.0009) and the strength of the association was decreased by TXA (P=0.002).

Conclusions

A potential 33% relative decrease in postoperative delirium incidence justifies an adequately powered clinical trial to determine if intraoperative TXA decreases delirium in adults undergoing lumbar fusion.

A Retrospective Comparative Analysis on the Effect of Tranexamic Acid to Reduce Perioperative Blood Loss in Patients Undergoing Cervical Spine Surgery

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVE

The purpose of this study is to assess the impact of intravenous TXA on blood loss outcomes in anterior, posterior, and combined approaches for elective cervical spine surgery.

SUMMARY OF BACKGROUND DATA

Tranexamic acid (TXA) has been shown to reduce blood loss in a variety of operations, such as lumbar spine surgery. However, limited studies have evaluated the efficacy of TXA in cervical spine surgery.

METHODS

We performed a retrospective review of a single surgeon's elective cervical spine operations between September 2011 and March 2017. Patients were divided into 3 groups: anterior approach, posterior approach, or combined approach. Patients were then further subdivided into TXA versus control groups based on whether they received TXA treatment. We performed multiple linear regressions to assess the relationship between the use of TXA and other dependent variables (number of vertebral levels treated, need for a vertebral corpectomy) on total perioperative blood loss, intraoperative estimated blood loss, postoperative drain output, total operative time, postoperative change in hemoglobin, and occurrence of transfusion and/or postoperative deep venous thrombus (DVT).

RESULTS

We found that the use of TXA statistically significantly reduced total perioperative blood loss ( P =0.04) and postoperative drain output ( P =0.004) in posterior surgical approach cervical spine surgery but did not statistically significantly impact any blood loss variables in anterior or combined surgical approaches to elective cervical spine surgery. The use of TXA was a significant predictor for a decrease in intraoperative ( P =0.02) and postoperative ( P <0.01) blood loss.

CONCLUSIONS

This study found that TXA statistically significantly decreased total blood loss and postoperative drain output when controlling for multiple confounding factors.

LEVEL OF EVIDENCE

Level III.

Tranexamic acid - a promising hemostatic agent with limitations: a narrative review

Tranexamic acid (TXA) is a synthetic antifibrinolytic agent that has been used for several decades to reduce blood loss during surgery and after trauma. TXA was traditionally used to reduce bleeding in various clinical settings such as menorrhagia, hemophilia, or other bleeding disorder. Numerous studies have demonstrated the efficacy of TXA in reducing blood loss and the need for transfusions. Interest in the potential applications of TXA beyond its traditional use has been growing recently, with studies investigating the use of TXA in postpartum hemorrhage, cardiac surgery, trauma, neurosurgery, and orthopedic surgery. Despite its widespread use and expanding indications, data regarding the safe and appropriate use of TXA is lacking. Recent clinical trials have found various potential risks and limitations in the long-term benefits of TXA. This narrative review summarizes the clinical applications and limitations of TXA.

Global trends in research of venous thromboembolism associated with lower limb joint arthroplasty: A bibliometric analysis

This study aims to visualize publications related to venous thromboembolism (VTE) and lower limb joint arthroplasty to identify research frontiers and hotspots, providing references and guidance for further research. We retrieved original articles published from 1985 to 2022 and their recorded information from the Web of Science Core Collection. The search strategy used terms related to knee or hip arthroplasty and thromboembolic events. Microsoft Excel was used to analyze the annual publications and citations of the included literature. The rest of the data were analyzed using the VOSviewer, citespace and R and produced visualizations of these collaborative networks. We retrieved 3543 original articles and the results showed an overall upward trend in annual publications. The United States of America had the most significant number of publications (Np) and collaborative links with other countries. McMaster University had the greatest Np. Papers published by Geerts WH in 2008 had the highest total link strength. Journal of Arthroplasty published the most articles on the research of VTE associated with lower limb joint arthroplasty. The latest research trend mainly involved "general anesthesia" "revision" and "tranexamic acid." This bibliometric study revealed that the research on VTE after lower limb joint arthroplasty is developing rapidly. The United States of America leads in terms of both quantity and quality of publications, while European and Canadian institutions and authors also make significant contributions. Recent research focused on the use of tranexamic acid, anesthesia selection, and the VTE risk in revision surgeries.

Total blood loss and early clinical outcomes under different tranexamic acid regimes in total knee arthroplasty

BACKGROUND

Many different regimes of intravenous and local tranexamic acid (TXA) reduce total blood loss (TBL) in patients undergoing total knee arthroplasty (TKA). However, the most effective TXA regime in reducing blood loss might not be most beneficial for the patient. The aim of the present study was to investigate the effect of commonly used TXA regimes on blood loss and on early clinical outcomes.

METHODS

We performed this monocentric retrospective study in patients undergoing primary TKA. Primary outcome was the estimated TBL. Secondary outcomes were the rates of adverse events (AE) as well as the range of motion (ROM), mobility and pain intensity during the first three physiotherapy sessions (PTS).

RESULTS

We analysed the data of 1250 TKAs. 5 different TXA regimes were applied. TBL (mean ± SE) was 953 ± 64 ml (2xiv), 999 ± 19 ml (2xiv + 1xlocal), 1075 ± 19 ml (1xiv + 1xlocal), 1191 ± 39 ml (1xlocal) and 1241 ± 48 ml (1xiv) (p < 0.01). In the linear regression model for TBL a lower number of TXA applications was a predictor for increased blood loss (p < 0.01). AE rates were lowest under 2xiv (0%) and 2xiv + 1xlocal (4.8%). Highest mobility and lowest pain intensity were observed under 1x iv and 2x iv. The largest portions of fully mobile patients on day three were observed under 1xiv (100%), 2xiv (100%) and 2xiv + 1local TXA (86.9%).

CONCLUSION

Our results suggest that multiple applications of TXA are more effective in decreasing blood loss than excessive dosing of TXA. Interestingly, local use of TXA might be associated with higher pain intensity and decreased mobility on the first days after surgery.

The Critical Blood-Sparing Effect of Tranexamic Acid (TXA) in Liposuction: A Systematic Review and Meta-Analysis

Introduction

Tranexamic acid (TXA) has been used to improve bleeding outcomes in many surgical procedures. However, its blood-sparing effect in liposuction is not well established.

Methods

A systematic literature search was performed using PubMed, Embase, Cumulated Index to Nursing and Allied Health Literature (CINAHL), Cochrane Central, ClinicalTrials.gov, and WorldWideScience.org databases from their inception to October 8, 2021, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The authors focused on 3 main topics: 1) TXA, 2) liposuction, and 3) complications. We included articles evaluating the potential blood-sparing effects of TXA in liposuction. Studies were excluded if they were systematic review articles or protocol papers, animal studies, conference abstracts, survey studies, or non-English publications.

Results

A total of 711 articles were identified, with 1 retrospective and 4 prospective (3 randomized) studies meeting our inclusion criteria. TXA was used in various forms: administered intravenously either on induction or after the procedure, mixed into the tumescent solution, or infiltrated into the liposuction sites after lipoaspiration. A significantly smaller reduction in hematocrit was noted in the TXA group compared with that in the non-TXA group (p<0.001) despite a significantly greater amount of lipoaspirate removed in the TXA group (p<0.001). Patients in non-TXA cohorts experienced adverse effects (such as seroma and need for transfusion) that were not seen in TXA cohorts.

Conclusion

TXA use in patients undergoing liposuction seems to be associated with a beneficial blood-sparing effect, which may enhance safety in this population. Future studies should aim to determine the optimal route and dosing for TXA in liposuction.

Evidence Based Medicine

Level IV.

Use of Intravenous Tranexamic Acid in Patients Undergoing Plastic Surgery: Implications and Recommendations per a Systematic Review and Meta-Analysis

With increasing interest in aesthetic plastic procedures, the event of blood loss has compromised patients' safety and satisfaction. Tranexamic acid (TXA) is a drug used for the reduction of blood loss during surgical procedures. This systematic review aims to evaluate the clinical efficacy and safety of TXA in aesthetic plastic surgery for the reduction of bleeding and related complications. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Electronic databases PubMed, EMBASE, Cochrane Library, and Google Scholar were searched. The medical subject headings (MeSH) keywords used for data extraction were ("TXA," OR "tranexamic acid,") AND ("plastic surgery," OR "aesthetic surgery," OR "rhinoplasty," OR "blepharoplasty,") AND ("blood loss" OR "bleeding" OR "TBL") AND ("Edema" OR "ecchymosis"). A combination of these MeSH terms was used in the literature search. The timeline of research was set from 2015 to January 2024. A total of 7380 research articles were identified from the above-mentioned databases, and only 13 research articles met the inclusion criteria. There was a significant difference in total blood loss (TBL) among patients who had undergone plastic surgery procedures while on TXA as compared to a placebo (mean difference = -6.02; Cl: -1.07 to -0.16; p > 0.00001), and heterogeneity was found (degrees of freedom (df) = 9; I2 = 97%). Only two studies reported the average ecchymosis scores after TXA among interventions in comparison to the placebo group. This review provides evidence that TXA lowers TBL, ecchymosis, edema, and anemia during cosmetic surgery without significantly increasing thromboembolic consequences.

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.

Tranexamic acid decreases transfusion requirements during the modified pi-plasty procedure for sagittal craniosynostosis

The aim of our study was to evaluate the effectiveness of intraoperative tranexamic acid (TXA) administration in decreasing transfusion needs in patients undergoing modified pi-plasty. A retrospective study was performed using a population of 59 patients who underwent modified pi-plasty, wherein patients who received TXA during surgery (study group, n = 26) were compared with patients who did not receive TXA (control group, n = 33). The primary study endpoints were intraoperative red blood cell substitution (%), postoperative red blood cell substitution (%), total red blood cell substitution (%), and hematocrit variation. Perioperative administration of TXA significantly decreased the total red blood cell substitution (62.90% vs 86.70%; p = 0.002) and resulted in a higher postoperative hematocrit (29.47% vs 27.53%; p = 0.060). In conclusion, perioperative administration of TXA significantly decreased blood transfusion requirements in patients with sagittal craniosynostosis undergoing modified pi-plasty.

Collaborative science in action: A 20 year perspective from the Health and Environmental Sciences Institute (HESI) Cardiac Safety Committee

The Health and Environmental Sciences Institute (HESI) is a nonprofit organization dedicated to resolving global health challenges through collaborative scientific efforts across academia, regulatory authorities and the private sector. Collaborative science across non-clinical disciplines offers an important keystone to accelerate the development of safer and more effective medicines. HESI works to address complex challenges by leveraging diverse subject-matter expertise across sectors offering access to resources, data and shared knowledge. In 2008, the HESI Cardiac Safety Committee (CSC) was established to improve public health by reducing unanticipated cardiovascular (CV)-related adverse effects from pharmaceuticals or chemicals. The committee continues to significantly impact the field of CV safety by bringing together experts from across sectors to address challenges of detecting and predicting adverse cardiac outcomes. Committee members have collaborated on the organization, management and publication of prospective studies, retrospective analyses, workshops, and symposia resulting in 38 peer reviewed manuscripts. Without this collaboration these manuscripts would not have been published. Through their work, the CSC is actively addressing challenges and opportunities in detecting potential cardiac failure modes using in vivo, in vitro and in silico models, with the aim of facilitating drug development and improving study design. By examining past successes and future prospects of the CSC, this manuscript sheds light on how the consortium's multifaceted approach not only addresses current challenges in detecting potential cardiac failure modes but also paves the way for enhanced drug development and study design methodologies. Further, exploring future opportunities and challenges will focus on improving the translational predictability of nonclinical evaluations and reducing reliance on animal research in CV safety assessments.

Can local infiltration analgesia supplemented with tranexamic acid reduce blood loss during total knee arthroplasty?

PURPOSE

The aim of this study was to investigate the efficacy of TXA supplemented with local infiltration analgesia (LIA) for reducing blood loss in patients undergoing total knee replacement.

MATERIALS

A retrospective study of 530 individuals with a mean age of 71.44 years was performed after posterior stabilized total knee arthroplasty. Patients were divided into three groups according to the method of bleeding control: I - patients without an additional bleeding protocol (control group); II - patients receiving IV TXA (TXA group); and III - patients receiving the exact TXA protocol plus intraoperative local infiltration analgesia (TXA + LIA group). Blood loss was measured according to the maximal decrease in Hb compared to the preoperative Hb level.

RESULTS

The mean hospitalization duration was 7.02 (SD 1.34) days in the control group, 6.08 (SD 1.06) days in the TXA group, and 5.56 (SD 0.79) in the TXA + LIA group. The most significant decrease in haemoglobin was found in the control group, which was an average of 30.08%. The average decrease in haemoglobin was 25.17% (p < 0.001) in the TXA group and 23.67% (p < 0.001) in the TXA + LIA group. A decrease in the rate of allogeneic blood transfusions was observed: 24.4% in the control group, 9.9% in the TXA group, and 8% in the TXA + LIA group (p < 0.01).

CONCLUSIONS

Compared to the separate administration of tranexamic acid, the combination of perioperative administration with local infiltration analgesia significantly reduced blood loss in patients after total knee replacement.

Safety of tranexamic acid in surgically treated isolated spine trauma

BACKGROUND

Tranexamic acid (TXA), a synthetic antifibrinolytic drug, effectively reduces blood loss by inhibiting plasmin-induced fibrin breakdown. This is the first study in the United Kingdom to investigate the effectiveness of TXA in the surgical management of isolated spine trauma.

AIM

To assess the safety of TXA in isolated spine trauma. The primary and secondary outcomes are to assess the rate of thromboembolic events and to evaluate blood loss and the incidence of blood transfusion, respectively.

METHODS

This prospective observational study included patients aged ≥ 17 years with isolated spine trauma requiring surgical intervention over a 6-month period at two major trauma centers in the United Kingdom.

RESULTS

We identified 67 patients: 26 (39%) and 41 (61%) received and did not receive TXA, respectively. Both groups were matched in terms of age, gender, American Society of Anesthesiologists grade, and mechanism of injury. A higher proportion of patients who received TXA had a subaxial cervical spine injury classification or thoracolumbar injury classification score > 4 (74% vs 56%). All patients in the TXA group underwent an open approach with a mean of 5 spinal levels involved and an average operative time of 203 min, compared with 24 patients (58%) in the non-TXA group who underwent an open approach with an average of 3 spinal levels involved and a mean operative time of 159 min. Among patients who received TXA, blood loss was < 150 and 150-300 mL in 8 (31%) and 15 (58%) patients, respectively. There were no cases of thromboembolic events in any patient who received TXA.

CONCLUSION

Our study demonstrated that TXA is safe for isolated spine trauma. It is challenging to determine whether TXA effectively reduces blood loss because most surgeons prefer TXA for open or multilevel cases. Further, larger studies are necessary to explore the rate, dosage, and mode of administration of TXA.

The role of fibrosis in cardiomyopathies: An opportunity to develop novel biomarkers of disease activity

Cardiomyopathies encompass a spectrum of heart disorders with diverse causes and presentations. Fibrosis stands out as a shared hallmark among various cardiomyopathies, reflecting a common thread in their pathogenesis. This prevalent fibrotic response is intricately linked to the consequences of dysregulated extracellular matrix (ECM) remodeling, emphasizing its significance in the development and progression the disease. This review explores the ECM involvement in various cardiomyopathies and its impact on myocardial stiffness and fibrosis. Additionally, we discuss the potential of ECM fragments as early diagnosis, prognosis, and risk stratification. Biomarkers deriving from turnover of collagens and other ECM proteins hold promise in clinical applications. We outline current clinical management, future directions, and the potential for personalized ECM-targeted therapies with specific focus on microRNAs. In summary, this review examines the role of the fibrosis in cardiomyopathies, highlighting the potential of ECM-derived biomarkers in improving disease management with implications for precision medicine.

Use of platelet transfusions and tranexamic acid in patients with myelodysplastic syndromes: A clinical practice survey

AIM

Thrombocytopenia and bleeding are common in myelodysplastic syndromes (MDS), but optimal management is unknown. We conducted a survey to identify current clinical practice regarding platelet transfusion (PLT-T) and tranexamic acid (TXA) to inform future trial design.

METHOD

A 25-question survey was distributed to members of the ALLG from December 2020 to July 2021.

RESULTS

Sixty-four clinicians across Australia, New Zealand and Singapore responded. Clinicians treated a median of 15 MDS patients annually. Twenty-nine (45%) reported having institutional guidelines regarding prophylactic PLT-T. Although 60 (94%) said they would consider using TXA, most (58/64; 91%) did not have institutional guidelines. Clinical scenarios showed prophylactic PLT-T was more likely administered for patients on disease-modifying therapy (49/64; 76%, commonest threshold <10 × 109 /L) or with minor bleeding (32/64 [50%] transfusing at threshold <20 × 109 /L, 23/64 [35%] at <10 × 109 /L). For stable untreated patients, 29/64 (45%) would not give PLT-T and 32/64 (50%) would. Most respondents (46/64; 72%) were interested in participating in trials in this area. Potential barriers included resource limitations, funding and patient/clinician acceptance.

CONCLUSION

Real-world management of MDS-related thrombocytopenia varies and there is a need for clinical trials to inform practice.

Does Patient Blood Management Affect Outcomes in Metastatic Spine Tumour Surgery? A Review of Current Concepts

STUDY DESIGN

Narrative review.

OBJECTIVE

The spine is the most common site of metastases, associated with decreased quality of life. Increase in metastatic spine tumour surgery (MSTS) has caused us to focus on the management of blood, as blood loss is a significant morbidity in these patients. However, blood transfusion is also not without its own risks, and hence this led to blood conservation strategies and implementation of a concept of patient blood management (PBM) in clinical practise focusing on these patients.

METHODS

A narrative review was conducted and all studies that were related to blood management in metastatic spine disease as well as PBM surrounding this condition were included.

RESULTS

A total of 64 studies were included in this review. We discussed a new concept of patient blood management in patients undergoing MSTS, with stratification to pre-operative and intra-operative factors, as well as anaesthesia and surgical considerations. The studies show that PBM and reduction in blood transfusion allows for reduced readmission rates, lower risks associated with blood transfusion, and lower morbidity for patients undergoing MSTS.

CONCLUSION

Through this review, we highlight various pre-operative and intra-operative methods in the surgical and anaesthesia domains that can help with PBM. It is an important concept with the significant amount of blood loss expected from MSTS.

LEVEL OF EVIDENCE

Not applicable.

Therapeutic efficacy of tranexamic acid on traumatic brain injury: a systematic review and meta-analysis

OBJECTIVE

Tranexamic acid (TXA) demonstrates therapeutic efficacy in the management of traumatic brain injury (TBI). The objective of this systematic review and meta-analysis was to evaluate the safety and effectiveness of TXA in patients with TBI.

METHODS

The databases, namely PubMed, Embase, Web of Science, and Cochrane Library databases, were systematically searched to retrieve randomized controlled trials (RCTs) investigating the efficacy of TXA for TBI from January 2000 to November 2023.

RESULTS

The present meta-analysis incorporates ten RCTs. Compared to the placebo group, administration of TXA in patients with TBI resulted in a significant reduction in mortality (P = 0.05), hemorrhage growth (P = 0.03), and volume of hemorrhage growth (P = 0.003). However, no significant impact was observed on neurosurgery outcomes (P = 0.25), seizure occurrence (P = 0.78), or pulmonary embolism incidence (P = 0.52).

CONCLUSION

The administration of TXA is significantly associated with reduced mortality and hemorrhage growth in patients suffering from TBI, while the need of neurosurgery, seizures, and incidence of pulmonary embolism remains comparable to that observed with placebo.

The effect of tranexamic acid on synovium of patients undergoing arthroplasty and anterior cruciate ligament reconstruction surgery

Preoperative hemorrhage can be reduced using anti-fibrinolytic medicine tranexamic acid (TXA). During surgical procedures, local administration is being used more and more frequently, either as an intra-articular infusion or as a perioperative rinse. Serious harm to adult soft tissues can be detrimental to the individual since they possess a weak ability for regeneration. Synovial tissues and primary fibroblast-like synoviocytes (FLS) isolated from patients were examined using TXA treatment in this investigation. FLS is obtained from rheumatoid arthritis (RA), osteoarthritis (OA), and anterior cruciate ligament (ACL)-ruptured patients. The in vitro effect of TXA on primary FLS was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability assays for cell death, annexin V/propidium iodide (PI) staining for apoptotic rate, real-time PCR for p65 and MMP-3 expression, and enzyme-linked immunosorbent assay (ELISA) for IL-6 measurement. MTT assays revealed a significant decrease in cell viability in FLS of all groups of patients following treatment with 0.8-60 mg/ml of TXA within 24 h. There was a significant increase in cell apoptosis after 24 h of exposure to TXA (15 mg/ml) in all groups, especially in RA-FLS. TXA increases the expression of MMP-3 and p65 expression. There was no significant change in IL-6 production after TXA treatment. An increase in receptor activator of nuclear factor kappa-Β ligand (RANK-L) production was seen only in RA-FLS. This study demonstrates that TXA caused significant synovial tissue toxicity via the increase in cell death and elevation of inflammatory and invasive gene expression in FLS cells.

Updated Clinical Review: Perioperative Use of Tranexamic Acid in Orthopedics and Other Surgeries

Tranexamic acid is a well-known antifibrinolytic that has numerous clinical indications, and it is efficacious and safe in many perioperative scenarios including patients with some thrombotic risks. However, further studies that characterize clinical outcomes concerning dosing, timing, and routes in combination are needed in ultra high-risk populations.

Tranexamic Acid Causes Chondral Injury Through Chondrocytes Apoptosis Induced by Activating Endoplasmic Reticulum Stress

PURPOSE

To investigate whether tranexamic acid (TXA) is cytotoxic in chondrocyte and cartilage tissues, as well as explore the mechanisms behind the possible toxicity in detail.

METHODS

We detected the cell viability of chondrocytes in vitro and the change of morphology and specific in vivo contents of cartilage after TXA treatment. Furthermore, we detected apoptosis in cartilage. We used apoptosis-specific staining, reactive oxygen species detection, mitochondrial membrane potential detection, flow cytometry, and western blot for apoptosis detection. Finally, we detected the activation of endoplasmic reticulum stress (ERS) in TXA-treated chondrocytes to clarify the mechanism behind chondrocyte apoptosis.

RESULTS

TXA presented an increasing toxic effect with increasing concentrations, especially in the 100 mg/mL group. In addition, we found that 50 mg/mL and 100 mg/mL TXA significantly increased apoptosis in cartilage and subchondral bone. TXA could induce chondrocyte apoptosis in cell and protein levels with reactive oxygen species generation and mitochondrial membrane depolarization. An apoptosis inhibitor could inhibit the induced apoptosis. Next, TXA induced calcium overload in chondrocytes and increased ERS-specific protein expression, whereas ERS inhibitor blocked ERS activation and further inhibited chondrocyte apoptosis.

CONCLUSIONS

We concluded that TXA had a toxic effect on chondrocytes by inducing apoptosis through ERS activation, especially in 50 mg/mL and 100 mg/mL groups. We recommend TXA concentrations of less than 50 mg/mL in joint surgeries.

CLINICAL RELEVANCE

It is still unclear whether TXA has a toxic effect on cartilage when topically used in joint surgeries. The concentration also varies. This study provides additional evidence that TXA at high concentrations will cause cartilage damage, which will help to provide a new understanding of the clinical administration of TXA.

The Effects of Tranexamic Acid in Breast Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Tranexamic acid (TXA) is used in trauma and surgical settings. Its role in reducing postoperative blood loss in breast surgery remains unclear. The primary objective of this study was to determine the effect of TXA on postoperative blood loss in breast surgery.

METHODS

Searches of the PubMed, Ovid MEDLINE, Embase, CINAHL, and Cochrane Central Register of Controlled Trials databases were performed from inception to April 3, 2020. Inclusion criteria were any retrospective reviews, prospective cohort studies, and randomized controlled trials that administered TXA (topical or intravenously) in the context of breast surgery. Quality of studies were evaluated using the risk of bias in randomized trials tool and the risk of bias in nonrandomized studies of interventions tool. Data were pooled, and a meta-analysis was performed.

RESULTS

In total, seven studies were included, representing 1226 patients (TXA, 632 patients; control, 622 patients). TXA was administered as follows: topically (20 mL of 25 mg/mL TXA intraoperatively; n =258 patients), intravenously (1 to 3 g perioperatively; n = 743 patients), or both (1 to 3 g daily up to 5 days postoperatively; n = 253 patients). TXA administration reduced hematoma formation in breast surgery (risk ratio, 0.48; 95% CI, 0.32 to 0.73), with no effect on drain output (mean difference, -84.12 mL; 95% CI, -206.53 to 38.29 mL), seroma formation (risk ratio, 0.92; 95% CI, 0.60 to 1.40), or infection rates (risk ratio, 1.01; 95% CI, 0.46 to 2.21). No adverse effects were reported.

CONCLUSION

The use of TXA in breast surgery is a safe and effective modality with low-level evidence that it reduces hematoma rates without affecting seroma rates, postoperative drain output, or infection rates.

Does the Use of Tranexamic Acid in Patients Who Have Preoperative Coagulopathy Undergoing Total Joint Arthroplasty Normalize Their Risk of Complications? A Matched Equivalence Analysis

BACKGROUND

While patients who have a preoperative coagulopathy have an increased risk of perioperative blood loss, tranexamic acid (TXA) has been shown to decrease the risk of complications in this subset. However, a direct comparison of the use of TXA in coagulopathic and noncoagulopathic patients has not been performed. In addition to comparing differences in decreases in hemoglobin, transfusions, and complications, this study examined whether the use of TXA in coagulopathic patients normalized the risk of blood loss relative to matched noncoagulopathic patients.

METHODS

We performed a retrospective review of 230 patients who had a preoperative coagulopathy and underwent primary total joint arthroplasty (127 hips, 103 knees) from 2012 to 2019 and received TXA. Coagulopathy was defined as international normalized ratio >1.2, partial thromboplastin time >35 seconds, or platelet count <150,000/mL (mL). A matched comparison group of 689 patients who did not have a coagulopathy and received TXA was identified. A 2 1-sided test (TOST) analysis was performed to test for equivalence. Assuming a clinically relevant difference of 1 g/dL in postoperative decrease in hemoglobin, the equivalence margin was set as ±1 g/dL between the groups.

RESULTS

When comparing coagulopathic and noncoagulopathic patients, total hip arthroplasty (THA) patients had no differences in hemoglobin, but had an increased reported estimated blood loss (243 versus 207 mL, P = .040) as well as an increased percent of patients requiring blood transfusions (11.8 versus 5.32%, P = .022). Total knee arthroplasty (TKA) patients had no differences in hemoglobin, estimated blood loss, or percent of patients requiring transfusion. There were no differences in medical or surgical complications for both groups for THA and TKA patients. Equivalence testing for both groups revealed statistical significance that THA and TKA coagulopathic patients receiving TXA had an equivalent risk of blood loss compared to noncoagulopathic patients receiving TXA.

CONCLUSION

Coagulopathic patients receiving TXA and undergoing THA had an increased risk of receiving a transfusion; however, there were no differences in complications for both TKA and THA, as well as a normalized risk of blood loss when compared to noncoagulopathic patients.

LEVEL OF EVIDENCE

III.

Tranexamic acid for percutaneous nephrolithotomy

BACKGROUND

Percutaneous nephrolithotomy (PCNL) is the gold standard for the treatment of large kidney stones but comes with an increased risk of bleeding compared to other treatments, such as ureteroscopy and shock wave lithotripsy. Tranexamic acid (TXA) is an antifibrinolytic agent that has been used to reduce bleeding complications in other settings.

OBJECTIVES

To assess the effects of TXA in individuals with kidney stones undergoing PCNL.

SEARCH METHODS

We performed a comprehensive literature search of the Cochrane Library, PubMed (including MEDLINE), Embase, Scopus, Global Index Medicus, trials registries, other sources of the grey literature, and conference proceedings. We applied no restrictions on the language of publication nor publication status. The latest search date was 11 May 2023.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared treatment with PCNL with administration of TXA to placebo (or no TXA) for patients ≥ 18 years old.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies and abstracted data. Primary outcomes were: blood transfusion, stone-free rate (SFR), and thromboembolic events (TEEs). Secondary outcomes were: adverse events (AEs), secondary interventions, major surgical complications, minor surgical complications, unplanned hospitalizations or readmissions, and hospital length of stay (LOS). We performed statistical analyzes using a random-effects model. We rated the certainty of evidence (CoE) according to the GRADE approach using a minimally contextualized approach with predefined thresholds for minimally clinically important differences (MCIDs).

MAIN RESULTS

We analyzed 10 RCTs assessing the effect of systemic TXA in PCNL versus placebo (or no TXA) with 1883 randomized participants. Eight studies were published as full text. One was published in abstract proceedings, but it was separated into two separate studies for the purpose of our analyzes. Average stone surface area ranged 3.45 to 6.62 cm2. We also found a single RCT published in full text assessing the effects of topical TXA in PCNL versus placebo (or no TXA) with 400 randomized participants, the results of which are further described in the review. Here we focus only on the results of TXA used systemically. Blood transfusion - Based on a representative baseline risk of 5.7% for blood transfusions taken from a large presentative observational studies, systemic TXA may reduce blood transfusions (risk ratio (RR) 0.45, 95% confidence interval (CI) 0.27 to 0.76; I2 = 28%; 9 studies, 1353 participants; low CoE). We assumed an MCID of ≥ 2%. Based on 57 participants per 1000 with placebo (or no TXA) being transfused, this corresponds to 31 fewer (from 42 fewer to 14 fewer) participants being transfused per 1000. Stone-free rate - Based on a representative baseline risk of 75.7% for SFR, systemic TXA may increase SFRs (RR 1.11, 95% CI 0.98 to 1.27; I2 = 62%; 4 studies, 603 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 757 participants per 1000 being stone free with placebo (or no TXA), this corresponds to 83 more (from 15 fewer to 204 more) stone-free participants per 1000. Thromboembolic events - There is probably no difference in TEEs (risk difference (RD) 0.00, 95% CI -0.01 to 0.01; I2 = 0%; 6 studies, 841 participants; moderate CoE). We assumed an MCID of ≥ 2%. Since there were no thromboembolic events in intervention and/or control groups in 5 out of6 studies, we opted to assess a risk difference with systemic TXA for this outcome. Adverse events - Systemic TXA may increase AEs (RR 5.22, 95% CI 0.52 to 52.72; I2 = 75%; 4 studies, 602 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 23 participants per 1000 with placebo (or no TXA) having an adverse event, this corresponds to 98 more (from 11 fewer to 1000 more) participants with adverse events per 1000. Secondary interventions - Systemic TXA may have little to no effect on secondary interventions (RR 1.15, 95% CI 0.84 to 1.57; I2 = 0%; 2 studies, 319 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 278 participants per 1000 with placebo (or no TXA) having a secondary intervention, this corresponds to 42 more (from 44 fewer to 158 more) participants with secondary interventions per 1000. Major surgical complications - Based on a representative baseline risk for major surgical complications of 4.1%, systemic TXA may reduce major surgical complications (RR 0.36, 95% CI 0.21 to 0.62; I2 = 0%; 5 studies, 733 participants; moderate CoE). We assumed an MCID of ≥ 2%. Based on 41 participants per 1000 with placebo (or no TXA) having a major surgical complication, this corresponds to 26 fewer (from 32 fewer to 16 fewer) participants with major surgical complications per 1000. Minor surgical complications - Systemic TXA may reduce minor surgical complications (RR 0.71, 95% CI 0.45 to 1.10; I2 = 76%; 5 studies, 733 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 396 participants per 1000 with placebo (or no TXA) having a minor surgical complication, this corresponds to 115 fewer (from 218 fewer to 40 more) participants with minor surgical complications per 1000. Unplanned hospitalizations or readmissions - We are very uncertain how unplanned hospitalizations or readmissions are affected (RR 1.55, 95% CI 0.45 to 5.31; I2 = not applicable; 1 study, 189 participants; very low CoE). We assumed an MCID of ≥ 2%. Hospital length of stay - Systemic TXA may reduce hospital LOS (mean difference 0.52 days lower, 95% CI 0.93 lower to 0.11 lower; I2 = 98%; 7 studies, 1151 participants; low CoE). We assumed an MCID of ≥ 0.5 days.

AUTHORS' CONCLUSIONS

Based on 10 RCTs with substantial methodological limitations that lowered all CoE of effect, we found that systemic TXA in PCNL may reduce blood transfusions, major and minor surgical complications, and hospital LOS, as well as improve SFRs; however, it may increase AEs. We are uncertain about the effects of systemic TXA on other outcomes. Findings of this review should assist urologists and their patients in making informed decisions about the use of TXA in the setting of PCNL.

Efficacy of tranexamic acid supplemented with local infiltration analgesia in reducing blood loss in patients undergoing unicompartmental knee arthroplasty

This study aimed to investigate the efficacy of tranexamic acid supplemented with local infiltration analgesia in reducing blood loss in patients undergoing unicompartmental knee arthroplasty (UKA). This retrospective study was conducted on 176 individuals with a mean age of 64.27 (standard deviation [SD], 7.16) years undergoing unicompartmental cemented knee arthroplasty. The patients were divided into three groups according to patient blood management: I, patients without additional bleeding protocol (control group); II, patients intravenously administered tranexamic acid (TXA) (TXA group); and III, patients with exact TXA protocol combined with intraoperative local infiltration analgesia (LIA) (TXA + LIA group). Blood loss was measured as a substitute for blood loss by the maximal haemoglobin (Hb) drop compared with the preoperative Hb level. The mean Hb drops for the control, TXA, and TXA + LIA groups were 2.24 (16.0%), 2.14 (15.4%), and 1.81 (12.6%) g/dl, respectively. The mean hospitalisation days for patients in the control, TXA, and TXA + LIA groups were 5.91 (SD 1.24), 5.16 (SD 0.95), and 4.51 (SD 0.71) days, respectively. The combination of TXA with LIA reduces perioperative blood loss for patients after UKA.

A prophylactic TXA administration effectively reduces the risk of intraoperative bleeding during open management of pelvic and acetabular fractures

This study aimed to evaluate the efficacy of perioperative intravenous TXA in reducing blood loss in pelvic and acetabular fracture patients managed surgically. The study included 306 consecutive patients, divided as: group I, 157 patients who did not receive perioperative infusion of TXA and group II, 149 patients who received perioperative TXA. The perioperative blood test results and complication rates were compared between the two groups. The average perioperative hematocrit was higher during the preoperative period than during the first, second and third postoperative day in both groups. In the estimated blood loss between the two groups, there was a significant difference of 1391 (± 167.49) ml in group I and 725 (± 403.31) ml in group II respectively (p = 0.02). No significant difference was seen in the total of intraoperative transfusion units as well as in the total units of blood transfused. There was a reduced level of postoperative hemoglobin (9.28 ± 17.88 g/dl in group I and 10.06 ± 27.57 g/dl in group II compared to the values obtained in preoperative investigations (10.4 ± 2.37 g/dl in group I and 11.4 ± 2.08 g/dl in group II); with a significant difference in postoperative transfusion rates (p = 0.03). Therefore, the use of TXA effectively reduces the risk of intraoperative bleeding during open management of pelvic and acetabular fractures.

The effect of different hemostatic agents following dental extraction in patients under oral antithrombotic therapy: a network meta-analysis

This network meta-analysis was done to thoroughly evaluate the available literature on the use of different hemostatic agents for dental extraction in patients under oral antithrombotic therapy, aiming to identify the agent with the best/worst performance in bleeding control. Considering that such patients have a higher risk of bleeding, choosing the right hemostatic is essential. Twenty-three randomized clinical trials articles were included after completing the literature search. Cyanoacrylate tissue adhesive showed a reduction in the odds of postoperative bleeding events compared with conventional methods (i.e., gauze/cotton pressure, sutures), with a tendency toward a statistical significance (OR 0.03, P = 0.051). Tranexamic acid was the only agent that demonstrated a significantly lower risk of developing postoperative bleeding events (OR 0.27, P = 0.007). Interestingly, chitosan dental dressing and collagen plug had the shortest time to reach hemostasis. However, they ranked last among all hemostatic agents, regarding bleeding events, revealing higher odds than conventional measures. Therefore, it is concluded that the use of cyanoacrylate tissue adhesive and tranexamic acid gives favorable results in reducing postoperative bleeding events following dental extractions. Although chitosan dental dressing and collagen exhibited a faster time to reach hemostasis, they led to a higher occurrence of bleeding events.

Modern use of tranexamic acid in facial plastic surgery

PURPOSE OF REVIEW

Although tranexamic acid is commonly used in surgical fields such as obstetrics, orthopedics, and trauma, its utilization in facial plastic surgery is a recently emerging concept, and studies examining its potential impact have been few. This review highlights how tranexamic acid may be employed during facial plastic procedures and the promising impact it may have.

RECENT FINDINGS

Tranexamic acid is primarily being studied in rhinoplasties and rhytidectomies, with intravenous administration and local infiltration being the most common routs of application, respectively. During rhinoplasties, tranexamic acid has the potential to improve the visualization of the surgical field by decreasing blood loss and to improve postoperative edema and ecchymosis. For rhytidectomies, on the contrary, it may shorten time to attain hemostasis, lessen the rate of hematoma formation, and lead to lower surgical drain output. Its efficacy is preserved at low doses, and significant medication side effects have not been reported after facial plastic procedures.

SUMMARY

Altogether, tranexamic acid may present a valuable adjuvant to facial plastic surgery, as it could increase both surgeon and patient satisfaction while exhibiting a benign safety profile.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pharmacological interventions for the prevention of bleeding in people undergoing definitive fixation or joint replacement for hip, pelvic and long bone fractures

BACKGROUND

Pelvic, hip, and long bone fractures can result in significant bleeding at the time of injury, with further blood loss if they are treated with surgical fixation. People undergoing surgery are therefore at risk of requiring a blood transfusion and may be at risk of peri-operative anaemia. Pharmacological interventions for blood conservation may reduce the risk of requiring an allogeneic blood transfusion and associated complications.

OBJECTIVES

To assess the effectiveness of different pharmacological interventions for reducing blood loss in definitive surgical fixation of the hip, pelvic, and long bones.

SEARCH METHODS

We used a predefined search strategy to search CENTRAL, MEDLINE, PubMed, Embase, CINAHL, Transfusion Evidence Library, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform (ICTRP) from inception to 7 April 2022, without restrictions on language, year, or publication status. We handsearched reference lists of included trials to identify further relevant trials. We contacted authors of ongoing trials to acquire any unpublished data.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of people who underwent trauma (non-elective) surgery for definitive fixation of hip, pelvic, and long bone (pelvis, tibia, femur, humerus, radius, ulna and clavicle) fractures only. There were no restrictions on gender, ethnicity, or age. We excluded planned (elective) procedures (e.g. scheduled total hip arthroplasty), and studies published since 2010 that had not been prospectively registered. Eligible interventions included: antifibrinolytics (tranexamic acid, aprotinin, epsilon-aminocaproic acid), desmopressin, factor VIIa and XIII, fibrinogen, fibrin sealants, and non-fibrin sealants.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and risk of bias, and extracted data. We assessed the certainty of the evidence using GRADE. We did not perform a network meta-analysis due to lack of data.

MAIN RESULTS

We included 13 RCTs (929 participants), published between 2005 and 2021. Three trials did not report any of our predefined outcomes and so were not included in quantitative analyses (all were tranexamic acid versus placebo). We identified three comparisons of interest: intravenous tranexamic acid versus placebo; topical tranexamic acid versus placebo; and recombinant factor VIIa versus placebo. We rated the certainty of evidence as very low to low across all outcomes. Comparison 1. Intravenous tranexamic acid versus placebo Intravenous tranexamic acid compared to placebo may reduce the risk of requiring an allogeneic blood transfusion up to 30 days (RR 0.48, 95% CI 0.34 to 0.69; 6 RCTs, 457 participants; low-certainty evidence) and may result in little to no difference in all-cause mortality (Peto odds ratio (Peto OR) 0.38, 95% CI 0.05 to 2.77; 2 RCTs, 147 participants; low-certainty evidence).  It may result in little to no difference in risk of participants experiencing myocardial infarction (risk difference (RD) 0.00, 95% CI -0.03 to 0.03; 2 RCTs, 199 participants; low-certainty evidence), and cerebrovascular accident/stroke (RD 0.00, 95% CI -0.02 to 0.02; 3 RCTs, 324 participants; low-certainty evidence).  We are uncertain if there is a difference between groups for risk of deep vein thrombosis (Peto OR 2.15, 95% CI 0.22 to 21.35; 4 RCTs, 329 participants, very low-certainty evidence), pulmonary embolism (Peto OR 1.08, 95% CI 0.07 to 17.66; 4 RCTs, 329 participants; very low-certainty evidence), and suspected serious drug reactions (RD 0.00, 95% CI -0.03 to 0.03; 2 RCTs, 185 participants; very low-certainty evidence). No data were available for number of red blood cell units transfused, reoperation, or acute transfusion reaction. We downgraded the certainty of the evidence for imprecision (wide confidence intervals around the estimate and small sample size, particularly for rare events), and risk of bias (unclear or high risk methods of blinding and allocation concealment in the assessment of subjective measures), and upgraded the evidence for transfusion requirement for a large effect.  Comparison 2. Topical tranexamic acid versus placebo We are uncertain if there is a difference between topical tranexamic acid and placebo for risk of requiring an allogeneic blood transfusion (RR 0.31, 95% CI 0.08 to 1.22; 2 RCTs, 101 participants), all-cause mortality (RD 0.00, 95% CI -0.10 to 0.10; 1 RCT, 36 participants), risk of participants experiencing myocardial infarction (Peto OR 0.15, 95% CI 0.00 to 7.62; 1 RCT, 36 participants), cerebrovascular accident/stroke (RD 0.00, 95% CI -0.06 to 0.06; 1 RCT, 65 participants); and deep vein thrombosis (Peto OR 1.11, 95% CI 0.07 to 17.77; 2 RCTs, 101 participants).  All outcomes reported were very low-certainty evidence. No data were available for number of red blood cell units transfused, reoperation, incidence of pulmonary embolism, acute transfusion reaction, or suspected serious drug reactions. We downgraded the certainty of the evidence for imprecision (wide confidence intervals around the estimate and small sample size, particularly for rare events), inconsistency (moderate heterogeneity), and risk of bias (unclear or high risk methods of blinding and allocation concealment in the assessment of subjective measures, and high risk of attrition and reporting biases in one trial). Comparison 3. Recombinant factor VIIa versus placebo   Only one RCT of 48 participants reported data for recombinant factor VIIa versus placebo, so we have not presented the results here.

AUTHORS' CONCLUSIONS

We cannot draw conclusions from the current evidence due to lack of data. Most published studies included in our analyses assessed the use of tranexamic acid (compared to placebo, or using different routes of administration).  We identified 27 prospectively registered ongoing RCTs (total target recruitment of 4177 participants by end of 2023). The ongoing trials create six new comparisons: tranexamic acid (tablet + injection) versus placebo; intravenous tranexamic acid versus oral tranexamic acid; topical tranexamic acid versus oral tranexamic acid; different intravenous tranexamic acid dosing regimes; topical tranexamic acid versus topical fibrin glue; and fibrinogen (injection) versus placebo.

Synthesis, Characterization, Properties, and Biomedical Application of Chitosan-Based Hydrogels

The prospective applications of chitosan-based hydrogels (CBHs), a category of biocompatible and biodegradable materials, in biomedical disciplines such as tissue engineering, wound healing, drug delivery, and biosensing have garnered great interest. The synthesis and characterization processes used to create CBHs play a significant role in determining their characteristics and effectiveness. The qualities of CBHs might be greatly influenced by tailoring the manufacturing method to get certain traits, including porosity, swelling, mechanical strength, and bioactivity. Additionally, characterization methods aid in gaining access to the microstructures and properties of CBHs. Herein, this review provides a comprehensive assessment of the state-of-the-art with a focus on the affiliation between particular properties and domains in biomedicine. Moreover, this review highlights the beneficial properties and wide application of stimuli-responsive CBHs. The main obstacles and prospects for the future of CBH development for biomedical applications are also covered in this review.

Impact of trauma teams on high grade liver injury care: a two-decade propensity score approach study in Taiwan

High-grade liver laceration is a common injury with bleeding as the main cause of death. Timely resuscitation and hemostasis are keys to the successful management. The impact of in-hospital trauma system on the quality of resuscitation and management in patients with traumatic high-grade liver laceration, however, was rarely reported. We retrospectively reviewed the impact of team-based approach on the quality and outcomes of high-grade traumatic liver laceration in our hospital. Patients with traumatic liver laceration between 2002 and 2020 were enrolled in this retrospective study. Inverse probability of treatment weighting (IPTW)-adjusted analysis using the propensity score were performed. Outcomes before the trauma team establishment (PTTE) and after the trauma team establishment (TTE) were compared. A total of 270 patients with liver trauma were included. After IPTW adjustment, interval between emergency department arrival and managements was shortened in the TTE group with a median of 11 min (p < 0.001) and 28 min (p < 0.001) in blood test reports and duration to CT scan, respectively. Duration to hemostatic treatments in the TTE group was also shorter by a median of 94 min in patients receiving embolization (p = 0.012) and 50 min in those undergoing surgery (p = 0.021). The TTE group had longer ICU-free days to day 28 (0.0 vs. 19.0 days, p = 0.010). In our study, trauma team approach had a survival benefit for traumatic high-grade liver injury patients with 65% reduction of risk of death within 72 h (Odds ratio (OR) = 0.35, 95% CI = 0.14-0.86) and 55% reduction of risk of in-hospital mortality (OR = 0.45, 95% CI = 0.23-0.87). A team-based approach might contribute to the survival benefit in patients with traumatic high-grade liver laceration by facilitating patient transfer from outside the hospital, through the diagnostic examination, and to the definitive hemostatic procedures.

Current status of hemostatic agents, their mechanism of action, and future directions

The bleeding problem might seem straightforward, but it involves a plethora of complex biochemical pathways and responses. Hemorrhage control remains one of the leading causes of “preventable deaths” worldwide. The past few decades have seen a wide range of biomaterials and their derivatives targeted to serve as hemostatic agents, but none can be deemed as an ideal solution. In this review, we have highlighted the current diversity in hemostatic agents and their modalities. We have enclosed a comprehensive outlook of the proposed solutions and their clinical performance so far. In addition to these, several promising compositions are still in their infancy or developmental phases. The inclusion of novel upcoming nanocomposites has further widened the potencies of existing formulations as well.

Janus Self-Propelled Chitosan-Based Hydrogel Spheres for Rapid Bleeding Control

Uncontrolled hemorrhage is a major cause of potentially preventable death in civilian trauma nowadays. Considerable concern has been given to the development of efficient hemostats with high blood absorption, self-propelled property, and Ca2+ release ability, for irregularly shaped and noncompressible hemorrhage. Herein, Janus self-propelled chitosan-based hydrogel with CaCO3 (J-CMH@CaCO3 ) is developed by partial ionic crosslinking of carboxylated chitosan (CCS) and Ca2+ , gravity settlement, and photopolymerization, followed by removing the shell of CCS. The obtained J-CMH@CaCO3 is further used as a hemostat powered by the internal CaCO3 and coordinated protonated tranexamic acid (J-CMH@CaCO3 /T). Bubbles are generated and detached to provide the driving force, accompanied by the release of Ca2+ . The two aspects work in synergy to accelerate clot formation, endowing the J-CMH@CaCO3 /T with excellent hemostatic efficiency. The J-CMH@CaCO3 /T presents high blood absorption, favorable blood-clotting ability, desired erythrocyte and platelet aggregation, and acceptable hemocompatibility and cytocompatibility. In rodent and rabbit bleeding models, the J-CMH@CaCO3 /T exhibits the most effective hemostasis to the best knowledge of the authors, wherein the hemorrhage is rapidly halted within 39 s. It is believed that the J-CMH@CaCO3 /T with self-propelled property opens up a new avenue to design high-performance hemostats for clinical application.

Impact of intra-articular injection with tranexamic acid on total blood loss and postoperative pain after arthroscopic rotator cuff repair surgery

Objectives

To evaluate the impact of intra-articular injection with tranexamic acid (TXA) on total blood loss (TBL) and postoperative pain after arthroscopic rotator cuff repair (ARCR).

Methods

This study retrospectively included patients with full-thickness rotator cuff tears who underwent shoulder ARCR surgery in Taizhou hospital, China, between January 2018 and December 2020. Patients received 10 ml (100 mg/ml) of intra-articular TXA injection (TXA group) or 10 ml of normal saline (non-TXA group) after the incision was sutured. The primary variable was the type of drug injected into the shoulder joint at the end of the operation. The primary outcome were perioperative TBL and postoperative pain [measured by visual analog scale (VAS)]. The secondary outcomes were differences in red blood cell count, hemoglobin count, hematocrit, platelet count.

Results

A total of 162 patients were included, 83 patients in TXA group and 79 patients in non-TXA group. Notably, patients in TXA group were more likely to have lower TBL volume [261.21 (175.13-506.67) ml vs. 382.41 (236.11-593.31), P = 0.025], and postoperative VAS score ≤ 2 within 24 h (P = 0.031) compared with those in non-TXA group. In addition, the median hemoglobin count difference was significantly lower in TXA group than that of in non-TXA group (P = 0.045), while, the differences in median counts of red blood cell, hematocrit, and platelet between the two groups were comparable (all P > 0.05).

Conclusion

Intra-articular injection of TXA might reduce the TBL and degree of postoperative pain within 24 h after shoulder arthroscopy.

Outcomes of 4-factor Prothrombin Complex Concentrate in Patients With Liver Disease and Nonvitamin K Antagonist-Related Coagulopathy: A Retrospective Study

The administration of 4-factor prothrombin complex concentrate (4F-PCC) has expanded beyond its Food and Drug Administration (FDA)-approved indication for the emergent reversal of vitamin K antagonists (VKAs). Therefore, this study aimed to evaluate the risks and benefits associated with the expanded use of 4F-PCC. We conducted a single-center retrospective review of 4F-PCC administrations at our university hospital. Of the 159 patients who received 4F-PCC, 76% (n = 121) and 24% (n = 38) received it for the FDA-approved indication in the vitamin K-related coagulopathy (VKA) group and for expanded use in the nonvitamin K-related coagulopathy (nVKA) group, respectively. The expanded use of 4F-PCC was associated with a less robust reduction in the international normalized ratio (INR) (INR of -0.7 ± 1.3 vs INR of -1.6 ± 1.8, P = .002), and fewer patients in the nVKA group achieved a postadministration INR of less than1.5 (11% vs 79%, P = .001) than those in the VKA group. Furthermore, the 30-day mortality rate was significantly higher in the nVKA cohort than in the VKA cohort (42% vs 20%, P = .04). Notably, based on our data, underlying differences in the patient's comorbidities, particularly advanced liver disease, may have contributed to the observed outcome variations, including mortality rate. Therefore, factors, including comorbidities and the underlying etiology of coagulopathy, should be considered when deciding on the expanded use of 4F-PCC. Further research is needed to better understand the potential risks and benefits of 4F-PCC in expanded use scenarios, and the clinical decision to use 4F-PCC outside its FDA-approved indication should be made carefully, considering this information.

Combination of Intravenous and Intra-Articular Application of Tranexamic Acid and Epsilon-Aminocaproic Acid in Primary Total Knee Arthroplasty: A Prospective Randomized Controlled Trial

OBJECTIVE

There were limited randomized controlled trials (RCTs) of epsilon-aminocaproic acid (EACA) versus tranexamic acid (TXA) in total knee arthroplasty (TKA). The aim of the study was to compare the efficacy and safety of TXA and EACA in the combination of intravenous (IV) and intra-articular (IA) administration on reducing blood loss in patients following primary TKA.

METHODS

From January 2020 to January 2021, a total of 181 patients undergoing a primary unilateral TKA were enrolled in this prospective randomized controlled trial. Patients in the TXA group (n = 90) received 20 mg/kg of intravenous TXA preoperatively, 1 g of intra-articular TXA intraoperatively, and three doses of 20 mg/kg intravenous TXA at 0, 3, 6 h postoperatively. Patients in the EACA group (n = 91) received 120 mg/kg of intravenous EACA preoperatively, 2 g of intra-articular EACA intraoperatively, and three doses of 40 mg/kg intravenous EACA at 0, 3, 6 h postoperatively. The primary outcomes were total blood loss (TBL), transfusion rates and drop of hemoglobin (HB) level. The secondary outcomes included postoperative hospital stays and postoperative complications. The chi-square tests and Fisher's exact tests were utilized to compare categorical variables, while the independent-samples t-tests and Mann-Whitney tests were used to compare continuous variables.

RESULTS

The patients who received TXA averaged less TBL than the patients who received EACA (831.83 ml vs 1065.49 ml, P = 0.015), and HB drop in TXA group was generally less than that of EACA group on postoperative day 1 and 3 (20.84 ± 9.48 g/L vs 24.99 ± 9.40 g/L, P = 0.004; 31.28 ± 11.19 vs 35.46 ± 12.26 g/L, P = 0.047). The length of postoperative stays in EACA group was 3.66 ± 0.81 day, which is longer than 2.62 ± 0.68 day in TXA group (P < 0.001). No transfusions were required in either group. The risk of nausea and vomiting in TXA group was significantly higher than that in EACA group (11/90 vs 0/91, P < 0.01).

CONCLUSION

Although the TBL and HB drop were slightly greater in EACA group, these results were not clinically important, given that no transfusions were required. EACA could be an alternative to TXA, especially for patients with severe nausea and vomiting after using TXA postoperatively. Further studies are needed to adjust dosage of EACA to make better comparison of the two drugs.

Use of Tranexamic Acid to Reduce PostOperative Bleeding in Orthopaedic Oncology

Background: Orthopaedic oncology often causes major blood losses that may put at risk patients’ hemodynamic balance and their overall clinical stability. To this date, transfusion therapy still represents the pivotal treatment to counterbalance the reduction in hemoglobin levels which occur after surgery. Although effective, transfusions are expensive and inevitably associated with a number of complications and therefore other solutions, such as procoagulative drugs, could play an important role to prevent massive blood losses.Material and methods: We reviewed the clinical intercourse of 37 patients who underwent major bone resection due to malignant tumors of the lower limb. Cases were divided in two different groups: group G1 consisting of 12 patients treated intraoperatively with tranexamic acid and group G2 which was made of 25 controls.Results: On average, patients treated with tranexamic acid (G1) required transfusion of 3.9 concentrated blood cells units during surgery and 0.9 units during the postoperative course. Other patients (G2), for their part, required on average 3.1 units intraoperatively and 2.1 units postoperatively. No significant difference was found in intraoperative transfusion rate (p=0.402). Instead, postoperative transfusions were significantly less frequent for patients treated with tranexamic acid (p=0.023). None of the 12 patients treated with tranexamic acid had evidence of Deep Vein Thrombosis.Conclusion: Our outcomes indicate that the use of TXA was effective in reducing blood losses also for major surgical interventions in orthopedic oncology.

The Effect of Topical Tranexamic Acid on Intraoperative Blood Loss in Patients Undergoing Posterior Lumbar Laminectomy and Discectomy: A Randomized, Double-Blind, Controlled Trial Study

STUDY DESIGN

Randomized, double-blind, controlled trial study.

PURPOSE

This study aimed to evaluate the safety and efficacy of topical tranexamic acid (TXA) on intraoperative blood loss (IBL) in patients that have degenerative lumbar canal stenosis and undergo posterior lumbar laminectomy and discectomy.

OVERVIEW OF LITERATURE

The volume of IBL is directly proportional to potential surgical complications. Recent reports have shown that the topical use of antifibrinolytic drugs, such as TXA, during surgery might decrease IBL and improve patient outcomes.

METHODS

A total of 104 patients with lumbar canal stenosis were enrolled in this randomized, double blinded clinical trial. Participants were randomized and divided into two groups: TXA (54 cases) and control (50 cases). In the TXA group, a TXA solution was used for washing and soaking, whereas, in the control group, irrigation of wound was with normal saline. IBL, pre- and postoperative coagulative studies, operation time, conventional hemostatic agent usage, systemic complications, and length of hospitalization were consecutively recorded. All participants were followed for an additional two months to gather data on their recovery status and time to return to work (RTW).

RESULTS

At baseline, there was no difference in clinical or lab findings, between the groups. IBL and use of hemostatic agents were significantly decreased in TXA group, as compared to the control group (p=0.001 and p=0.011, respectively). Systemic complications, length of hospitalization, and RTW were not significantly different between groups (p=0.47, p=0.38, and p=0.08, respectively).

CONCLUSIONS

This study showed that topical use of TXA during surgery may decrease IBL and minimize the use of hemostatic materials during posterior midline-approach laminectomy and discectomy, without increasing the potential for complications seen with intravenous TXA usage.

The effect of tranexamic acid on myocardial injury in cardiac surgical patients: a systematic review and meta-analysis

Tranexamic acid (TXA) is one of the most commonly used antifibrinolytic agents for surgical patients. However, the effect of TXA on myocardial injury remains controversial. We systemically reviewed literature regarding the effectiveness of TXA on myocardial injury in patients who have undergone a cardiac surgery. We included all randomized controlled trials (RCTs) comparing TXA and control (saline) in cardiac surgical patients. Relevant studies were identified by a comprehensive electronic literature search from database inception to 15 August 2021. A standardized data extraction form was used to collect methodological and outcome variables from each eligible study. We conducted a meta-analysis to estimate the pooled effect size of TXA administration on myocardial injury. In total, eight RCTs were identified, with 292 patients in the TXA group, and 241 patients in saline or control group. The meta-analysis demonstrated that patients in the TXA group had lower levels of CK-MB and cTnI within 24 h postoperatively (CK-MB: P  = 0.005; cTnI: P  = 0.01), compared with the saline group. No significant difference was found with respect to AST level ( P  = 0.71) between TXA and saline groups within 24 h postoperatively. TXA administration was found to be associated with less myocardial injury among patients who have undergone cardiac surgery. High-quality randomized controlled trials are warranted to further examine the cardioprotective effects of TXA.

Hemostatic Abnormalities in Gaucher Disease: Mechanisms and Clinical Implications

Gaucher disease (GD) is a rare inherited lysosomal metabolism disorder, characterized by an accumulation into lysosomes of reticuloendothelial cells, especially in the bone marrow, spleen, and liver of β-glucosylceramide and glucosyl sphingosine, which is its deacylated product. Impaired storage is responsible for a chronic inflammatory state at the sites of accumulation and together represents the pathophysiological cause of GD. GD is a progressive, multi-organ chronic disorder. Type 1 GD is the most prevalent form, with heterogeneous multisystem involvement and different severity of symptoms at any age. Hematological involvement is consistent, and a bleeding tendency is frequent, particularly at diagnosis. Several coagulation and primary hemostasis abnormalities are observed in GD. Bleeding manifestations are rarely severe and usually mucocutaneous. Post-operative, delivery, and post-partum hemorrhages are also common. Thrombocytopenia, platelet function defects, and clotting abnormalities, alone or variably associated, contribute to increase the risk of bleeding in GD. Enzyme replacement therapy (ERT) or substrate reduction therapy (SRT) are the two specific available treatments effective in improving typical hematological symptoms and abnormalities, including those of hemostasis. However, the use of medication to potentiate hemostasis may be also useful in defined clinical situations: recent starting of ERT/SRT, surgery, delivery, and life-threatening bleeding.

A randomized control trial on the role of tranexamic acid in preventing intraoperative bleeding during external dacryocystorhinostomy

Purpose

To evaluate the role of tranexamic acid in controlling intra-operative and immediate post-operative bleeding during external dacryocystorhinostomy.

Methods

This was a double-blinded randomized placebo-controlled trial. All patients diagnosed with primary acquired nasolacrimal duct obstruction presenting between June 2018 to December 2019 were included in the study. All patients in the study group received a single dose of 1 gm tranexamic acid injection intravenously 30 minutes before the surgery, whereas the patients from group B (placebo) received normal saline. The effect of the injection was measured in terms of duration of the surgery, surgical field grading, amount of total blood loss during the surgery, and the need for postoperative nasal packing.

Results

A total of 96 patients were included, of whom 45 were males and 51 were females. The study group (Group A) included 51 patients (27 males and 24 females) and the control group (Group B) included 45 patients (18 males and 27 females). There were no statistically significant differences between the two groups in terms of the duration of surgery (48.43 ± 20.01 minutes vs. 53.38 ± 19.8 minutes, P = 0.228), view of the surgical field (P = 0.084), the amount of intraoperative blood loss (88.63 ± 69.34 mL vs. 88.89 ± 51.93 mL, P = 0.984) and requirement of postoperative nasal packing (54.9% vs 62.2%, P = 0.471).

Conclusion

There seems to be little to justify the role of preoperative intravenous tranexamic acid injection in controlling intra-operative and immediate postoperative bleeding during external dacryocystorhinostomy.

Update on Applications and Limitations of Perioperative Tranexamic Acid

Tranexamic acid (TXA) is a potent antifibrinolytic with documented efficacy in reducing blood loss and allogeneic red blood cell transfusion in several clinical settings. With a growing emphasis on patient blood management, TXA has become an integral aspect of perioperative blood conservation strategies. While clinical applications of TXA in the perioperative period are expanding, routine use in select clinical scenarios should be supported by evidence for efficacy. Furthermore, questions regarding optimal dosing without increased risk of adverse events such as thrombosis or seizures should be answered. Therefore, ongoing investigations into TXA utilization in cardiac surgery, obstetrics, acute trauma, orthopedic surgery, neurosurgery, pediatric surgery, and other perioperative settings continue. The aim of this review is to provide an update on the current applications and limitations of TXA use in the perioperative period.