Tranexamic acid as a therapeutic option for melasma management: meta-analysis and systematic review of randomized controlled trials.

Purpose: This study aimed to evaluate the efficacy of tranexamic acid (TXA) in treating melasma through a meta-analysis and systematic review of randomized controlled trials (RCTs). The study focused on identifying associated adverse effects and comparing TXA's effectiveness with other melasma treatments.Materials and methods: Following PROSPERO and PRISMA guidelines, an extensive electronic search was conducted across four databases for RCTs on TXA use in melasma. Inclusion criteria encompassed full-text English articles with specific outcome measures, while studies with high bias risk or non-English publications were excluded. Data were extracted from 22 relevant studies and analyzed using the RevMan software, with heterogeneity identified using I² statistics and forest plots.Results: A total of 22 studies with 1280 patients were included. TXA was administered orally, topically, or via injection, with treatment durations ranging from 8 weeks to nearly 2 years. TXA significantly reduced melasma severity, evidenced by reductions in MASI, mMASI, MI, and hemi-MASI scores. Oral TXA showed the most substantial decrease in MASI scores, followed by injections and topical applications. However, studies exhibited high heterogeneity, particularly in combined treatments. Adverse effects included gastrointestinal discomfort, skin irritation, and menstrual irregularities.Conclusions: TXA is effective in treating melasma, either alone or combined with other treatments. Despite significant reductions in melasma severity, further research is necessary to standardize TXA administration methods and address long-term effects. The high heterogeneity observed suggests a need for more consistent treatment protocols.

The hemostatic and anti-inflammatory effects of intravenous single-dose of tranexamic acid in double-segment posterior lumbar interbody fusion: a case control study.

This study aims to observe the hemostatic and anti-inflammatory effects of intravenous administration of tranexamic acid (TXA) in dual segment posterior lumbar interbody fusion (PLIF). The data of 53 patients with lumbar disease treated with double-segment PLIF were included in this study. The observation group was received a single-dose intravenous of TXA (1 g/100 mL) 15 min before skin incision after general anesthesia. The control group was not received TXA. The observation indicators included postoperative activated partial prothrombin time (APTT), thrombin time (PT), thrombin time (TT), fibrinogen (FIB), platelets (PLT), and postoperative deep vein thrombosis in the lower limbs, surgical time, intraoperative bleeding volume, postoperative drainage volume, transfusion rate, postoperative hospital stay, red blood cell (RBC), hemoglobin (HB), hematocrit (HCT), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) on the 1st, 4th, 7th, and last tested day after surgery. All patients successfully completed the operation, and there was no deep vein thrombosis after operation. There was no statistically significant difference in postoperative APTT, PT, TT, FIB, PLT, surgical time, and postoperative hospital stay between the two groups (p > 0.05). The intraoperative bleeding volume, postoperative drainage volume, and transfusion rate in the observation group were lower than those in the control group, and the differences were statistically significant (p < 0.05). There was no statistically significant difference in RBC, HB, HCT, CRP, and ESR between the two groups on the 1st, 4th, 7th, and last tested day after surgery (p > 0.05). Intravenous administration of TXA in dual segment PLIF does not affect coagulation function and can reduce bleeding volume, postoperative drainage volume, and transfusion rate. Moreover, it does not affect the postoperative inflammatory response.

Hospital policy of tranexamic acid to reduce transfusion in major non-cardiac surgery (TRACTION): protocol for a phase IV randomised controlled trial.

INTRODUCTION: Tranexamic acid (TXA) is an inexpensive and widely available medication that reduces blood loss and red blood cell (RBC) transfusion in cardiac and orthopaedic surgeries. While the use of TXA in these surgeries is routine, its efficacy and safety in other surgeries, including oncologic surgeries, with comparable rates of transfusion are uncertain. Our primary objective is to evaluate whether a hospital-level policy implementation of routine TXA use in patients undergoing major non-cardiac surgery reduces RBC transfusion without increasing thrombotic risk. METHODS AND ANALYSIS: A pragmatic, registry-based, blinded, cluster-crossover randomised controlled trial at 10 Canadian sites, enrolling patients undergoing non-cardiac surgeries at high risk for RBC transfusion. Sites are randomised in 4-week intervals to a hospital policy of intraoperative TXA or matching placebo. TXA is administered as 1 g at skin incision, followed by an additional 1 g prior to skin closure. Coprimary outcomes are (1) effectiveness, evaluated as the proportion of patients transfused RBCs during hospital admission and (2) safety, evaluated as the proportion of patients diagnosed with venous thromboembolism within 90 days. Secondary outcomes include: (1) transfusion: number of RBC units transfused (both at a hospital and patient level); (2) safety: in-hospital diagnoses of myocardial infarction, stroke, deep vein thrombosis or pulmonary embolism; (3) clinical: hospital length of stay, intensive care unit admission, hospital survival, 90-day survival and the number of days alive and out of hospital to day 30; and (4) compliance: the proportion of enrolled patients who receive a minimum of one dose of the study intervention. ETHICS AND DISSEMINATION: Institutional research ethics board approval has been obtained at all sites. At the completion of the trial, a plain language summary of the results will be posted on the trial website and distributed in the lay press. Our trial results will be published in a peer-reviewed scientific journal. TRIAL REGISTRATION NUMBER: NCT04803747.

Effect of Intense Pulsed Light versus Intradermal Tranexamic Acid for the Management of Melasma.

OBJECTIVE: To compare the effectiveness of intense pulsed light (IPL) and intradermal tranexamic acid (TXA) in treating melasma. STUDY DESIGN: A cross-sectional analytical study. Place and Duration of the Study: Department of Dermatology, Dow International Medical College, Dow University Hospital, Karachi, Pakistan, from 15th January to 15th July 2023. METHODOLOGY: A total of 62 patients with melasma, aged 20-50 years, were divided into two groups. Group A (32 patients) received IPL (560 nm filter was used) treatment, and Group B (30 patients) received intradermal TXA. Each group underwent four treatment sessions with varying intervals. Melasma area and severity index (MASI) scores were used to compare the effects of treatment. RESULTS: After a 3-month treatment period, both groups showed reduced mMASI scores compared to baseline with a significant initial difference between Group A (8.6 ± 4.2) and Group B (5.4 ± 2.7, p <0.001). However, post-treatment, there was no significant difference in mMASI scores (Group A: 3.8 ± 2.6; Group B: 3.2 ± 2.0, p = 0.29). IPL treatment (Group A) demonstrated a significant reduction in mMASI scores (57.1 ± 19.7) compared to intradermal TXA treatment (Group B, 42.2 ± 18.8, p = 0.0034). CONCLUSION: Both IPL and intradermal TXA treatments effectively reduced melasma, with IPL exhibiting superior results. However, post-treatment outcomes converged, emphasising the need for personalised approaches considering the unique characteristics of South East Asian skin. KEY WORDS: Intense pulsed light, Melasma, Intradermal tranexamic acid.

Bleeding Reversal With Antifibrinolytics or Cryoprecipitate Following Thrombolysis for Acute Ischemic Stroke: A Case Series.

Patients who develop an intracerebral hemorrhage (ICH) following thrombolysis in acute ischemic stroke (AIS) have a mortality rate as high as 50%. Treatment options include blood products, such as cryoprecipitate, or antifibrinolytics, such as tranexamic acid (TXA) or ε-aminocaproic acid (EACA). Current guidelines recommend cryoprecipitate first-line despite limited data to support one agent over another. In addition, compared to antifibrinolytics, cryoprecipitate is higher in cost and requires thawing before use. This case series seeks to characterize the management of thrombolytic reversal at a single institution as well as provide additional evidence for antifibrinolytics in this setting. Patients were included for a retrospective review if they met the following criteria: presented between January 2011-January 2017, were >18 years of age, were admitted for AIS, received a thrombolytic, and received TXA EACA, or cryoprecipitate. Twelve patients met the inclusion criteria. Ten (83.3%) developed an ICH, one (8.3%) experienced gastrointestinal bleeding, and one (8.3%) had bleeding at the site of knee arthroscopy. Eleven patients received cryoprecipitate (median dose: 10 units), three received TXA (median dose: 1,000 mg), and one patient received EACA (13 g). TXA was administered faster than the first blood product at a mean time of 19 min and 137 min, respectively. Hemorrhagic expansion (N = 8, 66.67%) and inhospital mortality (N = 7, 58.3%) were high. While limited by its small sample size, this case series demonstrates significant variability in reversal strategies for thrombolysis-associated bleeding. It also provides additional evidence for the role of antifibrinolytics in this setting.

The effect of preoperative use of anticoagulants on the hemostatic effect of intravenous application of tranexamic acid in PLIF: a case control study.

Intravenous application of tranexamic acid (TXA) in posterior lumbar interbody fusion (PLIF) can effectively reduce blood loss without affecting coagulation function. However, it has not been reported whether preoperative use of anticoagulants may affect the efficacy of TXA in PLIF. The purpose of this study is to observe the effect of preoperative use of anticoagulants on coagulation indicators and blood loss after PLIF receiving intravenous unit dose TXA. A retrospective analysis was conducted on data from 53 patients with PLIF between 2020.11 and 2022.9, who received intravenous application of a unit dose of TXA (1 g/100 mL) 15 min before the skin incision after general anesthesia. Those who used anticoagulants within one week before surgery were recorded as the observation group, while those who did not use anticoagulants were recorded as the control group. The main observation indicators include surgical time, intraoperative blood loss, postoperative drainage volume, blood transfusion, and red blood cell (RBC), hemoglobin (HB), and hematocrit (HCT) measured on the 1st, 4th, 7th, and last-test postoperative days. Secondary observation indicators included postoperative incision healing, deep vein thrombosis of lower limbs, postoperative hospital stay, and activated partial thrombin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen (FIB), and platelets (PLT) on the 1st and 4th days after surgery. The operation was successfully completed in both groups, the incision healed well after operation, and no lower limb deep vein thrombosis occurred. There was no significant difference in surgical time, intraoperative blood loss, postoperative drainage volume, and blood transfusion between the two groups (p > 0.05). There was no significant difference in the RBC, HB, and HCT measured on the 1st, 4th, 7th, and last-test postoperative days between the two groups (p > 0.05). There was no statistically significant difference in APTT, PT, TT, FIB and PLT between the two groups on the 1st and 4th postoperative days (p > 0.05). There was no significant difference in postoperative hospital stay between the two groups (p > 0.05). The use of anticoagulants within one week before surgery does not affect the hemostatic effect of intravenous unit dose TXA in PLIF.

Ultra-Early and Short-Term Tranexamic Acid Treatment in Patients With Good- and Poor-Grade Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND AND OBJECTIVES: The results of the ULTRA trial showed that ultra-early and short-term treatment with tranexamic acid (TXA) does not improve clinical outcome after aneurysmal subarachnoid hemorrhage (aSAH). Possibly, the lack of a beneficial effect in all patients with aSAH is masked by antagonistic effects of TXA in certain subgroups. In this post hoc subgroup analysis, we investigated the effect of TXA on clinical outcome in patients with good-grade and poor-grade aSAH. METHODS: The ULTRA trial was a multicenter, prospective, randomized, controlled, open-label trial with blinded outcome assessment. Participants received ultra-early and short-term TXA in addition to usual care or usual care only. This post hoc subgroup analysis included only ULTRA participants with confirmed aSAH and available World Federation of Neurosurgical Societies (WFNS) grade on admission. Patients were categorized into those with good-grade (WFNS 1-3) and poor-grade (WFNS 4-5) aSAH. The primary outcome was clinical outcome assessed by the modified Rankin scale (mRS). Odds ratios (ORs) and adjusted ORs (aORs) with 95% CIs were calculated using ordinal regression analyses. Analyses were performed using the as-treated principle. In all patients with aSAH, no significant effect modification of TXA on clinical outcome was observed for admission WFNS grade (p = 0.10). RESULTS: Of the 812 ULTRA participants, 473 patients had (58%; N = 232 TXA, N = 241 usual care) good-grade and 339 (42%; N = 162 TXA, N = 176 usual care) patients had poor-grade aSAH. In patients with good-grade aSAH, the TXA group had worse clinical outcomes (OR: 0.67, 95% CI 0.48-0.94, aOR 0.68, 95% CI 0.48-0.94) compared with the usual care group. In patients with poor-grade aSAH, clinical outcomes were comparable between treatment groups (OR: 1.04, 95% CI 0.70-1.55, aOR 1.05, 95% CI 0.70-1.56). DISCUSSION: This post hoc subgroup analysis provides another important argument against the use of TXA treatment in patients with aSAH, by showing worse clinical outcomes in patients with good-grade aSAH treated with TXA and no clinical benefit of TXA in patients with poor-grade aSAH, compared with patients treated with usual care. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov (NCT02684812; submission date February 18, 2016, first patient enrollment on July 24, 2013). CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that tranexamic acid, given for <24 hours within the first 24 hours, does not improve the 6-month outcome in good-grade or poor initial-grade aneurysmal SAH.

Efficacy and safety of intravenous tranexamic acid in microscopic modified radical mastoidectomy: a study protocol for a prospective, randomised, double-blind controlled trial.

INTRODUCTION: Radical mastoidectomy is a common procedure for chronic suppurative otitis media, typically performed under a microscope. The smooth operation is closely related to the clarity of the operative field. Our trial is designed to investigate whether the intravenous administration of tranexamic acid (TXA) can improve the clarity of the operative field, reduce the operative time, and increase surgeon satisfaction. METHODS AND ANALYSIS: This study is a prospective, randomised, double-blinded, controlled trial that aims to investigate the effects of TXA on patients with otitis media. The trial will include patients between the ages of 18 and 65 who will be randomly assigned to either the TXA group or the control group. In the TXA group, patients will receive 1 g of TXA diluted to 20 mL of normal saline before anaesthesia induction while the control group will receive 20 mL of normal saline. The primary outcome measure will be the Modena Bleeding Score, which will assess the clarity of the surgical field. Secondary outcomes will include the surgeon's satisfaction with surgical conditions, operation time, laboratory measurements (prothrombin time, activated partial thromboplastin time, fibrin degradation products, D-dimer) and levels of inflammatory factors (such as IL-6) at 24 hours postoperatively. In addition, the incidence of general adverse reactions such as postoperative nausea, vomiting and dizziness; serious adverse events such as arterial and venous thromboembolism, myocardial infarction and epilepsy within 90 days will be compared between the two groups. ETHICS AND DISSEMINATION: The protocol was approved by the Ethics Committee of Peking University People's Hospital (2021PHB173-001), on 19 July 2021. The trial results will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ChiCTR2100049183.

Peroperative administration of tranexamic acid in Roux-en-Y and one-anastomosis gastric bypass to reduce haemorrhage in patients with morbid obesity: protocol for randomised controlled trial (PATRY trial).

INTRODUCTION: By implementation of Enhanced Recovery After Bariatric Surgery protocols and day-care surgery, early discharge poses a challenge if excessive bleeding occurs after bariatric surgery. Tranexamic acid (TXA) has demonstrated efficacy in other surgical fields and in bariatric pilot studies. This trial aims to assess the efficacy of peroperative administration of TXA in reducing haemorrhage in patients undergoing gastric bypass surgery. METHOD AND ANALYSIS: This is a multicentre, phase III, double-blind randomised controlled trial in six high-volume bariatric centres in the Netherlands. A total of 1524 eligible patients, aged 18 years or older, undergoing primary gastric bypass surgery (either Roux-en-Y gastric bypass or one-anastomosis gastric bypass) will be randomised between TXA and placebo (1:1, variable block, stratified for centre, day-care/overnight stay and type of surgery) after obtaining informed consent (2.5% less haemorrhage, power 80%, 2-sided-α 0.05 and 10% dropout). Exclusion criteria are pregnancy, amedical history of acute bleeding (without cause), venous thrombotic events (VTEs), epilepsy, anticoagulant use and iatrogenic bleeding during surgery (aside from staple line). The primary outcome is postoperative haemorrhage requiring intervention within 30 days postoperatively. Secondary outcome measures are staple line reinforcement, blood loss, duration of surgery, postoperative haemoglobin, vital parameters, minor and major complications, side effects of TXA (nausea, hypotension and VTE), length of hospital stay and directly made costs. ETHICS AND DISSEMINATION: Written informed consent will be obtained from all participants. The protocol has been approved by the Medical Research Ethics Committees United, Nieuwegein, on 7 February 2023 (registration number: R22.102). Results will be disseminated through peer-reviewed publications and conferences. TRIAL REGISTRATION NUMBER: NCT05464394.

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.

Incidence of deep venous thrombosis in patients with hemophilia undergoing bilateral simultaneous total knee arthroplasty: a retrospective cohort study.

BACKGROUND: Hemophilic arthropathy usually affects the knees bilaterally. In order to reduce costs and improve rehabilitation, bilateral simultaneous total knee arthroplasty (TKA) can be performed. However, pharmacological prophylaxis for deep venous thrombosis (DVT) remains controversial in patients with severe hemophilia. The purpose of this study was to establish the incidence of DVT in severe hemophilia A patients undergoing bilateral simultaneous TKA without pharmacological thromboprophylaxis. METHODS: Consecutive patients with severe hemophilia A undergoing bilateral simultaneous TKA at a single center between January 2015 and December 2020 were retrospectively reviewed. All patients received a modified coagulation factor substitution regimen. Tranexamic acid (TXA) was used for hemostasis in all patients during surgery. All patients followed a standardized postoperative protocol with routine mechanical thromboprophylaxis, and none received anticoagulation. D-dimer was measured preoperatively, on the day of the operation and on postoperative days 1, 7 and 14. Ultrasound (US) of the lower extremities was performed before (within 3 days of hospitalization) and after surgery (days 3 and 14) to detect asymptomatic DVT. Patients were followed up until 2 years after surgery for the development of symptomatic DVT or pulmonary embolism (PE). RESULTS: 38 male patients with severe hemophilia A underwent 76 simultaneous TKAs. Mean (± standard deviation) age at the time of operation was 41.7 (± 17.1) years. Overall, 47.3% of patients had D-dimer concentrations above the threshold 10 µg/mL on day 7 and 39.5% on day 14. However, none of the patients had DVT detected on postoperative US, nor developed symptomatic DVT or PE during the 2-year follow-up. CONCLUSIONS: The risk of DVT in patients with severe hemophilia A after bilateral simultaneous TKA is relatively low, and routine pharmacological thromboprophylaxis may not be needed.

Tranexamic acid versus placebo in individuals with intracerebral haemorrhage treated within 2 h of symptom onset (STOP-MSU): an international, double-blind, randomised, phase 2 trial.

BACKGROUND: Tranexamic acid, an antifibrinolytic agent, might attenuate haematoma growth after an intracerebral haemorrhage. We aimed to determine whether treatment with intravenous tranexamic acid within 2 h of an intracerebral haemorrhage would reduce haematoma growth compared with placebo. METHODS: STOP-MSU was an investigator-led, double-blind, randomised, phase 2 trial conducted at 24 hospitals and one mobile stroke unit in Australia, Finland, New Zealand, Taiwan, and Viet Nam. Eligible participants had acute spontaneous intracerebral haemorrhage confirmed on non-contrast CT, were aged 18 years or older, and could be treated with the investigational product within 2 h of stroke onset. Using randomly permuted blocks (block size of 4) and a concealed pre-randomised assignment procedure, participants were randomly assigned (1:1) to receive intravenous tranexamic acid (1 g over 10 min followed by 1 g over 8 h) or placebo (saline; matched dosing regimen) commencing within 2 h of symptom onset. Participants, investigators, and treating teams were masked to group assignment. The primary outcome was haematoma growth, defined as either at least 33% relative growth or at least 6 mL absolute growth on CT at 24 h (target range 18-30 h) from the baseline CT. The analysis was conducted within the estimand framework with primary analyses adhering to the intention-to-treat principle. The primary endpoint and secondary safety endpoints (mortality at days 7 and 90 and major thromboembolic events at day 90) were assessed in all participants randomly assigned to treatment groups who did not withdraw consent to use any data. This study was registered with ClinicalTrials.gov, NCT03385928, and the trial is now complete. FINDINGS: Between March 19, 2018, and Feb 27, 2023, 202 participants were recruited, of whom one withdrew consent for any data use. The remaining 201 participants were randomly assigned to either placebo (n=98) or tranexamic acid (n=103; intention-to-treat population). Median age was 66 years (IQR 55-77), and 82 (41%) were female and 119 (59%) were male; no data on race or ethnicity were collected. CT scans at baseline or follow-up were missing or of inadequate quality in three participants (one in the placebo group and two in the tranexamic acid group), and were considered missing at random. Haematoma growth occurred in 37 (38%) of 97 assessable participants in the placebo group and 43 (43%) of 101 assessable participants in the tranexamic acid group (adjusted odds ratio [aOR] 1·31 [95% CI 0·72 to 2·40], p=0·37). Major thromboembolic events occurred in one (1%) of 98 participants in the placebo group and three (3%) of 103 in the tranexamic acid group (risk difference 0·02 [95% CI -0·02 to 0·06]). By 7 days, eight (8%) participants in the placebo group and eight (8%) in the tranexamic acid group had died (aOR 1·08 [95% CI 0·35 to 3·35]) and by 90 days, 15 (15%) participants in the placebo group and 19 (18%) in the tranexamic acid group had died (aOR 1·61 [95% CI 0·65 to 3·98]). INTERPRETATION: Intravenous tranexamic acid did not reduce haematoma growth when administered within 2 h of intracerebral haemorrhage symptom onset. There were no observed effects on other imaging endpoints, functional outcome, or safety. Based on our results, tranexamic acid should not be used routinely in primary intracerebral haemorrhage, although results of ongoing phase 3 trials will add further context to these findings. FUNDING: Australian Government Medical Research Future Fund.

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.

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.

Efficacy and safety of tranexamic acid in patients undergoing thoracic surgery: a systematic review and PRISMA-compliant meta-analysis

OBJECTIVES: Perioperative bleeding poses a significant issue during thoracic surgery. Tranexamic acid (TXA) is one of the most commonly used antifibrinolytic agents for surgical patients. The purpose of the current study was designed to investigate the efficacy and safety of TXA in patients undergoing thoracic surgery. METHODS: An extensive search of PubMed, Web of Science (WOS), Cochrane Library (trials), Embase, OVID, China National Knowledge Infrastructure (CNKI), Wanfang, and VIP electronic databases was performed to identify studies published between the inception of these databases and March 2023. The primary outcomes included perioperative blood loss and blood transfusions. Secondary outcomes of interest included the length of stay (LOS) in hospital and the incidence of thromboembolic events. Weighted mean differences (WMDs) or odds ratios (OR) with 95% confidence intervals (CI) were used to determine treatment effects for continuous and dichotomous variables, respectively. RESULTS: Five qualified studies including 307 thoracic surgical patients were included in the current study. Among them, 65 patients were randomly allocated to the group receiving TXA administration (the TXA group); the other 142 patients were assigned to the group not receiving TXA administration (the control group). TXA significantly reduced the quantity of hemorrhage in the postoperative period (postoperative 12h: WMD = -81.90 ml; 95% CI: -139.55 to -24.26; P = 0.005; postoperative 24h: WMD = -97.44 ml; 95% CI: -121.44 to -73.44; P< 0.00001); The intraoperative blood transfusion volume (WMD = -0.54 units; 95% CI: -1.06 to -0.03; P = 0.04); LOS in hospital (WMD = -0.6 days; 95% CI: -1.04 to -0.16; P = 0.008); And there was no postoperative thromboembolic event reported in the included studies. CONCLUSIONS: The present study demonstrated that TXA significantly decreased blood loss within 12 and 24 hours postoperatively. A qualitative review did not identify elevated risks of safety outcomes such as thromboembolic events. It also suggested that TXA administration was associated with shorter LOS in hospital as compared to control. To validate this further, additional well-planned and adequately powered randomized studies are necessary.