Comparison of Two Doses of Tranexamic Acid in Adults Undergoing Cardiac Surgery with Cardiopulmonary Bypass

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

BACKGROUND

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

STUDY DESIGN AND METHODS

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

RESULTS

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

DISCUSSION

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

Synthesis, Characterization and Evaluation of the Antimicrobial and Herbicidal Activities of Some Transition Metal Ions Complexes with the Tranexamic Acid

New tranexamic acid (TXA) complexes of ferric(III), cobalt(II), nickel(II), copper(II) and zirconium(IV) were synthesized and characterized by elemental analysis (CHN), conductimetric (Λ), magnetic susceptibility investigations (μeff), Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H-NMR), ultraviolet visible (UV-vis.), optical band gap energy (Eg) and thermal studies (TG/DTG and DTA). TXA complexes were established in 1 : 2 (metal: ligand) stoichiometric ratio according to CHN data. Based on FT-IR and 1H-NMR data the disappeared of the carboxylic proton supported the deprotonating of TXA and linked to metal ions via the carboxylate group's oxygen atom as a bidentate ligand. UV-visible spectra and magnetic moment demonstrated that all chelates have geometric octahedral structures. Eg values indicated that our complexes are more electro conductive. DTA revealed presence of water molecules in inner and outer spheres of the complexes. DTA results showed that endothermic and exothermic peaks were identified in the degradation mechanisms. The ligand and metal complexes were investigated for their antimicrobial and herbicidal efficacy. The Co(II) and Ni(II) complexes showed antimicrobial activity against some tested species. The obtained results showed a promising herbicidal effect of TXA ligand and its metal complexes particularly copper and zirconium against the three tested plants.

Effectiveness and safeties of hemocoagulase and tranexamic acid to reduce perioperative blood loss in intertrochanteric fracture PFNA fixation

This study evaluated the efficacy of hemocoagulase and tranexamic acid (TXA) in minimizing perioperative blood loss in perioperative period of proximal femoral nail antirotation (PFNA) repair. 99 patients having intertrochanteric fracture PFNA fixation were randomly assigned to the hemocoagulase, TXA, and control groups (n=33 per group). In the hemocoagulase group, 1 KU of hemocoagulase was injected preoperatively and postoperatively local sprayed, respectively; in the TXA group, 0.5g TXA was injected preoperatively and postoperatively local sprayed, respectively; and in the control group, 100 mL of physiological saline was injected before surgery and was used by postoperative local spraying, respectively. The hemocoagulase and TXA groups exhibited significant differences in preoperative hemoglobin (HB) and hematocrit (HCT) levels on postoperative days 1 and 3, intraoperative bleeding, 24-hour postoperative drainage, total perioperative bleeding, transfusion rate, and postoperative hospitalization duration compared to the control group. Furthermore, the hemocoagulase and TXA groups showed significant differences in postoperative day 3 HB and HCT levels and postoperative hospitalization duration compared to each other. In conclusions, the combined use of systemic preoperative and local postoperative hemocoagulase and TXA spraying is found to significantly decrease perioperative blood loss in intertrochanteric fracture patients undergoing PFNA. Hemocoagulase is observed to have a superior effect compared to TXA.

Is High-Dose Tranexamic Safe in Spine Surgery? A Systematic Review and Meta-Analysis

STUDY DESIGN

Literature review and meta-analysis.

OBJECTIVES

Single-center series may be underpowered to detect whether high-dose (HD) tranexamic acid (TXA) confers a higher risk of complications. We sought to determine the safety and efficacy of HD TXA as compared to low-dose (LD) or placebo.

METHODS

A systematic literature review was performed to find studies where spine surgery patients were given HD TXA (loading dose ≥30 mg/kg). Complication rates were pooled, and meta-analyses performed on outcomes of interest. Articles were evaluated for risk of bias and a strength of evidence assessment was given for each conclusion.

RESULTS

Twenty three studies (n = 2331) were included. The pooled medical complication rate was 3.2% in pediatric patients, 8.2% in adults. Using lower dose TXA or placebo as the reference, meta-analysis showed no difference in medical complications (n = 1,723, OR 1.22 [95% CI, .78 to 1.22]; P = .388; I2 = 0%) or thrombotic events (n = 1158 patients, OR 1.27 [95% CI, .71 to 2.63]; P = .528; I2 = 0%). Compared to LD, HD TXA was associated with less intraoperative blood loss (823 patients, WMD = -285 [95% CI, -564 to -5.90]; P = .0454; I2 = 86%), fewer perioperative transfusions (n = 505, OR .28 [95% CI, .082 to .96]; P = .043; I2 = 76%) and lower perioperative transfusion volumes (n = 434, WMD -227.7 mL [95% CI, -377.3 to -78.02]; P = .0029; I2 = 0%).

CONCLUSION

Compared to LD TXA or placebo, there is moderate evidence that HD is not associated with an increased risk of medical complications. Compared to LD, there is moderate evidence that HD reduces transfusion requirements. High-Dose TXA can be safely utilized in healthy patients undergoing major spine surgery.

Tranexamic Acid in Non-Traumatic Intracerebral Haemorrhage (TANICH II): Introducing the Potential Role of 3 g Tranexamic Acid in Haematoma Reduction

Background

Intracerebral haemorrhage (ICH) can be devastating, particularly if haematoma expansion occurs. The efficacy of tranexamic acid (TXA), an anti-fibrinolytic agent, in reducing haematoma expansion is now being studied worldwide. However, the optimal dosage of TXA has yet to be determined. This study was designed to further establish the potential of different doses of TXA.

Methods

A double-blinded, randomised, placebo-controlled study was carried out among adults with non-traumatic ICH. Eligible study subjects were randomly assigned to receive placebo, 2-g TXA treatment or 3-g TXA treatment. Haematoma volumes before and after intervention were measured using the planimetric method.

Results

A total of 60 subjects with 20 subjects in each treatment group were recruited for this study. Among the 60 subjects, the majority were male (n = 36, 60%), had known cases of hypertension (n = 43, 71.7%) and presented with full Glasgow coma scale (GCS) (n = 41, 68.3%). The results showed that there was no statistically significant difference (P = 0.315) in the mean changes of haematoma volume when compared with three study groups using ANCOVA, although the 3-g TXA group was the only group that showed haematoma volume reduction (mean reduction of 0.2 cm³) instead of expansion as in placebo (mean expansion 1.8 cm³) and 2-g TXA (mean expansion 0.3 cm³) groups. Good recovery was observed in all study groups, with only three subjects being moderately disabled. No adverse effects were reported in any of the study groups.

Conclusion

To the best of our knowledge, this is the first clinical study using 3 g of TXA in the management of non-traumatic ICH. From our study, 3 g of TXA may potentially be helpful in reducing haematoma volume. Nonetheless, a larger-scale randomised controlled trial should be carried out to further establish the role of 3 g of TXA in non-traumatic ICH.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Efficacy of high dose tranexamic acid (TXA) for hemorrhage: A systematic review and meta-analysis

BACKGROUND

Standard dose (≤ 1 g) tranexamic acid (TXA) has established mortality benefit in trauma patients. The role of high dose IV TXA (≥2 g or ≥30 mg/kg as a single bolus) has been evaluated in the surgical setting, however, it has not been studied in trauma. We reviewed the available evidence of high dose IV TXA in any setting with the goal of informing its use in the adult trauma population.

METHODS

We searched MEDLINE, EMBASE and unpublished sources from inception until July 27, 2022 for studies that compared standard dose with high dose IV TXA in adults (≥ 16 years of age) with hemorrhage. Screening and data abstraction was done independently and in duplicate. We pooled trial data using a random effects model and considered randomized controlled trials (RCTs) and observational cohort studies separately. We assessed the individual study risk of bias using the Cochrane Risk of Bias for RCTs and the Newcastle-Ottawa Scale for observational cohort studies. The overall certainty of evidence was assessed using the GRADE approach (Grading of Recommendations Assessment, Development and Evaluation).

RESULTS

We included 20 studies with a combined total of 12,523 patients. Based on pooled RCT data, and as compared to standard dose TXA, high dose IV TXA probably decreases transfusion requirements (odds ratio [OR] 0.86, 95% confidence interval [CI] 0.76 to 0.97, moderate certainty) but with possibly no effect on blood loss (mean difference [MD] 43.31 ml less, 95% CI 135.53 to 48.90 ml less, low certainty), and an uncertain effect on thromboembolic events (OR 1.33, 95% CI 0.86 to 2.04, very low certainty) and mortality (OR 0.70, 95% CI 0.37 to 1.32, very low certainty).

CONCLUSION

When compared to standard dose, high dose IV TXA probably reduces transfusion requirements with an uncertain effect on thromboembolic events and mortality.

LEVEL OF EVIDENCE

Systematic review and meta-analysis, level IV.

Characteristics and Outcomes of Liver Transplantation Recipients after Tranexamic Acid Treatment and Platelet Transfusion: A Retrospective Single-Centre Experience

Background and Objectives: Patients undergoing liver transplantation (LT) often require increased blood product transfusion due to pre-existing coagulopathy and intraoperative fibrinolysis. Strategies to minimise intraoperative bleeding and subsequent blood product requirements include platelet transfusion and tranexamic acid (TXA). Prophylactic TXA administration has been shown to reduce bleeding and blood product requirements intraoperatively. However, its clinical use is still debated. The aim of this study was to report on a single-centre practice and analyse clinical characteristics and outcomes of LT recipients according to intraoperative treatment of TXA or platelet transfusion. Materials and Methods: This was a retrospective observational cohort study in which we reviewed 162 patients' records. Characteristics, intraoperative requirement of blood products, postoperative development of thrombosis and outcomes were compared between patients without or with intraoperative TXA treatment and without or with platelet transfusion. Results: Intraoperative treatment of TXA and platelets was 53% and 57.40%, respectively. Patients who required intraoperative administration of TXA or platelet transfusion also required more transfusion of blood products. Neither TXA nor platelet transfusion were associated with increased postoperative development of hepatic artery and portal vein thrombosis, 90-day mortality or graft loss. There was a significant increase in the median length of intensive care unit (ICU) stay in those who received platelet transfusion only (2.00 vs. 3.00 days; p = 0.021). Time to extubate was significantly different in both those who required TXA and platelet transfusion intraoperatively. Conclusions: Our analysis indicates that LT recipients still required copious intraoperative transfusion of blood products, despite the use of intraoperative TXA and platelets. Our findings have important implications for current transfusion practice in LT recipients and may guide clinicians to act upon these findings, which will support global efforts to encourage a wider use of TXA to reduce transfusion requirements, including platelets.

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

Background

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

Methods

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

Results

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

Conclusion

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

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

PURPOSE

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

METHODOLOGY

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

RESULTS

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

CONCLUSIONS

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

Effect of High- vs Low-Dose Tranexamic Acid Infusion on Need for Red Blood Cell Transfusion and Adverse Events in Patients Undergoing Cardiac Surgery: The OPTIMAL Randomized Clinical Trial

IMPORTANCE

Tranexamic acid is recommended for reducing blood loss and transfusion in cardiac surgery. However, it remains unknown whether a high dose of tranexamic acid provides better blood-sparing effect than a low dose without increasing the risk of thrombotic complications or seizures in cardiac surgery.

OBJECTIVE

To compare the efficacy and adverse events of high-dose vs low-dose tranexamic acid in patients undergoing cardiac surgery with cardiopulmonary bypass.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, double-blind, randomized clinical trial among adult patients undergoing cardiac surgery with cardiopulmonary bypass. The study enrolled 3079 patients at 4 hospitals in China from December 26, 2018, to April 21, 2021; final follow-up was on May 21, 2021.

INTERVENTIONS

Participants received either a high-dose tranexamic acid regimen comprising a 30-mg/kg bolus, a 16-mg/kg/h maintenance dose, and a 2-mg/kg prime (n = 1525) or a low-dose regimen comprising a 10-mg/kg bolus, a 2-mg/kg/h maintenance dose, and a 1-mg/kg prime (n = 1506).

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was the rate of allogeneic red blood cell transfusion after start of operation (superiority hypothesis), and the primary safety end point was a composite of the 30-day postoperative rate of mortality, seizure, kidney dysfunction (stage 2 or 3 Kidney Disease: Improving Global Outcomes [KDIGO] criteria), and thrombotic events (myocardial infarction, ischemic stroke, deep vein thrombosis, and pulmonary embolism) (noninferiority hypothesis with a margin of 5%). There were 15 secondary end points, including the individual components of the primary safety end point.

RESULTS

Among 3079 patients who were randomized to treatment groups (mean age, 52.8 years; 38.1% women), 3031 (98.4%) completed the trial. Allogeneic red blood cell transfusion occurred in 333 of 1525 patients (21.8%) in the high-dose group and 391 of 1506 patients (26.0%) in the low-dose group (risk difference [RD], -4.1% [1-sided 97.55% CI, -∞ to -1.1%]; relative risk, 0.84 [1-sided 97.55% CI, -∞ to 0.96; P = .004]). The composite of postoperative seizure, thrombotic events, kidney dysfunction, and death occurred in 265 patients in the high-dose group (17.6%) and 249 patients in the low-dose group (16.8%) (RD, 0.8%; 1-sided 97.55% CI, -∞ to 3.9%; P = .003 for noninferiority). Fourteen of the 15 prespecified secondary end points were not significantly different between groups, including seizure, which occurred in 15 patients (1.0%) in the high-dose group and 6 patients (0.4%) in the low-dose group (RD, 0.6%; 95% CI, -0.0% to 1.2%; P = .05).

CONCLUSIONS AND RELEVANCE

Among patients who underwent cardiac surgery with cardiopulmonary bypass, high-dose compared with low-dose tranexamic acid infusion resulted in a modest statistically significant reduction in the proportion of patients who received allogeneic red blood cell transfusion and met criteria for noninferiority with respect to a composite primary safety end point consisting of 30-day mortality, seizure, kidney dysfunction, and thrombotic events.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03782350.

Use of Tranexamic Acid in Liposculpture: A Double-Blind, Multicenter, Randomized Clinical Trial

BACKGROUND

Intraoperative hemostasis should be performed with great caution since bleeding is a huge enemy of patient safety during surgery. Tranexamic acid (TXA) is a lysine synthetic derivate that inhibits fibrinolysis and diminishes the bleeding by blocking the 5 lysine-binding sites for plasminogen.

PURPOSE

We are comparing the efficacy of tranexamic acid vs. placebo as a hemostatic agent in liposculpture procedures.

METHODS DESIGN, SETTING AND PARTICIPANTS

We conducted a multicenter, double-blinded, randomized, controlled clinical trial in patients who were scheduled for liposculpture in 3 plastic surgery centers (Colombia and Mexico) between January 2019 and February of 2020. Interventions: 141 patients were randomly assigned into three groups: Intravenous (1 gr of TXA), subcutaneous (1 gr of TXA) and placebo (Normal Saline). 47 patients were assigned to each group. 30 patients were male and 111 were female. Main outcome: Evaluate the amount of postoperative bleeding between groups. The primary outcome was measured by the hemoglobin (Hb) point loss at day 1 (Preoperative Hb minus Hb at day 1 postop) and the Hb (mg/dl) point loss at day 5 (Preoperative Hb minus Hb at day 5 postop).

RESULTS

We found the Intravenous intervention group to have a greater hemoglobin level than the other two groups on both the first postoperative day (P=0.0001) and the fifth postoperative day (P=0.001). There were no statistical differences in Hb values between the placebo and the subcutaneous intervention groups.

CONCLUSIONS

Intravenous Tranexamic acid is a good therapeutic choice to implement on liposculpture procedures to decrease postoperative bleeding.

High-Dose Tranexamic Acid in Patients Underwent Surgical Repair of Aortic Dissection Might Reduce Postoperative Blood Loss: A Cohort Analysis

Introduction

While tranexamic acid (TXA) is widely used in patients with acute type A aortic dissection (ATAAD) who undergo surgical repair to reduce blood loss and transfusion requirement, the optimal dosage of TXA is unknown in these patients.

Materials and Methods

This was a retrospective cohort study that compared high-dose (>50 mg/kg) and low-dose TXA (≤50 mg/kg) in patients with ATAAD who underwent surgical repair. Propensity score matching (PSM) was performed between the two groups and results were analyzed in matched cases. The primary outcome was postoperative blood loss within 3 days after surgery. The secondary outcomes were total blood loss after surgery and perioperative blood transfusion, and safety outcomes were also assessed.

Results

Through medical record screening, 529 patients were identified. After PSM, 196 patients in the high-dose group and 196 patients in the low-dose group were matched and included in the final analysis. Postoperative blood loss in 3 days after surgery was 940 mL (710–1,010 mL) in the low-dose group and 695 mL (620–860 mL) in the high-dose group. The difference was statistically significant (P < 0.001). Total postoperative blood loss was also statistically less in the high-dose group compared to the low-dose group (1,890 mL (1,410–2,100 mL) vs. 2,040 mL (1,460–2,320 mL), P = 0.032). No difference was found between the two groups in transfusion and safety outcomes.

Conclusion

In ATAAD patients who underwent surgical repair, high-dose TXA significantly reduced postoperative blood loss compared to low-dose TXA, while no difference in transfusion or adverse events was found.

How we manage blood product support and coagulation in the adult patient requiring extracorporeal membrane oxygenation

Use of extracorporeal membrane oxygenation (ECMO) is increasing among critically ill adults with cardiac and/or respiratory failure. Use of ECMO is associated with hemostatic alterations requiring use of anticoagulation and blood product support. There are limited guidelines to direct transfusion management in the adult patient supported with ECMO. The objective of this article is to describe (1) the role of the transfusion service in providing transfusion support and current understanding of transfusion thresholds, (2) the complexities of monitoring anticoagulation, and (3) the consideration regarding additional factor concentrates and antifibrinolytics within the context of ECMO support. The information provided should assist ECMO care teams in informing transfusion and anticoagulation practice while highlighting key areas for future research and collaboration.

Total Knee Arthroplasty: Superiority of Intra-Articular Tranexamic Acid Over Intravenous and Cell Salvage as Blood Sparing Strategy – A Retrospective Study

Purpose

Total knee arthroplasty is associated with considerable perioperative hemorrhage. The decrease in hemoglobin concentration and the need for allogenic blood transfusion are related to increased morbidity and mortality. Strategies for minimizing perioperative bleeding are used, such as tranexamic acid and cell salvage. The study aimed to compare intravenous, intra-articular tranexamic acid and cell salvage protocols regarding perioperative hemoglobin variation. Secondary outcomes included blood loss; allogenic transfusions; complications and in-hospital stay.

Patients and Methods

Patients submitted to unilateral total knee arthroplasty between January and December 2018 were retrospectively evaluated. After excluding 62 patients, 204 were subdivided into 3 groups according to the protocol used. Statistical analysis was performed with SPSS version 26.0. One-way ANOVA and Kruskal–Wallis tests were used. Considered a p-value of <0.05 for statistical significance.

Results

Variation of hemoglobin in the intra-articular tranexamic acid group was significantly lower than that of intravenous (p < 0.001) and cell salvage (p = 0.001) groups. Blood loss, variation of hematocrit, need for blood transfusion and in-hospital stay were also statistically significantly lower in the intra-articular tranexamic acid group. The only related complications were in the intravenous tranexamic acid group. No thromboembolic complications were identified which further solidifies the safety of tranexamic acid administration.

Conclusion

This data shows superiority of the intra-articular administration of tranexamic acid over the other techniques in total knee arthroplasty. We propose this protocol as an efficient, low-risk blood-sparing strategy.

Blood conservation outcomes and safety of tranexamic acid in coronary artery bypass graft surgery

BACKGROUND

The safety and blood management effects of Tranexamic acid (TXA) and its dose effects in coronary artery bypass graft (CABG) were still ambiguous. This study aimed to analyze these TXA effects.

METHODS

Overall, 42,010 patients undergoing CABG were enrolled in this retrospective cohort study. Patients were assigned to the TXA group (n = 29,536) and the no-TXA group (n = 12,474). Furthermore, the TXA group was divided into the high-dose (≥50 mg/kg) (16,488) and the low-dose (<50 mg/kg) (13,048) subgroup. Propensity score matching was performed in both groups respectively. The primary endpoint after CABG was composed of hospital death, perioperative myocardial infarction (PMI), stroke, acute kidney injury (AKI), and pulmonary embolism. The secondary endpoint included blood loss and blood transfusion after surgery.

RESULTS

TXA led to a 1.40-fold risk of PMI (p < 0.001). Patients in the TXA group had fewer re-operations for bleeding or tamponade [Odd ratio (OR) = 0.82, p = 0.044], less blood loss after surgery (p < 0.001), and a lower risk for blood transfusion exposure (OR = 0.45, p < 0.001) than those in the no-TXA group. The high-dose TXA reduced blood loss after cardiac surgery compared to the low-dose TXA (p < 0.001) with no associations with blood exposure or adverse events.

CONCLUSIONS

The use of TXA during CABG increased the risk of PMI despite better blood control after surgery. The high dose of TXA acquired better bleeding management. Meanwhile, it did not increase the risk of primary endpoint.

Tranexamic Acid in Pediatric Scoliosis Surgery: A Prospective Randomized Trial Comparing High-dose and Low-dose Tranexamic Acid in Adolescent Idiopathic Scoliosis Undergoing Posterior Spinal Fusion Surgery

STUDY DESIGN

Prospective randomized double-blinded trial.

OBJECTIVE

The objective of this study is to determine the efficacy of high-dose versus low-dose tranexamic acid (TXA) in adolescent idiopathic scoliosis (AIS) corrective surgery.

SUMMARY OF BACKGROUND DATA

Corrective surgery for AIS is associated with significant blood loss. Evidence on the optimum TXA dose to reduce bleeding in pediatric population is scarce.

METHODS

A total of 166 AIS patients aged between 10 and 21 years, of American Society of Anesthesiologists (ASA) physical status I and II, preoperative hemoglobin >10 g/dL, platelet count >150,000 cells/L and Cobb angle of >45° scheduled for elective single-stage posterior spinal fusion (PSF) surgery by two attending surgeons were included between March 2017 and November 2018. Patients were randomized into Group A (High Dose, 30 mg/kg TXA loading dose followed by 10 mg/kg/h infusion) and Group B (Low Dose, 10 mg/kg TXA loading dose followed by 1 mg/kg/h infusion). The primary outcome was total surgical blood loss between both groups. Secondary outcomes were transfusion requirement, perioperative changes in hemoglobin and coagulation profiles, adverse events, and factors that influence total blood loss.

RESULTS

The mean total surgical blood loss between the two groups was not significant (Group A: 928.8 ± 406.1 mL [range: 348-1857 mL]; Group B: 918.1 ± 406.2 mL [range: 271-2000 mL], P = 0.865). The median duration of surgery was 120 minutes. One patient in each group received allogenic blood transfusion during the perioperative period. There were no significant changes in hemoglobin and coagulation profile at pre-operation, post-operation 0 hour and 48 hours. Sex, number of vertebral levels fused, and duration of surgery were independently associated with total surgical blood loss. No adverse events were observed perioperatively.

CONCLUSION

Low-dose TXA was as efficacious as high-dose TXA in reducing blood loss and allogenic blood transfusion for AIS patients undergoing PSF surgery.Level of Evidence: 1.

Clinical use of tranexamic acid: evidences and controversies

Tranexamic acid (TXA) significantly reduces blood loss in a wide range of surgical procedures and improves survival rates in obstetric and trauma patients with severe bleeding. Although it mainly acts as a fibrinolysis inhibitor, it also has an anti-inflammatory effect, and may help attenuate the systemic inflammatory response syndrome found in some cardiac surgery patients. However, the administration of high doses of TXA has been associated with seizures and other adverse effects that increase the cost of care, and the administration of TXA to reduce perioperative bleeding needs to be standardized. Tranexamic acid is generally well tolerated, and most adverse reactions are considered mild or moderate. Severe events are rare in clinical trials, and literature reviews have shown tranexamic acid to be safe in several different surgical procedures. However, after many years of experience with TXA in various fields, such as orthopedic surgery, clinicians are now querying whether the dosage, route and interval of administration currently used and the methods used to control and analyze the antifibrinolytic mechanism of TXA are really optimal. These issues need to be evaluated and reviewed using the latest evidence to improve the safety and effectiveness of TXA in treating intracranial hemorrhage and bleeding in procedures such as liver transplantation, and cardiac, trauma and obstetric surgery.

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

OBJECTIVES

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

METHODS

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

FINDINGS

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

CONCLUSIONS

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

A Systematic Review of Tranexamic Acid in Plastic Surgery: What's New?

BACKGROUND

Blood loss associated with surgical interventions can lead to several complications. Therefore, minimizing perioperative bleeding is critical to improve overall survival. Several interventions have been found to successfully reduce surgical bleeding, including the antifibrinolytic agent. After aprotinin was withdrawn from the market in 2008, TXA remained the most commonly used medication. The safety and efficacy of TXA has been well studied in other specialties. TXA has been rarely used in plastic surgery, except in craniofacial procedures. Since the last review, the number of articles examining the use of TXA has doubled; so the aim of this systematic review is to update the readers on the current knowledge and clinical recommendations regarding the efficacy of TXA in plastic surgical procedures.

METHODS

A systematic literature search was conducted in Medline, SciELO, Cochrane, and Google Scholar to evaluate all articles that discussed the use of TXA in plastic surgery in the fields of aesthetic surgery, burn care, and reconstructive microsurgery.

RESULTS

A total of 233 publications were identified using the search criteria defined above. After examination of titles and abstracts, and exclusion of duplicates, a total of 23 articles were selected for analysis.

CONCLUSIONS

The literature shows a clear benefit of using TXA to decrease blood loss regardless of the administration route, with no risk of thrombosis events. Also, TXA elicits a potent anti-inflammatory response with a decrease in postoperative edema and ecchymosis, which improves recovery time. Further investigations are needed to standardize the optimal administration route and dosage of TXA.

Exposure-Response Relationship of Tranexamic Acid in Cardiac Surgery

BACKGROUND

It is unclear whether high-dose regimens of tranexamic acid in cardiac surgery (total dose, 80 to 100 mg/kg) confer a clinical advantage over low-dose regimens (total dose, approximately 20 mg/kg), particularly as tranexamic acid-associated seizure may be dose-related. The authors' aim was to characterize the exposure-response relationship of this drug.

METHODS

Databases were searched for randomized controlled trials of intravenous tranexamic acid in adult patients undergoing cardiopulmonary bypass surgery. Observational studies were added for seizure assessment. Tranexamic acid concentrations were predicted in each arm of each study using a population pharmacokinetic model. The exposure-response relationship was evaluated by performing a model-based meta-analysis using nonlinear mixed-effect models.

RESULTS

Sixty-four randomized controlled trials and 18 observational studies (49,817 patients) were included. Seventy-three different regimens of tranexamic acid were identified, with the total dose administered ranging from 5.5 mg/kg to 20 g. The maximum effect of tranexamic acid for postoperative blood loss reduction was 40% (95% credible interval, 34 to 47%), and the EC50 was 5.6 mg/l (95% credible interval, 0.7 to 11 mg/l). Exposure values with low-dose regimens approached the 80% effective concentration, whereas with high-dose regimens, they exceeded the 90% effective concentration. The predicted cumulative blood loss up to 48 h postsurgery differed by 58 ml between the two regimens, and the absolute difference in erythrocyte transfusion rate was 2%. Compared to no tranexamic acid, low-dose and high-dose regimens increased the risk of seizure by 1.2-fold and 2-fold, respectively. However, the absolute risk increase was only clinically meaningful in the context of prolonged open-chamber surgery.

CONCLUSIONS

In cardiopulmonary bypass surgery, low-dose tranexamic acid seems to be an appropriate regimen for reducing bleeding outcomes. This meta-analysis has to be interpreted with caution because the results are observational and dependent on the lack of bias of the predicted tranexamic acid exposures and the quality of the included studies.

EDITOR’S PERSPECTIVE

Comparison of the in-vivo effect of two tranexamic acid doses on fibrinolysis parameters in adults undergoing valvular cardiac surgery with cardiopulmonary bypass - a pilot investigation

Background

The blood saving efficacy of TXA in cardiac surgery has been proved in several studies, but TXA dosing regimens were varied in those studies. Therefore, we performed this study to investigate if there is a dose dependent in-vivo effect of TXA on fibrinolysis parameters by measurement of fibrinolysis markers in adults undergoing cardiac surgery with CPB.

Methods

A double-blind, randomized, controlled prospective trial was conducted from February 11, 2017 to May 05, 2017. Thirty patients undergoing cardiac valve surgery were identified and randomly divided into a placebo group, low-dose group and high-dose group by 1: 1: 1. Fibrinolysis parameters were measured by plasma levels of D-Dimers, plasminogen activator inhibitor-1 (PAI-1), thrombin activatable fibrinolysis inhibitor (TAFI), plasmin-antiplasmin complex (PAP), tissue plasminogen activator (tPA) and thrombomodulin (TM). Those proteins were measured at five different sample times: preoperatively before the TXA injection (T₁), 5 min after the TXA bolus (T₂), 5 min after the initiation of CPB (T₃), 5 min before the end of CPB (T₄) and 5 min after the protamine administration (T₅). A Thrombelastography (TEG) and standard coagulation test were also performed.

Results

Compared with the control group, the level of the D-Dimers decreased in the low-dose and high-dose groups when the patients arrived at the ICU and on the first postoperative morning. Over time, the concentrations of PAI-1, TAFI, and TM, but not PAP and tPA, showed significant differences between the three groups (P <  0.05). Compared with the placebo group, the plasma concentrations of PAI-1 and TAFI decreased significantly at the T3 and T4 (P <  0.05); TAFI concentrations also decreased at the T5 in low-dose group (P < 0.05). Compared with the low-dose group, the concentration of TM increased significantly at the T4 in high-dose group.

Conclusions

The in-vivo effect of low dose TXA is equivalent to high dose TXA on fibrinolysis parameters in adults with a low bleeding risk undergoing valvular cardiac surgery with cardiopulmonary bypass, and a low dose TXA regimen might be equivalent to high dose TXA for those patients.

Trial registration

ChiCTR-IPR-17010303, Principal investigator: Zhen-feng ZHOU, Date of registration: January 1, 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01234-8.

Functional Testing for Tranexamic Acid Duration of Action Using Modified Viscoelastometry

Introduction

Tranexamic acid (TXA) is the standard medication to prevent or treat hyperfibrinolysis. However, prolonged inhibition of lysis (so-called "fibrinolytic shutdown") correlates with increased mortality. A new viscoelastometric test enables bedside quantification of the antifibrinolytic activity of TXA using tissue plasminogen activator (TPA).

Materials and Methods

Twenty-five cardiac surgery patients were included in this prospective observational study. In vivo, the viscoelastometric TPA test was used to determine lysis time (LT) and maximum lysis (ML) over 96 h after TXA bolus. Additionally, plasma concentrations of TXA and plasminogen activator inhibitor 1 (PAI-1) were measured. Moreover, dose effect curves from the blood of healthy volunteers were performed in vitro. Data are presented as median (25-75th percentile).

Results

In vivo TXA plasma concentration correlated with LT (r = 0.55; p < 0.0001) and ML (r = 0.62; p < 0.0001) at all time points. Lysis was inhibited up to 96 h (LT_TPA-test: baseline: 398 s [229-421 s] vs. at 96 h: 886 s [626-2,175 s]; p = 0.0013). After 24 h, some patients (n = 8) had normalized lysis, but others (n = 17) had strong lysis inhibition (ML <30%; p < 0.001). The high- and low-lysis groups differed regarding kidney function (cystatin C: 1.64 [1.42-2.02] vs. 1.28 [1.01-1.52] mg/L; p = 0.002) in a post hoc analysis. Of note, TXA plasma concentration after 24 h was significantly higher in patients with impaired renal function (9.70 [2.89-13.45] vs.1.41 [1.30-2.34] µg/mL; p < 0.0001). In vitro, TXA concentrations of 10 µg/mL effectively inhibited fibrinolysis in all blood samples.

Conclusions

Determination of antifibrinolytic activity using the TPA test is feasible, and individual fibrinolytic capacity, e.g., in critically ill patients, can potentially be measured. This is of interest since TXA-induced lysis inhibition varies depending on kidney function.

Postoperative administration of tranexamic acid as approach to reduce blood loss after open-heart surgery

BACKGROUND: Tranexamic acid (TXA) reduces perioperative bleeding among patients undergoing heart surgery. It is uncertain whether its postoperative administration, after prior administration before cardiopulmonary bypass (CPB), has an additional benefit. OBJECTIVE: Our study aimed to evaluate whether the postoperative administration of TXA reduces the blood loss after heart surgery. METHODS: In a retrospective cohort study at the University Heart Center Dresden, patients who underwent on-pump open-heart surgery and received 1 g TXA before CPB were included. Patients with postoperative administration of 1 g TXA were compared to patients without. Primary endpoint was the postoperative blood loss within 24 hours. RESULTS: Among 2,179 patients undergoing heart surgery between 1 July 2013 and 31 October 2014, 92 (4.2%) received TXA postoperatively. After matching, 71 patients with postoperative administration of TXA were compared to 71 without (n = 142). Postoperative administration of TXA did not result in decreased blood loss (MD 146.7 mL; p = 0.064). There was no evidence of an increased risk for thromboembolic complications. CONCLUSIONS: The postoperative administration of TXA did not reduce blood loss. The use of TXA was shown to be safe in terms of thromboembolic events and hospital mortality. Unless there is no clear evidence, the postoperative administration of TXA should be restricted to patients with massive blood loss and signs of hyperfibrinolysis only.

A Pharmacokinetic and Pharmacodynamic Investigation of an ε-Aminocaproic Acid Regimen Designed for Cardiac Surgery With Cardiopulmonary Bypass

OBJECTIVE

To investigate the pharmacokinetics and pharmacodynamics of an ε-aminocaproic acid (EACA) regimen designed for cardiac surgery with cardiopulmonary bypass (CPB).

DESIGN

Prospective observational study requiring blood sampling to measure EACA concentrations and fibrinolysis markers (fibrinogen, D-dimer, α₂-antiplasmin, and tissue plasminogen activator-plasminogen activator inhibitor [tPA-PAI-1] complex).

SETTING

Single-center, tertiary medical center.

PARTICIPANTS

Patients who underwent cardiac surgery with CPB between 2018 and 2019 for aortic or mitral valve replacement/repair or coronary artery bypass grafting. Previous sternotomy patients were included.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

The pharmacokinetics of EACA, during CPB, were described by a 3-compartment disposition model. EACA concentrations were greater than 130 mg/L in all patients after CPB and in most patients during CPB. The D-dimer level trended up and reached a peak median level of 1.35 mg/L of fibrinogen equivalence units (FEU) at 15 minutes after protamine administration. The median change in D-dimer (ΔD-dimer) from baseline to 15 minutes after protamine was 0.34 (-0.48 to 3.81) mg/L FEU. ΔD-dimer did not correlate with EACA concentration intraoperatively, urine output, body weight, glomerular filtration rate, cell salvage volume, and ultrafiltration volume. The median 24-hour chest tube output was 445 (180-1,011) mL.

CONCLUSION

This regimen provided maximum EACA concentrations near the time of protamine administration, with a total perioperative dose of 15 g. Most patients had EACA concentrations greater than the target during CPB. ΔD-dimer did not correlate with EACA concentration. The median 24-hour chest tube output compared well to similar studies that used higher doses of EACA.

Outcome impact of different tranexamic acid regimens in cardiac surgery with cardiopulmonary bypass (OPTIMAL): Rationale, design, and study protocol of a multicenter randomized controlled trial

Tranexamic acid (TxA) reduces perioperative blood transfusion in cardiac surgery; however, the optimal dose of TxA remains unknown. METHODS AND RESULTS: This large-scale, double-blind, randomized controlled trial with a 1-year follow-up enrolls patients undergoing elective cardiac surgery with cardiopulmonary bypass. Patients are randomly assigned 1:1 into either the high-dose TxA group (intravenous bolus [30 mg/kg] after anesthesia followed by intravenous maintenance [16 mg/kg/h] throughout the operation, and a pump prime dose of 2 mg/kg) or the low-dose TxA group (intravenous bolus and maintenance are 10 mg/kg and 2 mg/kg/h, respectively, and a pump prime dose of 1 mg/kg). The primary efficacy end point is the rate of perioperative allogeneic red blood cell (RBC) transfusion defined as the number (%) of patients who will receive at least 1 RBC unit from operation day to discharge. The primary safety end point is the 30-day rate of the composite of perioperative seizures, renal dysfunction, myocardial infarction, ischemic stroke, deep vein thrombosis, pulmonary embolism, and all-cause mortality. The secondary end points are perioperative allogeneic RBC transfusion volume, the non-RBC blood transfusion rate, postoperative bleeding, reoperation rate, mechanical ventilation duration, intensive care unit stay, hospital length of stay, total hospitalization cost, each component of composite primary safety end point, and the 6-month/1-year follow-up mortality and morbidity. We estimated a sample size of 3,008 participants. CONCLUSIONS: The study is designed to identify a TxA dose with maximal efficacy and minimal complications. We hypothesize that the high dose has superior efficacy and noninferior safety to the low dose.

Antifibrinolytics and cardiac surgery: The past, the present, and the future

Cardiac surgery is usually associated with significant blood loss, which often necessitates blood transfusion. In order to decrease the risks associated with the latter, pharmacological as well as nonpharmacological strategies have been used to reduce blood loss. Among the pharmacological approaches, antifibrinolytic drugs are the mainstay. Aprotinin, which was the first ubiquitously used drug, fell into disrepute only to re-emerge after much debate. The decline of aprotinin paved the way for the lysine analogs. However, we must be aware with the side effects of these drugs as well as the dose modification required in special situations. Nonsaccharide glycosaminoglycans have been under investigation to overcome the drawbacks of the lysine analogs. It remains to be seen whether these drugs can replace the traditional antifibrinolytics.

Tranexamic acid in cardiac surgery: a systematic review and meta-analysis (protocol)

INTRODUCTION

Bleeding during cardiac surgery is associated with increased morbidity and mortality. Tranexamic acid is an antifibrinolytic with proven efficacy in major surgeries. Current clinical practice guidelines recommend intraoperative use in cardiac procedures. However, several complications have been reported with tranexamic acid including seizures. This review intends to summarise the evidence examining the efficacy and safety of tranexamic acid in patients undergoing cardiac surgery.

METHODS/DESIGN

We will search MEDLINE, Embase, PubMED, ACPJC, CINAHL and the Cochrane trial registry for eligible randomised controlled trials, the search dates for all databases will be from inception until 1 January 2019, investigating the perioperative use of topical and/or intravenous tranexamic acid as a stand-alone antifibrinolytic agent compared with placebo in patients undergoing open cardiac surgery. We categorised outcomes as patient critical or patient important. Selected patient-critical outcomes are: mortality (intensive care unit, hospital and 30-day endpoints), reoperation within 24 hours, postoperative bleeding requiring transfusion of packed red blood cells, myocardial infarction, stroke, pulmonary embolism, bowel infarction, upper or lower limb deep vein thrombosis and seizures. Those outcomes, we perceived as clinical experts to be most patient valued and patients were not involved in outcomes selection process. We will not apply publication date, language, journal or methodological quality restrictions. Two reviewers will independently screen and identify eligible studies using predefined eligibility criteria and then review full reports of all potentially relevant citations. A third reviewer will resolve disagreements if consensus cannot be achieved. We will present the results as relative risk with 95% CIs for dichotomous outcomes and as mean difference or standardised mean difference for continuous outcomes with 95% CIs. We will assess the quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach.

ETHICS AND DISSEMINATION

Formal ethical approval is not required as primary data will not be collected. The results will be disseminated through a peer-reviewed publication TRIAL REGISTRATION NUMBER: CRD42018105904.

Tranexamic acid and perioperative bleeding in children: what do we still need to know?

PURPOSE OF REVIEW

Perioperative bleeding and blood product transfusion are associated with significant morbidity and mortality. Prevention and optimal management of bleeding decreases risk and lowers costs. Tranexamic acid (TXA) is an antifibrinolytic agent that reduces bleeding and transfusion in a broad number of adult and pediatric surgeries, as well as in trauma and obstetrics. This review highlights the current pediatric indications and contraindications of TXA. The efficacy and safety profile, given current and evolving research, will be covered.

RECENT FINDINGS

Based on the published evidence, prophylactic or therapeutic TXA administration is a well-tolerated and effective strategy to reduce bleeding, decrease allogeneic blood product transfusion, and improve pediatric patients' outcomes. TXA is now recommended in recent guidelines as an important part of pediatric blood management protocols.

SUMMARY

Based on TXA pharmacokinetics, the authors recommend a dosing regimen of between 10 to 30 mg/kg loading dose followed by 5 to 10 mg/kg/h maintenance infusion rate for pediatric trauma and surgery. Maximal efficacy and minimal side-effects with this dosage regime will have to be determined in larger prospective trials including high-risk groups. Furthermore, future research should focus on determining the ideal TXA plasma therapeutic concentration for maximum efficacy and minimal side-effects.

Patient Blood Management in Pediatric Cardiac Surgery: A Review

Efforts to reduce blood product transfusions and adopt blood conservation strategies for infants and children undergoing cardiac surgical procedures are ongoing. Children typically receive red blood cell and coagulant blood products perioperatively for many reasons, including developmental alterations of their hemostatic system, and hemodilution and hypothermia with cardiopulmonary bypass that incites inflammation and coagulopathy and requires systemic anticoagulation. The complexity of their surgical procedures, complex cardiopulmonary interactions, and risk for inadequate oxygen delivery and postoperative bleeding further contribute to blood product utilization in this vulnerable population. Despite these challenges, safe conservative blood management practices spanning the pre-, intra-, and postoperative periods are being developed and are associated with reduced blood product transfusions. This review summarizes the available evidence regarding anemia management and blood transfusion practices in the perioperative care of these critically ill children. The evidence suggests that adoption of a comprehensive blood management approach decreases blood transfusions, but the impact on clinical outcomes is less well studied and represents an area that deserves further investigation.

Different dose regimes and administration methods of tranexamic acid in cardiac surgery: a meta-analysis of randomized trials

BACKGROUND

The efficacy of tranexamic acid (TXA) to reduce perioperative blood loss and allogeneic blood transfusion in cardiac surgeries has been proved in previous studies, but its adverse effects especially seizure has always been a problem of concern. This meta-analysis aims to provide information on the optimal dosage and delivery method which is effective with the least adverse outcomes.

METHODS

We searched Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE for all relevant articles published before 2018/12/31. Inclusion criteria were adult patients undergoing elective heart surgeries, and only randomized control trials comparing TXA with placebo were considered. Two authors independently assessed trial quality and extracted relevant data.

RESULTS

We included 49 studies with 10,591 patients into analysis. TXA significantly reduced transfusion rate (RR 0.71, 95% CI 0.65 to 0.78, P<0.00001). The overall transfusion rate was 35%(1573/4477) for patients using TXA and 49%(2190/4408) for patients in the control group. Peri-operative blood loss (MD - 246.98 ml, 95% CI - 287.89 to - 206.06 ml, P<0.00001) and re-operation rate (RR 0.62, 95% CI 0.49 to 0.79, P<0.0001) were also reduced significantly. TXA usage did not increase risk of mortality, myocardial infarction, stroke, pulmonary embolism and renal dysfunction, but was associated with a significantly increase in seizure attack (RR 3.21, 95% CI 1.04 to 9.90, P = 0.04).The overall rate of seizure attack was 0.62%(21/3378) for patients using TXA and 0.15%(5/3406) for patients in the control group. In subgroup analysis, TXA was effective for both on-pump and off-pump surgeries. Topical application didn't reduce the need for transfusion requirement, while intravenous delivery no matter as bolus injection alone or bolus plus continuous infusion were effective. Intravenous high-dose TXA didn't further decrease transfusion rate compared with low-dose regimen, and increased the risk of seizure by 4.83 times. No patients in the low-dose group had seizure attack.

CONCLUSIONS

TXA was effective in reducing transfusion requirement in all kinds of cardiac surgeries. Low-dose intravenous infusion was the most preferable delivery method which was as effective as high-dose regimen in reducing transfusion rate without increasing the risk of seizure.

Prophylactic use of tranexamic acid reduces blood loss and transfusion requirements in patients undergoing cesarean section: A meta-analysis

AIM

Tranexamic acid (TXA) has been used to treat peripartum hemorrhage, while preoperative use of TXA in cesarean section (CS) remains controversial. To assess the effectiveness and safety of prophylactic application of TXA, a meta-analysis was performed.

METHODS

Electronic databases (MEDLINE [PubMed], Cochrane central register of controlled trials and Embase) were searched up to November 2018. The relevant data and quality of included trail were analyzed by RevMan 5.3. The study was registered at PROSPERO (CRD42018111165).

RESULTS

Twenty-one randomized controlled trials with a total of 3852 patients were included. Only one research reported thromboembolic events. Compared with control groups, the intra-operative blood loss (mean difference [MD] -155.23 mL, 95% confidence interval [CI] -195.64 - 114.81; P<0.01), postoperative blood loss (MD -26.67 mL, 95% CI -32.98 to -20.36; P<0.01), total blood loss (MD -184.88 mL, 95% CI -218.83 to -150.94; P<0.01), transfusion requirements (relative risk [RR] 0.29, 95% CI 0.18-0.49, P<0.01), massive hemorrhage (RR 0.39, 95% CI 0.30 to 0.51; P<0.01) and additional uterotonic agents use (RR 0.40, 95% CI 0.30-0.55, P<0.01) were markedly reduced in TXA-treated patients. Besides, TXA yielded a significant reduction in hemoglobin drop (MD -0.80 g/dL, 95% CI -1.07 to -0.53; P<0.01) and hematocrit drop (MD -2.05, 95% CI -3.09 to -1.01; P<0.01) compared with control groups.

CONCLUSION

Prophylactic application of TXA can decrease perioperative blood loss and transfusion requirements in patients undergoing CS. More high-quality researches are needed to determine optimal dose of the drug.

Efficacy and safety of antifibrinolytic agents in spinal surgery: a network meta-analysis

Background:

Significant blood loss is still one of the most frequent complications in spinal surgery, which often necessitates blood transfusion. Massive perioperative blood loss and blood transfusion can create additional risks. Aprotinin, tranexamic acid (TXA), and epsilon-aminocaproic acid (EACA) are antifibrinolytics currently offered as prophylactic agents to reduce surgery-associated blood loss. The aim of this study was to evaluate the efficacy and safety of aprotinin, EACA, and low/high doses of TXA in spinal surgery, and assess the use of which agent is the most optimal intervention using the network meta-analysis (NMA) method.

Methods:

Five electronic databases were searched, including PubMed, Cochrane Library, ScienceDirect, Embase, and Web of Science, from the inception to March 1, 2018. Trials that were randomized and compared results between TXA, EACA, and placebo were identified. The NMA was conducted with software R 3.3.2 and STATA 14.0.

Results:

Thirty randomized controlled trial (RCT) studies were analyzed. Aprotinin (standardized mean difference [SMD]=−0.65, 95% credibility intervals [CrI;−1.25, −0.06]), low-dose TXA (SMD = −0.58, 95% CrI [−0.92, −0.25]), and high-dose TXA (SMD = −0.70, 95% CrI [−1.04, −0.36]) were more effective than the respective placebos in reducing intraoperative blood loss. Low-dose TXA (SMD = −1.90, 95% CrI [−3.32, −0.48]) and high-dose TXA (SMD = −2.31, 95% CrI [−3.75, −0.87]) had less postoperative blood loss. Low-dose TXA (SMD = −1.07, 95% CrI [−1.82, −0.31]) and high-dose TXA (SMD = −1.07, 95% CrI [−1.82, −0.31]) significantly reduced total blood loss. However, only high-dose TXA (SMD = −2.07, 95% CrI [−3.26, −0.87]) was more effective in reducing the amount of transfusion, and was significantly superior to low-dose TXA in this regard (SMD = −1.67, 95% CrI [−3.20, −0.13]). Furthermore, aprotinin (odds ratio [OR] = 0.16, 95% CrI [0.05, 0.54]), EACA (OR = 0.46, 95% CrI [0.22, 0.97]) and high dose of TXA (OR = 0.34, 95% CrI [0.19, 0.58]) had a significant reduction in transfusion rates. Antifibrinolytics did not show a significantly increased risk of postoperative thrombosis. Results of ranking probabilities indicated that high-dose TXA had the greatest efficacy and a relatively high safety level.

Conclusions:

The antifibrinolytic agents are able to reduce perioperative blood loss and transfusion requirement during spine surgery. And the high-dose TXA administration might be used as the optimal treatment to reduce blood loss and transfusion.

What concentration of tranexamic acid is needed to inhibit fibrinolysis? A systematic review of pharmacodynamics studies

: Intravenous tranexamic acid (TXA) reduces death because of bleeding in patients with trauma and postpartum haemorrhage. However, in some settings intravenous injection is not feasible. To find different routes of administration, we first need to determine the minimal concentration of TXA in the blood that is required to inhibit fibrinolysis.We conducted a systematic review of in-vitro and in-vivo pharmacodynamics studies. We searched MEDLINE, EMBASE, OviSP, and ISI Web of Science from database inception to November 2017 for all in-vitro (including simulated clotting models) or in-vivo studies reporting the relationship between the TXA concentration in blood or plasma and any reliable measure of fibrinolysis.We found 21 studies of which 20 were in vitro and one was in vivo. Most in-vitro studies stimulated fibrinolysis with tissue plasminogen activator and measured fibrinolysis using viscoelastic, optical density, or immunological assays. TXA concentrations between 10 and 15 mg/l resulted in substantial inhibition of fibrinolysis, although concentrations between 5 and 10 mg/l were partly inhibitory.TXA concentrations of 10-15 mg/l may be suitable targets for pharmacokinetic studies, although TXA concentrations above 5 mg/l may also be effective.

Current Understanding of How Extracorporeal Membrane Oxygenators Activate Haemostasis and Other Blood Components

Extracorporeal membrane oxygenators are used in critical care for the management of severe respiratory and cardiac failure. Activation of the coagulation system is initiated by the exposure of blood to synthetic surfaces and the shear stresses of the circuit, especially from device pumps. Initial fibrinogen deposition and subsequent activation of coagulation factors and complement allow platelets and leucocytes to adhere to oxygenator surfaces and enhance thrombin generation. These changes and others contribute to higher rates of thrombosis seen in these patients. In addition, bleeding rates are also high. Primary haemostasis is impaired by platelet dysfunction and loss of their key adhesive molecules and shear stress causes an acquired von Willebrand defect. In addition, there is also altered fibrinolysis and lastly, administration of systemic anticoagulation is required to maintain circuit patency. Further research is required to fulyl establish the complexities of the haemostatic changes with these devices, and to elucidate the mechanistic changes that are mainly responsible so that plans can be made to reduce their complications and improve management.

Exclusion criteria and adverse events in perioperative trials of tranexamic acid: a systematic review and meta-analysis

BACKGROUND

Tranexamic acid (TXA) is an inexpensive therapy effective at minimizing perioperative blood loss and transfusion. However, it remains underutilized due to safety concerns. To date, no evidence-based guidelines exist identifying which patients should not receive TXA therapy. This study determined patient groups for whom safety information regarding TXA is lacking due to common exclusion from perioperative TXA trials.

STUDY DESIGN AND METHODS

A systematic review searching the databases Medline, EMBASE, CENTRAL, and Clinicaltrials.gov was performed. Randomized controlled trials (RCTs) administering systemic TXA perioperatively to elective or emergent surgery patients were eligible. Our primary outcome was to describe exclusion criteria of RCTs, and the secondary outcome was TXA safety. A descriptive synthesis of exclusion criteria was performed, and TXA safety was assessed by meta-analysis.

RESULTS

A total of 268 eligible RCTs were included. Meta-analysis showed that systemic TXA did not increase risk of adverse events compared to placebo or no intervention (relative risk, 1.05; 95% confidence interval, 0.99-1.12). Patient groups commonly excluded from perioperative TXA trials, and thus potentially lacking TXA safety data, were those with major comorbidities, a history of thromboembolism, medication use affecting coagulation, TXA allergy, and coagulopathy. Exclusion of patients with major comorbidities may not be necessary; we showed that the risk of adverse events was similar in studies that excluded patients with major comorbidities and those that did not.

CONCLUSION

Sufficient evidence exists to develop perioperative guidelines for TXA use in many populations. Further studies evaluating perioperative TXA use in patients with a history of thromboembolism are warranted.

TRAnexamic acid in hemorrhagic CESarean section (TRACES) randomized placebo controlled dose-ranging pharmacobiological ancillary trial: study protocol for a randomized controlled trial

BACKGROUND

Evidence increases that a high or a standard dose of tranexamic acid (TA) reduces postpartum bleeding. The TRACES pharmacobiological substudy aims to establish a therapeutic strategy in hemorrhagic (H) Cesarean section (CS) with respect to the intensity of fibrinolysis by using innovative assays.

METHOD/DESIGN

The TRACES trial is a multicenter, randomized, double-blind, placebo-controlled, TA dose-ranging study that measures simultaneously plasmatic and uterine and urine TA concentrations and the plasmin peak inhibition tested by a simultaneous thrombin plasmin generation assay described by Van Geffen (novel hemostasis assay [NHA]). Patients undergoing H CS (>800 mL) will receive blindly TA 0.5 g or 1 g or placebo. A non-hemorrhagic (NH) group will be recruited to establish plasmin generation profile. Venous blood will be sampled before, at the end, and then at 30, 60, 120, and 360 min after injection. Uterine bleeding will be sampled after injection. Urine will be sampled 2 h and 6 h after injection. The number of patients entered into the study will be 114 H + 48 NH out of the 390 patients of the TRACES clinical trial.

DISCUSSION

To explore the two innovative assays, a preliminary pilot study was conducted. Blood samples were performed repeatedly in patients undergoing either a H (>800 mL) or NH (<800 mL) CS and in non-pregnant women (NP). H patients received TA (0-2 g). Dose-dependent TA plasmatic concentrations were determined by LC-MS/MS quantification. Plasmin generation and its inhibition were tested in vitro and in vivo using the simultaneous thrombin-plasmin generation assay (STPGA). The pilot study included 15 patients in the H group, ten patients in the NH group, and seven patients in the NP group. TA plasmatic concentration showed a dose-dependent variation. STPGA inter-assay variation coefficients were < 20% for all plasmin parameters. Inter-individual dispersion of plasmin generation capacity was higher in H and NH groups than in NP group. Profile evolution over time was different between groups. This preliminary technical validation study allows TRACES pharmacobiological trial to be conducted.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02797119. Registered on 13 June 2016.

Single intravenous bolus versus perioperative continuous infusion of tranexamic acid to reduce blood loss in abdominal oncosurgical procedures: A prospective randomized double-blind clinical study

Background and Aims:

Intraoperative use of a single bolus dose of tranexamic acid may not be sufficient to prevent bleeding in the early postoperative period. The present study was carried out to compare the effect of two dose regimens of tranexamic acid in reducing perioperative blood loss and the amount of allogenic blood transfusion in abdominal tumor surgery.

Material and Methods:

In this prospective, controlled, and double-blind investigation, 60 patients electively posted for abdominal oncosurgical procedures were randomly assigned to receive a single bolus dose of tranexamic acid (10 mg/kg) (Group A), a bolus dose of tranexamic acid (10 mg/kg) followed by infusion (1 mg/kg/h) till 4 h postoperatively (Group B), and a bolus followed by infusion of normal saline (group C). Total intraoperative blood loss, amount of allogenic blood transfusion, postoperative drain collections, and hemoglobin and hematocrit levels were recorded at different time intervals. Data obtained after comparing three groups were analyzed by analysis of variance test for variables following normal distribution, Kruskal–Wallis test for nonparametric data, and post-hoc Tukey–Kramer test for intergroup analysis. A probability value of less than 5% was considered significant.

Results:

There was no significant difference in intraoperative blood loss in all the three groups. Both the tranexamic acid groups showed reduction in postoperative blood collection in drain at 6 h and 24 h in comparison to the control group (P < 0.001). There was also a significant difference in the amount of blood in postoperative drain at 24 h within the tranexamic acid groups, where lesser collection was seen in the infusion group (P = 0.007). Hemoglobin and hematocrit levels measured at different postoperative time intervals showed a significant reduction from the baseline in the control group compared to the tranexamic acid groups together.

Conclusion:

Tranexamic acid causes more effective reduction in post-operative blood loss when used as a bolus followed by an infusion continued in the postoperative period in comparison to its use as a single intravenous bolus in abdominal tumor surgery.