Efficacy of tranexamic acid in reducing blood loss after cesarean section

Role of prophylactic tranexamic acid in reducing blood loss during cesarean section: A double-blind placebo-controlled randomized controlled trial

Background

Postpartum hemorrhage (PPH) is defined by the World Health Organization as blood loss of ≥500 mL within 24 h of delivery. Globally, hemorrhage accounts for 27.1% of maternal deaths, making it the leading direct cause of maternal death. PPH has been identified in more than two-thirds of reported hemorrhage-related deaths, causing 38% of maternal deaths in India. Tranexamic acid, an antifibrinolytic, has been used to control bleeding after PPH is identified.

Materials and Methods

Antenatal women admitted for elective cesarean section were randomized into two arms: the case group (received one gram of tranexamic acid 20 min prior to skin incision) and the control group (received a placebo), each group consisting of 36 participants. Clinical Trials Registry - India (CTRI) registration number - CTRI/2021/02/031579.

Results

The mean (±standard deviation [SD]) intraoperative blood loss in the case group was 241.25 (±67.83) mL, and in the control group, it was 344.92 (±146.67) mL (P = 0.001), while postoperative blood loss did not differ significantly between the groups (P = 0.1470). In terms of the difference in hemoglobin, there was a significant difference between the two groups (P = 0.001). No significant maternal or neonatal side effects were found.

Conclusion

Preoperative tranexamic acid, when given in elective cesarean section, significantly reduces intraoperative blood loss.

Efficacy and safety of tranexamic acid in prevention of postpartum hemorrhage: a systematic review and meta-analysis of 18,649 patients

BACKGROUND

In this meta-analysis, we aimed to update the clinical evidence regarding the efficacy and safety of TXA in the prevention of PPH.

METHODS

A literature search of PubMed, Scopus, Web of Science, Google Scholar, and Cochrane Library from inception until December 2022 was conducted. We included randomized controlled trials (RCTs) comparing TXA with a placebo among pregnant women. All relevant outcomes, such as total blood loss, the occurrence of nausea and/or vomiting, and changes in hemoglobin, were combined as odds ratios (OR) or mean differences (MD) in the meta-analysis models using STATA 17 MP.

RESULTS

We included 59 RCTs (18,649 patients) in this meta-analysis. For cesarean birth, TXA was favored over the placebo in reducing total blood loss (MD= -2.11 mL, 95%CI [-3.09 to -1.14], P < 0.001), and occurrence of nausea or/and vomiting (OR = 1.36, 95%CI [1.07 to 1.74], P = 0.01). For vaginal birth, the prophylactic use of TXA was associated with lower total blood loss, and higher occurrence of nausea and/or vomiting (MD= -0.89 mL, 95%CI [-1.47 to -0.31], OR = 2.36, 95%CI [1.32 to 4.21], P = 0.02), respectively. However, there were no differences between the groups in changes in hemoglobin during vaginal birth (MD = 0.20 g/dl, 95%CI [-0.07 to 0.48], P = 0.15). The overall risk of bias among the included studies varies from low to high risk of bias using ROB-II tool for RCTs.

CONCLUSIONS

This meta-analysis suggested that TXA administration is effective among women undergoing cesarean birth or vaginal birth in lowering total blood loss and limiting the occurrence of PPH. Further clinical trials are recommended to test its efficacy on high-risk populations.

Effect of preoperative prophylactic intravenous tranexamic acid on perioperative blood loss control in patients undergoing cesarean delivery: a systematic review and meta-analysis

BACKGROUND

Postpartum hemorrhage (PPH) is one of the important risk factors leading to maternal mortality and intervention is essential. Oxytocin therapy is widely used clinically, but the effect is unsatisfactory. The efficacy of tranexamic acid (TXA) in hemostasis is notable, whereas its use in preventing PPH warrants exploration.

AIMS

To evaluate the effect of prophylactic administration of TXA on perioperative blood loss in women undergoing cesarean section by systematic review and meta-analysis of published studies.

METHODS

Bibliographic databases were screened from their inception to December 2022 to retrieve relevant studies. Study outcomes including blood loss during cesarean section, 2-h postpartum blood loss, total blood loss (during cesarean section and 2-h postpartum), and 6-h postpartum, as well as hemoglobin changes were extracted and compared.

RESULTS

A total of 21 studies, nine randomized clinical trials and 12 cohort studies, involving 1896 patients given TXA prophylactically and 1909 patients given placebo or no treatment, were analyzed. Compared with the control group, the preoperative prophylactic intravenous administration of TXA significantly reduced the intraoperative (RCT: P < 0.00001, cohort studies: P < 0.00001), 2-h postpartum (RCT: P = 0.02, cohort studies: P < 0.00001) and total blood loss (RCT: P < 0.00001, cohort studies: P = 0.0002), and reduced the decline in hemoglobin (RCT: P < 0.00001, cohort studies: P = 0.0001), but did not significantly affect blood loss at 6-h postpartum (P = 0.05).

CONCLUSION

Prophylactic intravenous TXA before cesarean section is helpful in preventing perioperative bleeding in women.

TRIAL REGISTRATION

http://www.crd.york.ac.uk/PROSPERO , identifier: CRD 42022363450.

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.

Clinical Outcomes and Experience of a Multiyear Consecutive Case Series of Total Knee Arthroplasty Procedures Conducted with a Bipolar Sealer System for Hemostasis

Maximizing hemostasis during total knee replacement procedures remains a key challenge in current practice. Bipolar sealer technology achieves intraoperative hemostasis through tissue sealing and coagulation with adjustable radio frequency energy and a saline-irrigated tip. Optimal surgical site hemostasis is important to avoid potential complications such as hemarthrosis, wound drainage, increased pain, delayed discharge, and readmissions. The aim of this study is to evaluate the safety and effectiveness of the bipolar sealer device in primary knee replacement in the largest consecutive series to date. A consecutive, treatment-control series of subjects who underwent a primary total knee arthroplasty (TKA) utilizing a bipolar sealer for hemostasis, one subgroup with concomitant tranexamic acid (TXA) administration (n = 1599) and one subgroup without TXA administration (n = 3582), compared with a control group of primary TKA under tourniquet only (n = 667). Statistical analyses were performed through two-tailed unpaired t-tests. There was less total postoperative drain output and a lower overall transfusion rate in the bipolar sealer group (807ml ± 428) (2.5%) than the tourniquet only group (1290 ± 658, p = 0.001) (8.4%, p = 0.0001), respectively. Drainage output in bipolar sealer + TXA (450 ± 297 ml) was lower than the other two groups (bipolar sealer 807 ± 428 mL, p = 0.0001; tourniquet only 1290 ± 658 ml, p = 0.0001). The bipolar sealer group had a higher hematocrit at postoperative day 1 (POD1) (bipolar sealer: 33.1 ± 4.3 cc, tourniquet only: 32.5 ± 4.3 cc, p = 0.001) and at discharge (POD2, bipolar sealer: 31.5 ± 3.7 cc, tourniquet only: 30.2 ± 3.9 cc, p = 0.0001). There were zero reported serious adverse events related to hemostasis management in any group. The bipolar sealer system is a safe and effective instrument to achieve intraoperative hemostasis during primary TKA. The bipolar sealer group required significantly fewer postoperative blood product transfusions and maintained a higher hematocrit concentration at the time of discharge compared with subjects treated solely with tourniquet mediated hemostasis. Addition of TXA to local hemostasis methods may further reduce blood loss and transfusion requirements. LEVEL OF EVIDENCE:  This is a Level III study.

Analysis of the efficacy of prophylactic tranexamic acid in preventing postpartum bleeding: systematic review with meta-analysis of randomized clinical trials

BACKGROUND

Postpartum Hemorrhage (PPH) is one of the main causes of maternal mortality, mainly in the poorest regions of the world, drawing attention to the need for strategies for preventing it. This study aims to evaluate the efficacy of prophylactic administration of Tranexamic Acid (TXA) in decreasing blood loss in pregnant women in delivery, preventing PPH.

METHODS

Systematic review of randomized clinical trials. We searched for publications in PubMed, EMBASE and Cochrane Library databases, with the uniterms "postpartum, puerperal hemorrhage" and "tranexamic acid", published between January of 2004 and January of 2020. The eligibility criteria were trials published in English with pregnant women assessed during and after vaginal or cesarean delivery about the effect of prophylactic use of TXA on bleeding volume. The random-effects model was applied with the DerSimonian-Laird test and the Mean Difference (MD) was calculated for continuous variables together with each 95% CI. This systematic review was previously registered in the PROSPERO platform under the registration n° CRD42020187393.

RESULTS

Of the 630 results, 16 trials were selected, including one with two different doses, performing a total of 6731 patients. The intervention group received a TXA dose that varied between 10 mg.kg^-1 and 1g (no weight calculation). The TXA use was considered a protective factor for bleeding (MD: -131.07; 95% CI: -170.00 to -92.78; p = 0.000) and hemoglobin variation (MD: -0.417; 95% CI: -0.633 to -0.202; p = 0.000). In the subgroup analysis related to the cesarean pathway, the effect of TXA was even greater.

CONCLUSION

The prophylactic use of tranexamic acid is effective in reducing the post-partum bleeding volume.

PROSPERO REGISTRATION ID

CRD42020187393.

Tranexamic acid for the prevention of postpartum hemorrhage in women undergoing cesarean delivery: an updated meta-analysis

OBJECTIVE

This study aimed to assess the efficacy and safety of prophylactic tranexamic acid administration vs standard uterotonic agents alone among women undergoing cesarean delivery.

DATA SOURCES

MEDLINE, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and Google Scholar were systematically searched from inception to June 30, 2021.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials comparing intravenous tranexamic acid administration with placebo in women undergoing cesarean delivery and receiving standard prophylactic uterotonic agents were held eligible.

STUDY APPRAISAL AND SYNTHESIS METHODS

The risk of bias of individual studies was appraised with the Risk of Bias 2 tool. Meta-analysis was conducted by fitting random-effects models using restricted maximum likelihood. Subgroup analysis was performed on the basis of country, protocol availability, double-blinding, risk of bias, sample size, and tranexamic acid dose. A 1-stage meta-analysis was performed as a sensitivity analysis. The credibility of outcomes was appraised with the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Overall, 36 studies with 10,659 women were included. Tranexamic acid administration was associated with significantly lower total blood loss (mean difference, -189.44 mL; 95% confidence intervals, -218.63 to -160.25), lower hemoglobin drop (mean difference, 8.22%; 95% confidence interval, 5.54-10.90), decreased risk of blood loss of >1000 mL (odds ratio, 0.37; 95% confidence interval, 0.22-0.60), transfusion requirement (odds ratio, 0.41; 95% confidence interval, 0.26-0.65), and need of additional uterotonics (odds ratio, 0.36; 95% confidence interval, 0.25-0.52). Subgroup analysis indicated a greater effect of tranexamic acid on total blood loss reduction in low-middle income countries. The outcomes remained stable by separately evaluating women at low bleeding risk. The 1-stage meta-analysis demonstrated similar outcomes with the primary analysis. The quality of evidence was judged to be moderate regarding total blood loss and hemoglobin percentage change and low for the other outcomes.

CONCLUSION

This meta-analysis suggested that prophylactic tranexamic acid administration is effective among women undergoing cesarean delivery in lowering postpartum blood loss and limiting hemoglobin drop. Further research is needed to test its efficacy in high-risk populations and verify its safety profile.

Tranexamic Acid for Prevention of Hemorrhage in Elective Repeat Cesarean Delivery - A Randomized Study

BACKGROUND

The American College of Obstetricians and Gynecologists states that data is insufficient to recommend Tranexamic acid (TXA) prophylaxis for postpartum hemorrhage.

OBJECTIVE

This study's objective was to evaluate if prophylactic TXA reduces calculated blood loss versus placebo in women undergoing elective repeat cesarean delivery.

STUDY DESIGN

A double-blind, randomized, placebo-controlled trial, examining calculated blood loss with prophylactic doses of 1-gram of TXA given before skin incision and after placental delivery and standard uterotonics in women with singleton pregnancies at least 37 weeks' gestation, presenting for their second or third cesarean delivery under neuraxial anesthesia. The primary outcome was calculated blood loss at 24 hours. The calculation was based on the participant's height, weight, and the difference in hematocrit before the start of surgery and 24 hours after delivery. Prespecified secondary outcomes were quantification of maternal coagulation activity during the perioperative course. A sample size of 50 women per group was planned (N=100), based on a meta-analysis of mean reduction in blood loss after TXA.

RESULTS

723 women were screened, and 110 women were randomized as follows: 55 to TXA and 55 to placebo. The primary outcome of mean calculated blood for TXA (2274 ± 469 mL) and the placebo group (2407 ± 388 mL), p > 0.05. In the secondary outcomes, D-dimer levels were lower in the TXA group than the placebo group 24 hours after delivery (2.1 ± 1.2 µg/mL versus 4.3 ± 2.4 µg/mL), p < 0.001.

CONCLUSIONS

Prophylactic tranexamic acid did not decrease mean calculated blood loss. Significantly less participants had calculated blood loss greater than 2000 mL in the tranexamic acid group compared to the placebo group with lower levels of D-dimer at 24 hours.

Tranexamic acid for prevention of bleeding in cesarean delivery: An overview of systematic reviews

BACKGROUND

Bleeding is the leading cause of maternal mortality in the world. Tranexamic acid reduces bleeding in trauma and surgery. Several systematic reviews of randomized trials have investigated tranexamic acid in the prevention of bleeding in cesarean delivery. However, the conclusions from systematic reviews are conflicting. This overview aims to summarize the evidence and explore the reasons for conflicting conclusions across the systematic reviews.

METHODS

A comprehensive literature search of Medline, Embase, and Cochrane Database of Systematic Reviews was conducted from inception to April 2021. Screening, data extraction, and quality assessments were performed by two independent reviewers. A Measurement Tool to Assess Reviews 2 and the Risk of Bias Assessment Tool for Systematic Reviews were used for study appraisal. A qualitative synthesis of evidence is presented.

RESULTS

In all, 14 systematic reviews were included in our analysis. Across these reviews, there were 32 relevant randomized trials. A modest reduction in blood transfusions and bleeding outcomes was found by most systematic reviews. Overall confidence in results varied from low to critically low. All of the included systematic reviews were at high risk of bias. Quality of evidence from randomized trials was uncertain.

CONCLUSIONS

Systematic reviews investigating prophylactic tranexamic acid in cesarean delivery are heterogeneous in terms of methodological and reporting quality. Tranexamic acid may reduce blood transfusion and bleeding outcomes, but rigorous well-designed research is needed due to the limitations of the included studies. Data on safety and adverse effects are insufficient to draw conclusions.

Effectiveness and Adverse Effects of Tranexamic Acid in Bleeding during Adenotonsillectomy: A Randomized, Controlled, Double-blind Clinical Trial

Introduction  Intra and postoperative bleeding are the most frequent and feared complications in adenotonsillectomy (AT). Tranexamic acid (TXA), which is known for its antifibrinolytic effects, has a proven benefit in reducing bleeding in hemorrhagic trauma and cardiac surgery; however, the effectiveness and timing of its application in AT have not yet been established.

Objectives  We aimed to evaluate the efficacy of TXA in controlling bleeding during and after AT and assess its possible adverse effects in children.

Methods  The present randomized, controlled, double-blind clinical trial included 63 children aged 2 to 12 years. They were randomly assigned to receive either intravenous TXA (10 mg/kg) or placebo 10 minutes before surgery. The volume of intraoperative bleeding, presence of postoperative bleeding, and adverse effects during and 8 hours after the surgery were assessed.

Results  No difference in bleeding volume was noted between the 2 groups (mean, 122.7 ml in the TXA group versus 115.5 ml in the placebo group, p  = 0.36). No intraoperative or postoperative adverse effects were noted because of TXA use. Furthermore, no primary or secondary postoperative bleeding was observed in any of the participants.

Conclusion  In our pediatric sample, TXA (10 mg/kg) administration before AT was safely used, without any adverse effects. It did not reduce the bleeding volume in children during this type of surgery. Future studies should assess the use of higher doses of TXA and its administration at other time points before or during surgery.

Effectiveness of preoperative tranexamic acid in reducing blood loss during caesarean section at Aminu Kano Teaching Hospital, Kano: a randomized controlled trial

Introduction

bleeding during and after caesarean section is one of the contributors to maternal mortality and morbidity. Tranexamic acid can be given before surgery to significantly reduce the amount of blood loss during caesarean section. The objective was to evaluate the effectiveness of preoperative tranexamic acid in reducing blood loss during caesarean section at Aminu Kano Teaching Hospital, Kano.

Methods

this was a randomized double blind placebo controlled study that was carried out among 244 women who were to have emergency caesarean section between December 2017 and June 2018 and were randomly assigned to the study group or control group. Women in the study group received lg (10mls) of tranexamic acid intravenously while women in the control group received 10ml of normal saline. Oxytocin was administered in the two groups according to protocol. Measurement of blood loss was done immediately after surgery. Postoperative drop in haemoglobin and haematocrit were also determined. Statistical analysis was done using SPSS Version 22.

Results

the average intra operative blood loss was 414.0 ml in the study group and 773.8 ml in the control group (t = - 16.18, p ≤ 0.01). Average postoperative haemoglobin was 10.1 g/dl in the study group and 9.5 g/dl in the control group (t = 4.99, p ≤ 0.01). Average postoperative haematocrit was 31.5% in the study group and 29.9% in the control group (t = 4.70, p ≤ 0.01).

Conclusion

there was a significant reduction in the blood loss when preoperative tranexamic acid was given to patients who were to undergo emergency caesarean section.

Tranexamic acid and obstetric hemorrhage: give empirically or selectively?

Antifibrinolytic agents such as tranexamic acid (TXA) inhibit the fibrinolytic pathway and protect blood clots from being degraded, thereby promoting hemostasis. They have been used to reduce blood loss in various settings including obstetrics. Based on current evidence, TXA can be considered as a therapeutic adjunct to control postpartum hemorrhage (PPH) after vaginal and cesarean deliveries, with earlier administration preferred. This strategy has been demonstrated to reduce mortality due to bleeding (but not the incidence of transfusion) in developing countries. On the other hand, the benefit-risk ratio of TXA has not been fully assessed in developed countries which have much lower PPH-related mortality rates and better access to other management modalities. As a proposed prophylactic agent to prevent PPH, the level of evidence is currently insufficient to recommend the routine use of TXA to prevent blood loss after vaginal and cesarean deliveries. The results of large new multicenter studies assessing the impact of TXA on maternal blood loss-related outcomes after cesarean delivery are awaited. While most studies to date have focused on empirical and one-size-fit-all dosing of TXA, more selective and individualized treatment protocols (possibly guided by functional coagulation assays) are needed to pave the way for safer and more effective use of this inexpensive and widely used medication.

Effects of tranexamic acid on the amount of bleeding following vaginal delivery and its adverse effects: a double-blind placebo controlled randomized clinical trial

INTRODUCTION

Postpartum hemorrhage (PPH) is the most important concern after delivery. Tranexamic acid (TXA), an anti-fibrinolytic agent, has been suggested for prevention and treatment of PPH.

OBJECTIVE

The purpose of the present study was to find the effects of TXA on the amount of bleeding following vaginal delivery and its adverse effects.

MATERIALS AND METHODS

The study was performed as a randomized double blind placebo controlled clinical trial on low risk pregnant women who delivered vaginally. The patients were randomly assigned into two groups. Women in the intervention group received 10 mg/kg infusion of TXA in 100 mL normal saline and the control group received one vial of distilled water (as placebo) in 100 mL normal saline. The primary outcome was amount of bleeding after delivery. The secondary outcomes were decreased in hemoglobin level, need for additional uterotonic agents and need for blood transfusion. All were evaluated 6 h after delivery and compared in the two groups. Participants were followed up to six weeks after delivery for any TXA side effects.

RESULTS

Two hundred and seven women finished the study. There were no significant differences between the two groups in terms of demographic data and risk factors for bleeding. Mean blood loss and need to misoprostol was more in the control group (p=.033 and p=.000, respectively). Hemoglobin level was higher in the TXA group 6 h after delivery. None of the subjects needed blood transfusion, uterine balloon tamponade or emergency hysterectomy. Adverse effects were higher in the TXA group, however, there were no side effects between weeks 3 and 6 in both groups. There were no thromboembolic events during six weeks after delivery.

CONCLUSIONS

Tranexamic acid can reduce the amount of bleeding after vaginal delivery in low risk women without having serious complications. Also, it may decrease the need for additional uterotonic agents. Trial registration number and registry website: IRCT20091023002624N22.

Association of Intravenous Tranexamic Acid With Thromboembolic Events and Mortality: A Systematic Review, Meta-analysis, and Meta-regression

IMPORTANCE

Tranexamic acid (TXA) is an efficient antifibrinolytic agent; however, concerns remain about the potential adverse effects, particularly vascular occlusive events, that may be associated with its use.

OBJECTIVE

To examine the association between intravenous TXA and total thromboembolic events (TEs) and mortality in patients of all ages and of any medical disciplines.

DATA SOURCE

Cochrane Central Register of Controlled Trials and MEDLINE were searched for eligible studies investigating intravenous TXA and postinterventional outcome published between 1976 and 2020.

STUDY SELECTION

Randomized clinical trials comparing intravenous TXA with placebo/no treatment. The electronic database search yielded a total of 782 studies, and 381 were considered for full-text review. Included studies were published in English, German, French, and Spanish. Studies with only oral or topical tranexamic administration were excluded.

DATA EXTRACTION AND SYNTHESIS

Meta-analysis, subgroup and sensitivity analysis, and meta-regression were performed. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

MAIN OUTCOMES AND MEASURES

Vascular occlusive events and mortality.

RESULTS

A total of 216 eligible trials including 125 550 patients were analyzed. Total TEs were found in 1020 (2.1%) in the group receiving TXA and 900 (2.0%) in the control group. This study found no association between TXA and risk for total TEs (risk difference = 0.001; 95% CI, -0.001 to 0.002; P = .49) for venous thrombosis, pulmonary embolism, venous TEs, myocardial infarction or ischemia, and cerebral infarction or ischemia. Sensitivity analysis using the risk ratio as an effect measure with (risk ratio = 1.02; 95% CI, 0.94-1.11; P = .56) and without (risk ratio = 1.03; 95% CI, 0.95-1.12; P = .52) studies with double-zero events revealed robust effect size estimates. Sensitivity analysis with studies judged at low risk for selection bias showed similar results. Administration of TXA was associated with a significant reduction in overall mortality and bleeding mortality but not with nonbleeding mortality. In addition, an increased risk for vascular occlusive events was not found in studies including patients with a history of thromboembolism. Comparison of studies with sample sizes of less than or equal to 99 (risk difference = 0.004; 95% CI, -0.006 to 0.014; P = .40), 100 to 999 (risk difference = 0.004; 95% CI, -0.003 to 0.011; P = .26), and greater than or equal to 1000 (risk difference = -0.001; 95% CI, -0.003 to 0.001; P = .44) showed no association between TXA and incidence of total TEs. Meta-regression of 143 intervention groups showed no association between TXA dosing and risk for venous TEs (risk difference, -0.005; 95% CI, -0.021 to 0.011; P = .53).

CONCLUSIONS AND RELEVANCE

Findings from this systematic review and meta-analysis of 216 studies suggested that intravenous TXA, irrespective of dosing, is not associated with increased risk of any TE. These results help clarify the incidence of adverse events associated with administration of intravenous TXA and suggest that TXA is safe for use with undetermined utility for patients receiving neurological care.

Application of a plasmin generation assay to define pharmacodynamic effects of tranexamic acid in women undergoing cesarean delivery

Essentials Tranexamic acid (TXA) is an antifibrinolytic drug used to reduce bleeding. Assaying plasmin generation (PG) in plasma detects clinically relevant TXA levels in vitro and ex vivo. 3.1-16.2 µg/mL TXA half-maximally inhibits PG in plasma from women undergoing cesarean delivery. PG velocity shows the strongest dose-relationship at low TXA concentrations (≤10 µg/mL). ABSTRACT: Background Tranexamic acid (TXA) is used to reduce bleeding. TXA inhibits plasmin(ogen) binding to fibrin and reduces fibrinolysis. TXA antifibrinolytic activity is typically measured by clot lysis assays; however, effects on plasmin generation (PG) are unclear due to a lack of tools to measure PG in plasma. Aims Develop an assay to measure PG kinetics in human plasma. Determine effects of TXA on PG and compare with fibrinolysis measured by rotational thromboelastometry (ROTEM). Methods We characterized effects of plasminogen, tissue plasminogen activator, fibrinogen, and α2 -antiplasmin on PG in vitro. We also studied effects of TXA on PG in plasma from 30 pregnant women administered intravenous TXA (5, 10, or 15 mg/kg) during cesarean delivery. PG was measured by calibrated fluorescence. PG parameters were compared with TXA measured by mass spectrometry and ROTEM of whole blood. Results The PG assay is specific for plasmin and sensitive to tissue plasminogen activator, fibrin(ogen), and α2 -antiplasmin. Addition of TXA to plasma in vitro dose dependently prolonged the clot lysis time and delayed and reduced PG. For all doses of TXA administered intravenously, the PG assay detected delayed time-to-peak (≤3 hours) and reduced the velocity, peak, and endogenous plasmin potential (≤24 hours) in plasma samples obtained after infusion. The PG time-to-peak, velocity, and peak correlated significantly with TXA concentration and showed less variability than the ROTEM lysis index at 30 minutes or maximum lysis. Conclusions The PG assay detects pharmacologically relevant concentrations of TXA administered in vitro and in vivo, and demonstrates TXA-mediated inhibition of PG in women undergoing cesarean delivery.

Management of massive hemorrhage in pregnant women with placenta previa

Patients with placenta previa are at risk for intra- and postpartum massive blood loss as well as increased risk of placenta accreta, a type of abnormal placental implantation. This condition can lead to serious obstetric complications, including maternal mortality and morbidity. The risk factors for previa include prior cesarean section, multiparity, advanced maternal age, prior placenta previa history, prior uterine surgery, and smoking. The prevalence of previa parturients has increased due to the rising rates of cesarean section and advanced maternal age. For these reasons, we need to identify the risk factors for previa and identify adequate management strategies to respond to blood loss during surgery. This review evaluated the diagnosis of placenta previa and placenta accreta and assessed the risk factors for previa-associated bleeding prior to cesarean section. We then presented intraoperative anesthetic management and other interventions to control bleeding in patients with previa expected to experience massive hemorrhage and require transfusion.

TRAAP2 - TRAnexamic Acid for Preventing postpartum hemorrhage after cesarean delivery: a multicenter randomized, doubleblind, placebo- controlled trial - a study protocol

Background

An antifibrinolytic agent that blocks lysine-binding sites on plasminogen molecules, tranexamic acid reduces bleeding-related mortality in women with postpartum hemorrhage (PPH), especially administered fairly soon after delivery. According to the randomized controlled trials thus far reported for PPH prevention after cesarean deliveries (n = 16), women who received tranexamic acid had significantly less postpartum blood loss and no increase in severe adverse effects. These were, however, primarily small single-center studies that had fundamental methodological flaws. Multicenter randomized controlled trials with adequate power are necessary to demonstrate its value persuasively before tranexamic acid goes into widespread use for the prevention of PPH after cesarean deliveries.

Methods/design

This study will be a multicenter, double-blind, randomized controlled trial with two parallel groups including 4524 women with cesarean deliveries before or during labor, at a term ≥34 weeks, modeled on our previous study of tranexamic acid administered after vaginal deliveries. Treatment (either tranexamic acid 1 g or placebo) will be administered intravenously just after birth. All women will also receive a prophylactic uterotonic agent. The primary outcome will be the incidence of PPH, defined by a calculated estimated blood loss > 1000 mL or a red blood cell transfusion before day 2 postpartum. This study will have 80% power to show a 20% reduction in the incidence of PPH, from 15.0 to 12.0%.

Discussion

As an, inexpensive, easy to administer drug that can be add to the routine management of cesarean births in delivery rooms, tranexamic acid is a promising candidate for preventing PPH after these births. This large, adequately powered, multicenter randomized placebo-controlled trial seeks to determine if the benefits of the routine prophylactic use of tranexamic acid after cesarean delivery significantly outweigh its risks.

Trial registration

ClinicalTrials.gov NCT03431805 (February 12, 2018).

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.

Uterotonic agents for preventing postpartum haemorrhage: a network meta-analysis

BACKGROUND

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Prophylactic uterotonic agents can prevent PPH, and are routinely recommended. The current World Health Organization (WHO) recommendation for preventing PPH is 10 IU (international units) of intramuscular or intravenous oxytocin. There are several uterotonic agents for preventing PPH but there is still uncertainty about which agent is most effective with the least side effects. This is an update of a Cochrane Review which was first published in April 2018 and was updated to incorporate results from a recent large WHO trial.

OBJECTIVES

To identify the most effective uterotonic agent(s) to prevent PPH with the least side effects, and generate a ranking according to their effectiveness and side-effect profile.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (24 May 2018), and reference lists of retrieved studies.

SELECTION CRITERIA

All randomised controlled trials or cluster-randomised trials comparing the effectiveness and side effects of uterotonic agents with other uterotonic agents, placebo or no treatment for preventing PPH were eligible for inclusion. Quasi-randomised trials were excluded. Randomised trials published only as abstracts were eligible if sufficient information could be retrieved.

DATA COLLECTION AND ANALYSIS

At least three review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We estimated the relative effects and rankings for preventing PPH ≥ 500 mL and PPH ≥ 1000 mL as primary outcomes. Secondary outcomes included blood loss and related outcomes, morbidity outcomes, maternal well-being and satisfaction and side effects. Primary outcomes were also reported for pre-specified subgroups, stratifying by mode of birth, prior risk of PPH, healthcare setting, dosage, regimen and route of administration. We performed pairwise meta-analyses and network meta-analysis to determine the relative effects and rankings of all available agents.

MAIN RESULTS

The network meta-analysis included 196 trials (135,559 women) involving seven uterotonic agents and placebo or no treatment, conducted across 53 countries (including high-, middle- and low-income countries). Most trials were performed in a hospital setting (187/196, 95.4%) with women undergoing a vaginal birth (71.5%, 140/196).Relative effects from the network meta-analysis suggested that all agents were effective for preventing PPH ≥ 500 mL when compared with placebo or no treatment. The three highest ranked uterotonic agents for prevention of PPH ≥ 500 mL were ergometrine plus oxytocin combination, misoprostol plus oxytocin combination and carbetocin. There is evidence that ergometrine plus oxytocin (RR 0.70, 95% CI 0.59 to 0.84, moderate certainty), carbetocin (RR 0.72, 95% CI 0.56 to 0.93, moderate certainty) and misoprostol plus oxytocin (RR 0.70, 95% CI 0.58 to 0.86, low certainty) may reduce PPH ≥ 500 mL compared with oxytocin. Low-certainty evidence suggests that misoprostol, injectable prostaglandins, and ergometrine may make little or no difference to this outcome compared with oxytocin.All agents except ergometrine and injectable prostaglandins were effective for preventing PPH ≥ 1000 mL when compared with placebo or no treatment. High-certainty evidence suggests that ergometrine plus oxytocin (RR 0.83, 95% CI 0.66 to 1.03) and misoprostol plus oxytocin (RR 0.88, 95% CI 0.70 to 1.11) make little or no difference in the outcome of PPH ≥ 1000 mL compared with oxytocin. Low-certainty evidence suggests that ergometrine may make little or no difference to this outcome compared with oxytocin meanwhile the evidence on carbetocin was of very low certainty. High-certainty evidence suggests that misoprostol is less effective in preventing PPH ≥ 1000 mL when compared with oxytocin (RR 1.19, 95% CI 1.01 to 1.42). Despite the comparable relative treatment effects between all uterotonics (except misoprostol) and oxytocin, ergometrine plus oxytocin, misoprostol plus oxytocin combinations and carbetocin were the highest ranked agents for PPH ≥ 1000 mL.Misoprostol plus oxytocin reduces the use of additional uterotonics (RR 0.56, 95% CI 0.42 to 0.73, high certainty) and probably also reduces the risk of blood transfusion (RR 0.51, 95% CI 0.37 to 0.70, moderate certainty) when compared with oxytocin. Carbetocin, injectable prostaglandins and ergometrine plus oxytocin may also reduce the use of additional uterotonics but the certainty of the evidence is low. No meaningful differences could be detected between all agents for maternal deaths or severe morbidity as these outcomes were rare in the included randomised trials where they were reported.The two combination regimens were associated with important side effects. When compared with oxytocin, misoprostol plus oxytocin combination increases the likelihood of vomiting (RR 2.11, 95% CI 1.39 to 3.18, high certainty) and fever (RR 3.14, 95% CI 2.20 to 4.49, moderate certainty). Ergometrine plus oxytocin increases the likelihood of vomiting (RR 2.93, 95% CI 2.08 to 4.13, moderate certainty) and may make little or no difference to the risk of hypertension, however absolute effects varied considerably and the certainty of the evidence was low for this outcome.Subgroup analyses did not reveal important subgroup differences by mode of birth (caesarean versus vaginal birth), setting (hospital versus community), risk of PPH (high versus low risk for PPH), dose of misoprostol (≥ 600 mcg versus < 600 mcg) and regimen of oxytocin (bolus versus bolus plus infusion versus infusion only).

AUTHORS' CONCLUSIONS

All agents were generally effective for preventing PPH when compared with placebo or no treatment. Ergometrine plus oxytocin combination, carbetocin, and misoprostol plus oxytocin combination may have some additional desirable effects compared with the current standard oxytocin. The two combination regimens, however, are associated with significant side effects. Carbetocin may be more effective than oxytocin for some outcomes without an increase in side effects.

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.

Active management of the third stage of labor: A brief overview of key issues

Postpartum hemorrhage is a potentially life-threatening, albeit preventable, condition that persists as a leading cause of maternal death. It occurs mostly during the third stage of labor, and active management of the third stage of labor (AMTSL) can prevent its occurrence. AMTSL is a recommended series of steps, including the provision of uterotonic drugs immediately upon fetal delivery, controlled cord traction, and massage of the uterine fundus, as developed by the World Health Organization. Here, we present current opinion and protocols for AMTSL.

Postpartum haemorrhage related early increase in D-dimers is inhibited by tranexamic acid: haemostasis parameters of a randomized controlled open labelled trial

BACKGROUND

Beneficial effects of tranexamic acid (TA) have been established in surgery and trauma. In ongoing postpartum haemorrhage (PPH), a moderate reduction of blood loss was observed in a previously published randomized controlled trial. Analysis of haemostasis parameters obtained from samples collected as part of this study are presented.

METHODS

Women with PPH >800 ml after vaginal delivery were assigned to receive either TA (4 g over 1 h, then 1 g per h over six h) (TA) or not (H). A non-haemorrhagic group (NH), <800 ml blood loss, was included as postpartum reference. At four time-points (enrolment, +30 min, +2 h, +6 h), haemostasis was assessed. Haemostasis assays were performed blinded to group allocation. Data were expressed as median [interquartiles] and compared with non-parametric tests.

RESULTS

In H compared with NH group, D-dimers increase (3730 ng ml(-1) [2468-8493] vs 2649 [2667-4375]; P=0.0001) and fibrinogen and factor II decrease were observed at enrolment and became maximal 2 h later. When comparing TA to H patients, the increase in Plasmin-Antiplasmin-complexes at +30 min (486 ng ml(-1) [340-1116] vs 674 [548-1640]; P=0.03) and D-dimers at +2 h (3888 ng ml(-1) [2688-6172] vs 7495 [4400-15772]; P=0.0001) was blunted. TA had no effect on fibrinogen decrease.

CONCLUSIONS

This study provides biological evidence of an early increase in D-dimers and plasmin-antiplasmin complexes associated with active post-partum haemorrhage and its attenuation by the early use of a clinically effective high dose of TA, opening the perspective of dose ranging studies to determinate the optimal dose and timing in this setting.

CLINICAL TRIAL REGISTRATION

ISRCTN09968140.

Peripartum Haemorrhage, Diagnosis and Therapy. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Registry No. 015/063, March 2016)

Purpose

This is an official interdisciplinary guideline, published and coordinated by the German Society of Gynaecology and Obstetrics (DGGG), the Austrian Society of Gynaecology and Obstetrics (OEGGG) and the Swiss Society of Gynaecology and Obstetrics (SGGG). The guideline was developed for use in German-speaking countries and is backed by the German Society of Anaesthesiology and Intensive Medicine (DGAI), the Society of Thrombosis and Haemostasis Research (GTH) and the German Association of Midwives. The aim is to provide a consensus-based overview of the diagnosis and management of peripartum bleeding obtained from an evaluation of the relevant literature.

Methods

This S2k guideline was developed from the structured consensus of representative members of the various professional associations and professions commissioned by the Guideline Commission of the DGGG.

Recommendations

The guideline encompasses recommendations on definitions, risk stratification, prevention and management.

Uterotonic agents for preventing postpartum haemorrhage: a network meta-analysis

BACKGROUND

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Prophylactic uterotonic drugs can prevent PPH, and are routinely recommended. There are several uterotonic drugs for preventing PPH but it is still debatable which drug is best.

OBJECTIVES

To identify the most effective uterotonic drug(s) to prevent PPH, and generate a ranking according to their effectiveness and side-effect profile.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (1 June 2015), ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) for unpublished trial reports (30 June 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

All randomised controlled comparisons or cluster trials of effectiveness or side-effects of uterotonic drugs for preventing PPH.Quasi-randomised trials and cross-over trials are not eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

At least three review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We estimated the relative effects and rankings for preventing PPH ≥ 500 mL and PPH ≥ 1000 mL as primary outcomes. We performed pairwise meta-analyses and network meta-analysis to determine the relative effects and rankings of all available drugs. We stratified our primary outcomes according to mode of birth, prior risk of PPH, healthcare setting, dosage, regimen and route of drug administration, to detect subgroup effects.The absolute risks in the oxytocin are based on meta-analyses of proportions from the studies included in this review and the risks in the intervention groups were based on the assumed risk in the oxytocin group and the relative effects of the interventions.

MAIN RESULTS

This network meta-analysis included 140 randomised trials with data from 88,947 women. There are two large ongoing studies. The trials were mostly carried out in hospital settings and recruited women who were predominantly more than 37 weeks of gestation having a vaginal birth. The majority of trials were assessed to have uncertain risk of bias due to poor reporting of study design. This primarily impacted on our confidence in comparisons involving carbetocin trials more than other uterotonics.The three most effective drugs for prevention of PPH ≥ 500 mL were ergometrine plus oxytocin combination, carbetocin, and misoprostol plus oxytocin combination. These three options were more effective at preventing PPH ≥ 500 mL compared with oxytocin, the drug currently recommended by the WHO (ergometrine plus oxytocin risk ratio (RR) 0.69 (95% confidence interval (CI) 0.57 to 0.83), moderate-quality evidence; carbetocin RR 0.72 (95% CI 0.52 to 1.00), very low-quality evidence; misoprostol plus oxytocin RR 0.73 (95% CI 0.60 to 0.90), moderate-quality evidence). Based on these results, about 10.5% women given oxytocin would experience a PPH of ≥ 500 mL compared with 7.2% given ergometrine plus oxytocin combination, 7.6% given carbetocin, and 7.7% given misoprostol plus oxytocin. Oxytocin was ranked fourth with close to 0% cumulative probability of being ranked in the top three for PPH ≥ 500 mL.The outcomes and rankings for the outcome of PPH ≥ 1000 mL were similar to those of PPH ≥ 500 mL. with the evidence for ergometrine plus oxytocin combination being more effective than oxytocin (RR 0.77 (95% CI 0.61 to 0.95), high-quality evidence) being more certain than that for carbetocin (RR 0.70 (95% CI 0.38 to 1.28), low-quality evidence), or misoprostol plus oxytocin combination (RR 0.90 (95% CI 0.72 to 1.14), moderate-quality evidence)There were no meaningful differences between all drugs for maternal deaths or severe morbidity as these outcomes were so rare in the included randomised trials.Two combination regimens had the poorest rankings for side-effects. Specifically, the ergometrine plus oxytocin combination had the higher risk for vomiting (RR 3.10 (95% CI 2.11 to 4.56), high-quality evidence; 1.9% versus 0.6%) and hypertension [RR 1.77 (95% CI 0.55 to 5.66), low-quality evidence; 1.2% versus 0.7%), while the misoprostol plus oxytocin combination had the higher risk for fever (RR 3.18 (95% CI 2.22 to 4.55), moderate-quality evidence; 11.4% versus 3.6%) when compared with oxytocin. Carbetocin had similar risk for side-effects compared with oxytocin although the quality evidence was very low for vomiting and for fever, and was low for hypertension.

AUTHORS' CONCLUSIONS

Ergometrine plus oxytocin combination, carbetocin, and misoprostol plus oxytocin combination were more effective for preventing PPH ≥ 500 mL than the current standard oxytocin. Ergometrine plus oxytocin combination was more effective for preventing PPH ≥ 1000 mL than oxytocin. Misoprostol plus oxytocin combination evidence is less consistent and may relate to different routes and doses of misoprostol used in the studies. Carbetocin had the most favourable side-effect profile amongst the top three options; however, most carbetocin trials were small and at high risk of bias.Amongst the 11 ongoing studies listed in this review there are two key studies that will inform a future update of this review. The first is a WHO-led multi-centre study comparing the effectiveness of a room temperature stable carbetocin versus oxytocin (administered intramuscularly) for preventing PPH in women having a vaginal birth. The trial includes around 30,000 women from 10 countries. The other is a UK-based trial recruiting more than 6000 women to a three-arm trial comparing carbetocin, oxytocin and ergometrine plus oxytocin combination. Both trials are expected to report in 2018.Consultation with our consumer group demonstrated the need for more research into PPH outcomes identified as priorities for women and their families, such as women's views regarding the drugs used, clinical signs of excessive blood loss, neonatal unit admissions and breastfeeding at discharge. To date, trials have rarely investigated these outcomes. Consumers also considered the side-effects of uterotonic drugs to be important but these were often not reported. A forthcoming set of core outcomes relating to PPH will identify outcomes to prioritise in trial reporting and will inform futures updates of this review. We urge all trialists to consider measuring these outcomes for each drug in all future randomised trials. Lastly, future evidence synthesis research could compare the effects of different dosages and routes of administration for the most effective drugs.

Safety and efficacy of tranexamic acid for prevention of obstetric haemorrhage: an updated systematic review and meta-analysis

BACKGROUND

A number of clinical systematic review and meta-analysis have been published on the use of tranexamic in the obstetric setting. The aim of this meta-analysis was to evaluate the safety and effectiveness of tranexamic acid in reducing blood loss when given prior to caesarean delivery.

MATERIALS AND METHODS

We searched the Cochrane Wounds Specialized Register, Cochrane Central, MEDLINE (through PUBMED), Embase, and SCOPUS electronic databases. We also searched clinical trials registries for ongoing and unpublished studies, and checked reference lists to identify additional studies. We used no restrictions with respect to language and date of publication. Two review authors independently performed study selection, "Risk of bias" assessment, and data extraction. Initial disagreements were resolved by discussion, or by including a third review author when necessary.

RESULTS

We found 18 randomised controlled trials (RCTs) that met our inclusion criteria. Overall, 1,764 women receiving intravenous tranexamic acid for prevention of bleeding following caesarean sections and 1,793 controls receiving placebo were enrolled in the 18 RCTs evaluated. The use of tranexamic acid compared to controls (placebo or no intervention) reduces post-partum haemorrhage >400 mL (risk ratio [RR] 0.40, 95% confidence interval [CI] 0.24-0.65; 5 trials with a total of 786 participants), severe post-partum haemorrhage >1,000 mL (RR 0.32, 95% CI: 0.12-0.84; 5 trials with a total of 1,850 participants), and need for red blood cell transfusion (RR 0.30, 95% CI: 0.18-0.49; 10 trials with a total of 1,873 participants). No particular safety concerns on the use of this antifibrinolytic agent emerged from the analysis of the 18 RCTs included.

DISCUSSION

Overall, the results of this meta-analysis support the evidence of a beneficial effect of tranexamic acid in reducing blood loss and need for blood transfusion in pregnant women undergoing caesarean section.

Therapeutic and pharmaco-biological, dose-ranging multicentre trial to determine the optimal dose of TRAnexamic acid to reduce blood loss in haemorrhagic CESarean delivery (TRACES): study protocol for a randomised, double-blind, placebo-controlled trial

Background

Postpartum haemorrhage (PPH) is the leading cause of maternal death worldwide. Tranexamic acid (TA), an antifibrinolytic drug, reduces bleeding and transfusion need in major surgery and trauma. In ongoing PPH following vaginal delivery, a high dose of TA decreases PPH volume and duration, as well as maternal morbidity, while early fibrinolysis is inhibited. In a large international trial, a TA single dose reduced mortality due to bleeding but not the hysterectomy rate. TA therapeutic dosages vary from 2.5 to 100 mg/kg and seizures, visual disturbances and nausea are observed with the highest dosages. TA efficiency and optimal dosage in haemorrhagic caesarean section (CS) has not been yet determined. We hypothesise large variations in fibrinolytic activity during haemorrhagic caesarean section needing targeted TA doses for clinical and biological efficacy.

Methods/design

The current study proposal is a blinded, randomised controlled trial with the primary objective of determining superiority of either 1 g of TXA or 0.5 g of TXA, in comparison to placebo, in terms of 30% blood-loss reduction at 6 h after non-emergency haemorrhagic caesarean delivery (active PPH > 800 mL) and to correlate this clinical effect in a pharmacokinetics model with fibrinolysis inhibition measured by an innovative direct plasmin measurement regarding plasmatic TA concentration.

A sample size of 342 subjects (114 per group) was calculated, based on the expected difference of 30% reduction of blood loss between the placebo group and the low-dose group, out of which 144 patients will be included blindly in the pharmaco-biological substudy. A non-haemorrhagic reference group will include 48 patients in order to give a reference for peak plasmin level.

Discussion

TRACES trial is expected to give the first pharmacokinetics data to determinate the optimal dose of tranexamic acid to reduce blood loss and inhibit fibrinolysis in hemorrhagic cesarean section.

Trial registration

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

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2420-7) contains supplementary material, which is available to authorized users.

Tranexamic acid for treatment and prophylaxis of bleeding and hyperfibrinolysis

Uncontrolled massive bleeding with subsequent derangement of the coagulation system is a major challenge in the management of both surgical and seriously injured patients. Under physiological conditions activators and inhibitors of coagulation regulate the sensitive balance between clot formation and fibrinolysis. In some cases, excessive and diffuse bleeding is caused by systemic activation of fibrinolysis, i. e. hyperfibrinolysis (HF). Uncontrolled HF is associated with a high mortality. Polytrauma patients and those undergoing surgical procedures involving organs rich in plasminogen proactivators (e. g. liver, kidney, pancreas, uterus and prostate gland) are at a high risk for HF. Antifibrinolytics, such as tranexamic acid (TXA) are used for prophylaxis and treatment of bleeding caused by a local or generalized HF as well as other hemorrhagic conditions. TXA is a synthetic lysine analogue that has been available in Austria since 1966. TXA is of utmost importance in the prevention and treatment of traumatic and perioperative bleeding due to the resulting reduction in perioperative blood loss and blood transfusion requirements. The following article presents the different fields of application of TXA with particular respect to indications and dosages, based on a literature search and on current guidelines.

Identification and Management of Obstetric Hemorrhage

Obstetric hemorrhage remains the leading cause of maternal death and severe morbidity worldwide. Although uterine atony is the most common cause of peripartum bleeding, abnormal placentation, coagulation disorders, and genital tract trauma contribute to adverse maternal outcomes. Given the inability to reliably predict patients at high risk for obstetric hemorrhage, all parturients should be considered susceptible, and extreme vigilance must be exercised in the assessment of blood loss and hemodynamic stability during the peripartum period. Obstetric-specific hemorrhage protocols, facilitating the integration and timely escalation of pharmacologic, radiological, surgical, and transfusion interventions, are critical to the successful management of peripartum bleeding.

Is prophylactic tranexamic acid administration effective and safe for postpartum hemorrhage prevention?: A systematic review and meta-analysis

BACKGROUND

To assess the efficacy and safety of tranexamic acid (TA) in reducing blood loss and lowering transfusion needs for patients undergoing caesarean section (CS) or vaginal delivery (VD).

METHODS

An electronic literature search of PubMed, EMBASE, OVID, Cochrane library, Scopus, Central, and Clinical trials.gov was performed to identify studies that evaluating the usage of TA in CS or VD. The methodological quality of included trials was assessed and data extraction was performed.

RESULTS

Finally, 25 articles with 4747 participants were included. Our findings indicated TA resulted in a reduced intra-, postoperative, and total blood loss by a mean volume of 141.25 mL (95% confidence interval [CI] -186.72 to -95.79, P < 0.00001), 36.42 mL (95% CI -46.50 to -26.34, P < 0.00001), and 154.25 mL (95% CI -182.04 to -126.47, P < 0.00001) in CS. TA administration in VD was associated with a reduced intra-, postoperative, and total blood loss by a mean volume of 22.88 mL (95% CI -50.54 to 4.77, P = 0.10), 41.24 mL (95% CI -55.50 to -26.98, P < 0.00001), and 84.79 mL (95% CI -109.93 to -59.65, P < 0.00001). In addition, TA could lower the occurrence rate of postpartum hemorrhage (PPH) and severe PPH, and reduce the risk of blood transfusions. No increased risk of deep vein thrombosis (DVT) after CS or VD was associated with TA usage, while the minor side effects were more common.

CONCLUSIONS

Our findings indicated that intravenous TA for patients undergoing CS was effective and safe. Although prophylactic TA administration is associated with reduced PPH, current existing data are insufficient to draw definitive recommendations about its clinical significance due to the poor to moderate quality of the included literatures. Thus, high-quality randomized controlled trials with larger samples are needed to validate our findings.

Role of Prophylactic Tranexamic Acid in Reducing Blood Loss during Elective Caesarean Section: A Randomized Controlled Study

INTRODUCTION

Obstetric haemorrhage accounts for 20-25% of maternal mortality and morbidity. Anti-fibrinolytics are being widely used in field of surgery. It is also used to reduce heavy menstrual blood loss.

AIM

To analyse the effectiveness of Tranexamic Acid (TXA) in reducing blood loss during elective caesarean section.

MATERIALS AND METHODS

This interventional, randomized, parallel group study was done in the Department of Obstetrics and Gynaecolgy, PSG IMSR, Coimbatore, from June 2014 to May 2015. It was conducted on 120 women undergoing caesarean section. They were allocated to either Study or Control group by computer generated random number tables. TXA was given prior to surgery in study group in addition to the routine care {10 units of oxytocin added to the intravenous drip soon after baby delivery} whereas, the control group had routine care alone. Blood loss was measured in both groups by gravimetric method. Haemoglobin before and after surgery was estimated and the percentage of difference was compared.

STATISTICAL ANALYSIS

Primary outcome variables were volume of blood loss and percentage fall in haemoglobin before and after surgery. Secondary outcomes were duration of surgery, proportion of subjects with >500ml of blood loss, need for additional uterotonics and side effects. Unpaired t-test and Chi-square test were used to compare the outcome variables.

RESULTS

There was significant reduction in blood loss calculated from placental delivery till end of surgery: 347.17ml in study group versus 517.72ml in control group (p<0.001). Another parameter studied was the percentage of fall in haemoglobin before and after surgery and the number of subjects who had more than 10% fall in haemoglobin. 9.3% of subjects in study group and 39% of subjects in control group had more than 10% fall in haemoglobin (p<0.01). There were no immediate post-operative complications to the mother and neonate.

CONCLUSION

TXA significantly reduced the amount of blood loss during Lower Segment Caesarean Section (LSCS). Use of TXA was not associated with adverse effects. Thus, TXA can be used safely and effectively in subjects undergoing LSCS.

Role of Tranexamic Acid in Reducing Blood Loss in Vaginal Delivery

INTRODUCTION

Anti-fibrinolytic agents are used to reduce obstetric blood loss as the fibrinolytic system is known to get activated after placental delivery.

OBJECTIVES

To evaluate the efficacy of parenteral tranexamic acid in reducing blood loss during normal labour and to compare it with the amount of blood loss in patients who received placebo in the third stage of labour.

METHODOLOGY

Patients with spontaneous labour or planned for induction of labour and fulfilling the inclusion criteria were recruited for the study. In each patient, the pre-delivery pulse rate, blood pressure, Hb gm% and PCV% were noted. Labour was monitored carefully using a partogram. The study group received Inj. Oxytocin and Inj. Tranexamic acid. The control group received Inj. Oxytocin and Placebo injection. Immediately after delivery of the baby, when all the liquor was drained, the patient was placed over a blood drape-a disposable conical, graduated plastic collection bag. The amount of blood collected in the blood drape was measured. Then the patient was given pre-weighed pads, which were weighed 2 h post-partum. The blood loss was measured by measuring the blood collected in the drape and by weighing the swabs before and after delivery.

RESULTS

The total number of patients studied was 100-equally distributed in both the groups. The age group of the patients and BMI were comparable. There was a significant increase in the pulse rate and decrease in blood pressure in the control group as compared with the study group. The post-delivery haemoglobin and haematocrit were significantly reduced in the control group as compared to the study group. The mean blood loss at the end of 2 h was 105 ml in the study group and 252 ml in the control group. There was a significant increase in the usage of uterotonics and also in the need for blood transfusion in the control group; 12 % of the patients in the control group had to stay for more than 3 days compared to 2 % in the study group.

CONCLUSION

Tranexamic acid injection, an antifibrinolytic agent when given prophylactically after the delivery of the baby, by intravenous route appears to reduce the blood loss and maternal morbidity during normal labour effectively.

Role of Intravenous Tranexamic Acid on Caesarean Blood Loss: A Prospective Randomised Study

BACKGROUND

Post-partum haemorrhage (PPH) is a major cause of maternal mortality globally. Tranexamic acid, an anti-fibrinolytic agent, is a novel approach in an attempt to prevent this dreadful complication. This study aims to document the efficacy of intravenous (IV) tranexamic acid in reducing blood loss during and after caesarean section (CS).

METHODS

In this prospective randomised placebo-controlled open-label study, 100 mothers scheduled for elective CS were randomly selected and divided into two groups (study and control) of 50 each. The study group received 1 g IV tranexamic acid and the control group received IV placebo. Following delivery, all mothers received ten units of oxytocin in 500 ml of normal saline.

RESULTS

The mean intra-operative and post-partum blood loss were significantly lower in the study group than the control group: 499.11 ± 111.2 and 59.93 ± 12.5 ml versus 690.85 ± 198.41 and 110.06 ± 13.47 ml, respectively, (p < 0.001). Total blood loss was 30 % less in the study group (p < 0.001). Six mothers had PPH in the control group, while none in the study group. The difference between the pre-operative and post-operative haemoglobin levels was significantly less in the study group than the control group, 0.26 ± 0.22 versus 0.99 ± 0.48 g% (p < 0.001).There was no significant difference with respect to other haematological parameters. There was no added adverse effect or need for NICU admission in the study group.

CONCLUSION

Pre-operative IV tranexamic acid significantly reduced blood loss during elective CS without any significant adverse effects.

Tranexamic acid and blood loss during and after cesarean section: a meta-analysis

OBJECTIVE

A meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate whether tranexamic acid (TXA) could significantly reduce blood loss during and after cesarean section (CS) when compared with no TXA.

STUDY DESIGN

MEDLINE (PubMed), EMBASE, Cochrane Central Register of Controlled Trials and Web of Science were searched to identify RCTs that compared intravenous TXA with no TXA before CS for blood loss. The related data were extracted by two independent authors. The fixed or random-effect methods were used to combine data.

RESULT

Eleven RCTs were included in this analysis with a total of 1276 women in TXA group and 1255 in no TXA (control) group. Total blood loss during and after CS was significantly less in TXA group than in control group (mean difference (MD) -141.61 ml, 95% confidence interval (CI) -207.09 to -76.14, P<0.01). There was a significant reduction in intraoperative and postpartum blood loss in TXA group as compared with control group (MD -143.36 ml, 95% CI -220.38 to -66.35, P<0.01; and MD -38.20 ml, 95% CI -59.27 to -17.12, P<0.01, respectively). Declines in hemoglobin and hematocrit values after CS were both significantly less in TXA group than in control group. The difference of postpartum hemorrhage rate was statistically significant between groups (risk ratio (RR) 0.57, 95% CI 0.37 to 0.89, P=0.01). The need for blood transfusion was significantly less in TXA group than control group (RR 0.23, 95% CI 0.10 to 0.57, P<0.01).

CONCLUSION

Our results demonstrate that TXA offers an advantage over no TXA in reducing blood loss during and after CS.

Prophylactic Use of Tranexamic Acid for Postpartum Bleeding Outcomes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Despite multimodal approaches to treatment, postpartum hemorrhage (PPH) is a life-threatening condition whose incidence continues to rise. In developing areas, such as sub-Saharan Africa, PPH is the leading cause of maternal mortality. Tranexamic acid (TXA) is a possible prophylactic treatment for the prevention of PPH. We performed a systematic review and meta-analysis of randomized trials comparing prophylactic TXA vs placebo or no treatment in term parturients to quantify the effects of prophylactic TXA administration on peripartum bleeding outcomes. The meta-analysis was performed using a random-effects model. The outcomes assessed were (i) incidence of PPH, (ii) mean blood loss (in milliliters) within 24hours, (iii) incidence of red blood cell transfusion within 24hours, (iv) use of additional uterotonics, (v) minor side effects (ie, nausea, vomiting, headache, etc), (vi) major venous thromboembolism, (vii) length of hospital stay, and (viii) mortality. Eighteen trials (3846 subjects) were included in the quantitative analysis, with 1935 patients receiving TXA. The studies were of poor to moderate quality. Prophylactic TXA administration was associated with a decreased incidence of PPH after delivery (odds ratio [OR], 0.32; 95% confidence interval [CI], 0.17-0.59; P = .0006), a reduction in mean blood loss by 149.1mL (95% CI, 112.9-185.2; P < .00001), and a reduction in red blood cell transfusions (OR, 0.28; 95% CI, 0.15-0.49; P < .00001) while also being associated with a reduction in the use of additional uterotonics (OR, 0.45; 95% CI, 0.30-0.66; P < .00001). Minor side effects were more common in those who received TXA (OR, 2.51; 95% CI, 1.69-3.74; P < .00001). There appeared to be no increased risk of venous thromboembolism and no difference in length of hospital stay associated with TXA use. Although prophylactic TXA administration may be associated with improved peripartum bleeding, existing evidence is insufficient for any definitive recommendations secondary to the poor to moderate quality of the literature. A large well-designed, methodologically sound, randomized controlled trial is needed to better delineate the true effect size and address potential safety concerns.

Tranexamic acid for preventing postpartum haemorrhage

BACKGROUND

Postpartum haemorrhage (PPH) is a common and potentially life-threatening complication of labour. Several options for preventing PPH are available, but further advances in this field are important, especially the identification of safe, easy to use and cost-effective regimens. Tranexamic acid (TA), which is an antifibrinolytic agent that is used widely to prevent and treat haemorrhage, merits evaluation to assess whether it meets these criteria.

OBJECTIVES

To determine, from the best available evidence, whether TA is effective and safe for preventing PPH in comparison to placebo or no treatment (with or without uterotonic co-treatment), or to uterotonic agents.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 January 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

All published, unpublished and ongoing randomised controlled trials (RCTs) evaluating the use of TA alone or in addition to uterotonics in the third stage of labour or during caesarean section (CS) to prevent PPH.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed for inclusion all the potential studies identified as a result of the search strategy. We entered the data into Review Manager software and checked for accuracy.

MAIN RESULTS

Twelve trials involving 3285 healthy women at low risk of excessive bleeding undergoing elective CS (nine trials, 2453 participants) or spontaneous birth (three trials, 832 participants) satisfied inclusion criteria and contributed data to the analysis. All participants received routine prophylactic uterotonics in accordance with the local guideline in addition to TA or placebo or no intervention. Overall, included studies had moderate risk of bias for random sequence generation, allocation concealment, blinding, selective reporting and low risk of bias for incomplete data. The quality of evidence was also as assessed using GRADE.Blood loss greater than 400 mL or 500 mL, and more than 1000 mL was less common in women who received TA versus placebo or no intervention (risk ratio (RR) 0.52, 95% confidence interval (CI) 0.42 to 0.63, six trials, 1398 women; moderate quality evidence) and (RR 0.40, 95% CI 0.23 to 0.71, six trials, 2093 women; moderate quality evidence), respectively. TA was effective in decreasing the incidence of blood loss greater than 1000 mL in women who had undergone CS (RR 0.43, 95% CI 0.23, 0.78, four trials, 1534 women), but not vaginal birth (RR 0.28, 95% CI 0.06, 1.36, two trials 559 women). The effect of TA on blood loss greater than 500 mL or 400 mL was more pronounced in the group of women having vaginal birth than in women who had CS. Mean blood loss (from delivery until two hours postpartum) was lower in women who received TA versus placebo or no intervention (mean difference MD - 77.79 mL, 95% CI -97.95, -57.64, five trials, 1186 women) and this effect was similar following vaginal birth and CS.Additional medical interventions (moderate quality evidence) and blood transfusions were less frequent in women receiving TA versus placebo or no interventions. Mild side effects such as nausea, vomiting, dizziness were more common with the use of TA (moderate quality evidence). The effect of TA on maternal mortality, severe morbidity and thromboembolic events is uncertain (low quality evidence).

AUTHORS' CONCLUSIONS

TA (in addition to uterotonic medications) decreases postpartum blood loss and prevents PPH and blood transfusions following vaginal birth and CS in women at low risk of PPH based on studies of mixed quality. There is insufficient evidence to draw conclusions about serious side effects, but there is an increase in the incidence of minor side effects with the use of TA. Effects of TA on thromboembolic events and mortality as well as its use in high-risk women should be investigated further.

Study protocol. TRAAP - TRAnexamic Acid for Preventing postpartum hemorrhage after vaginal delivery: a multicenter randomized, double-blind, placebo-controlled trial

Background

Postpartum hemorrhage (PPH) is a major cause of maternal mortality, accounting for one quarter of all maternal deaths worldwide. Estimates of its incidence in the literature vary widely, from 3 % to 15 % of deliveries. Uterotonics after birth are the only intervention that has been shown to be effective in preventing PPH. Tranexamic acid (TXA), an antifibrinolytic agent, has been investigated as a potentially useful complement to uterotonics for prevention because it has been proved to reduce blood loss in elective surgery, bleeding in trauma patients, and menstrual blood loss. Randomized controlled trials for PPH prevention after cesarean (n = 10) and vaginal (n = 2) deliveries show that women who received TXA had significantly less postpartum blood loss without any increase in their rate of severe adverse effects. However, the quality of these trials was poor and they were not designed to test the effect of TXA on the reduction of PPH incidence. Large, adequately powered, multicenter randomized controlled trials are required before the widespread use of TXA to prevent PPH can be recommended.

Methods and design

A multicenter, double-blind, randomized controlled trial will be performed. It will involve 4000 women in labor for a planned vaginal singleton delivery, at a term ≥ 35 weeks. Treatment (either TXA 1 g or placebo) will be administered intravenously just after birth. Prophylactic oxytocin will be administered to all women. The primary outcome will be the incidence of PPH, defined by blood loss ≥500 mL, measured with a graduated collector bag. This study will have 80 % power to show a 30 % reduction in the incidence of PPH, from 10.0 % to 7.0 %.

Discussion

In addition to prophylactic uterotonic administration, a complementary component of the management of third stage of labor acting on the coagulation process may be useful in preventing PPH. TXA is a promising candidate drug, inexpensive, easy to administer, and simple to add to the routine management of deliveries in hospitals. This large, adequately powered, multicenter, randomized placebo-controlled trial seeks to determine if the risk-benefit ratio favors the routine use of TXA after delivery to prevent PPH.

Trial registration

ClinicalTrials.gov NCT02302456 (November 17, 2014)

Hemostatic resuscitation in postpartum hemorrhage - a supplement to surgery

BACKGROUND

Postpartum hemorrhage is a potentially life-threatening albeit preventable condition that persists as a leading cause of maternal death. Identification of safe and cost-effective hemostatic treatment options remains crucial as a supplement to surgery and uterotonic agents.

OBJECTIVE

This review summarizes the background, current evidence and recommendations with regard to the role of fibrinogen, tranexamic acid, prothrombin complex concentrate, desmopressin, and recombinant factor VIIa in the treatment of patients with postpartum hemorrhage. The benefits and evidence behind traditional standard laboratory tests and viscoelastic hemostatic assays, i.e. thromboelastography TEG(®) and thromboelastometry ROTEM(®) , are discussed. In addition we assess and elaborate on the current paradigm and evidence for transfusion of these patients.

DATA SOURCES

Publications between 1994 and 2014 were identified from PubMed, EMBASE, Cochrane Library databases, and ClinicalTrial.gov.

RESULTS

Viscoelastic hemostatic assays were found to provide a real-time continuum of coagulation and fibrinolysis when introduced as a supplement in transfusion management of postpartum hemorrhage. Fibrinogen should be considered when hypofibrinogenemia is identified. Early administration of 1-2 g tranexamic acid is recommended, followed by an additional dose in cases of ongoing bleeding. Uncontrolled hemorrhage requires early balanced transfusion.

CONCLUSION

Despite the lack of conclusive evidence for optimal hemostatic resuscitation in postpartum hemorrhage, the use of viscoelastic hemostatic assays, fibrinogen, tranexamic acid and balanced transfusion therapy may prove to be potentially pivotal in the treatment of postpartum hemorrhage.