Tranexamic Acid for the Prevention of Blood Loss after Cesarean Delivery

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 the prevention and the treatment of primary postpartum haemorrhage: a systematic review

Tranexamic acid (TA) has been proposed for preventing or treating primary postpartum haemorrhage (PPH), which is the leading cause of maternal morbidity and mortality worldwide. We conducted a systematic literature search to the TA role in managing PPH in vaginal and caesarean delivery. Twenty-seven randomised controlled trials (RCTs) (33,302 women) were identified. Three RCTs investigated TA for preventing PPH after vaginal delivery and 22 after caesarean section. None demonstrated a preventive effect on secondary clinical outcomes related to blood loss. Two trials evaluated TA for treating PPH after vaginal and caesarean delivery. Only the WOMAN trial showed that 1 g of TA is effective. In conclusion, TA is considered useful and is recommended or advised for treating PPH. Conversely, available evidence on the prophylactic role is still limited, and this use is not supported. Further investigation is recommended. In this regard, stronger and more reliable outcomes than blood loss should be considered.

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.

Validation of the Developed Zero-Order Infrared Spectrophotometry Method for Qualitative and Quantitative Analyses of Tranexamic Acid in Marketed Tablets

(1) Background: The functional groups present in tranexamic acid allow direct infrared detection analysis. This study aimed to develop, apply, and validate an infrared spectrophotometry method used for qualitative and quantitative analyses of tranexamic acid in marketed tablets. (2) Methods: This was a descriptive observational study that consisted of several stages: determining the specific wavenumber for analysis, obtaining a simple linear regression equation, analyzing tranexamic acid both qualitatively and quantitatively, and validating the developed method for routine analysis. (3) Results: The peak analysis obtained a range of baseline wavenumbers from 1679.17 to 1295.25 cm⁻¹. The regression equation obtained was Y = 310.8527 × X + 0.9718, and the coefficient of determination (R²) obtained was 0.9994. The tranexamic acids in marketed tablets overall have a similarity index value of more than 0.90 and overall have levels ranging between 97.0% and 103.0%. The infrared spectrophotometry method that was successfully developed, applied, and validated for qualitative and quantitative analyses of tranexamic acid in marketed tablets meets the requirements both qualitatively and quantitatively of the tablet monograph. (4) Conclusions: The infrared spectrophotometry method has been validated and meets the requirements for accuracy, precision, detection limit, quantitation limit, linearity, range, and specificity.

Obstetrical Hemorrhage

Obstetric hemorrhage is a leading cause of morbidity and mortality. Prevention includes identifying patients with risk factors and actively managing the third stage of labor. The anesthesiologist should be ready to manage hemorrhage with general strategies as well as strategies tailored to the specific cause of hemorrhage. Both neuraxial anesthesia and general anesthesia are appropriate in different situations. Treatments proven to be effective include increasing the oxytocin infusion, administering tranexamic acid early, guiding transfusion with point-of-care tests, and using cell salvage. Utilization of protocols and checklists within systems that encourage effective communication between teams should be implemented.

Tranexamic Acid Use in the Postpartum Period Since the WOMAN Trial: A retrospective chart review

OBJECTIVE

To analyze the use of tranexamic acid (TXA) in postpartum patients since the WOMAN trial.

METHODS

A retrospective recrods review was conducted from May 2017 to March 2020 at a tertiary care centre to identify all patients who received TXA for postpartum bleeding. The primary outcome was to identify the proportion of patients who received TXA as per World Health Organization guidelines using the results of the WOMAN trial.

RESULTS

A total of 231 patients were included in our analysis. Use increased over time with 18 patients in 2017, 51 in 2018, and 134 in 2019 receiving TXA. In all, 203 patients (87.9%) received TXA within recommended guidelines, and these patients were less likely to require surgery or interventional radiology (12.3% vs. 42.9%, P < 0.001) or blood transfusion (23.6% vs. 42.9%, P = 0.030), and they had a lower likelihood of overall adverse events (LR 1.62 (1.6) vs. 2.60 (2.0), P = 0.024). TXA was commonly used as the first-line agent for postpartum bleeding (48.9% of patients), and was administered at cesarean section (77.0%) and when estimated blood loss did not meet criteria for "true" postpartum hemorrhage (41.6% of patients). Use of TXA as the first medication was associated with fewer adverse outcomes overall than misoprostol (P = 0.035). A shorter time to administration of the first medication was associated with shorter postpartum admission time (P = 0.042).

CONCLUSIONS

The majority of patients received TXA within guidelines and experience fewer adverse outcomes. Further study is needed to identify the best order of TXA administration with additional uterotonics and whether TXA should be used prophylactically in some groups for postpartum bleeding.

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.

Tranexamsäure reduziert Blutverlust nach Sectio

Peri- und postpartale Blutungen bestimmen ganz wesentlich die mütterliche Morbidität und Mortalität. Der Nutzen des Antifibrinolytikums Tranexamsäure wird kontrovers diskutiert. In der TRAAP2-Studie hatte die prophylaktische Gabe nach Sectio caesarea als Ergänzung zu Uterotonika zwar statistisch signifikante Effekte, die sich im Unterschied zur Placebogruppe aber klinisch nur wenig auswirkten.

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.

WOMAN-PharmacoTXA trial: Study protocol for a randomised controlled trial to assess the pharmacokinetics and pharmacodynamics of intramuscular, intravenous and oral administration of tranexamic acid in women giving birth by caesarean section

Background: Intravenous tranexamic acid (TXA) within 3 hours of birth significantly reduces death due to bleeding in women with postpartum haemorrhage (PPH). Most PPH deaths occur in the first hours after giving birth and treatment delay decreases survival.  One barrier to rapid TXA treatment is the need for intravenous injection. Intramuscular injection and oral solution of TXA would be easier and faster to administer and would require less training. However, the pharmacokinetics (PK), pharmacodynamics and safety of TXA administered by different routes in pregnant women have not been established. The main aim of this study is to ascertain whether IM and oral solution of TXA will be absorbed at levels sufficient to inhibit fibrinolysis in pregnant women.

Methods: WOMAN-PharmacoTXA is a prospective, randomised, open label trial to be conducted in Zambia and Pakistan.  Adult women undergoing caesarean section with at least one risk factor for PPH will be included.  Women will be randomised to receive one of the following about 1 hour prior to caesarean section: 1-gram TXA IV, 1-gram TXA IM, 4-grams TXA oral solution or no TXA. Randomisation will continue until 120 participants with at least six post randomisation PK samples are included. TXA concentration in maternal blood samples will be measured at baseline and at different time points during 24 hours after receipt of intervention. Blood TXA concentration will be measured from the umbilical cord and neonate.

The primary endpoint is maternal blood TXA concentrations over time. Secondary outcomes include umbilical cord and neonate TXA concentration D-dimer concentration, blood loss and clinical diagnosis of PPH, injection site reactions and maternal and neonate adverse events.

Discussion: The WOMAN-PharmacoTXA trial will provide important data on pharmacokinetics, pharmacodynamics and safety of TXA after IV, intramuscular and oral administration in women giving birth by caesarean section.

Trial registration: ClincalTrials.gov, NCT04274335 (18/02/2020).