Tranexamic acid for the prevention of blood loss after cesarean section: an updated systematic review and meta-analysis of randomized controlled trials

Is tranexamic acid appropriate for all patients undergoing high-risk surgery?

PURPOSE OF REVIEW

Tranexamic acid (TXA), an antifibrinolytic agent, reduces surgical bleeding in a variety of procedures, such as cardiac, orthopedic, abdominal, and urologic surgery, cesarean section, and neurosurgery. However, there are surgical interventions for which its use is not yet widespread, and some caution persists because of concerns regarding thrombotic risk. The purpose of this review is to analyze the most recent evidence in various subgroups of surgical specialties and the association of TXA with thrombotic events and other side effects (e.g. seizures).

RECENT FINDINGS

Recent clinical trials and meta-analyses have shown that the efficacy and safety vary according to the clinical context, timing of administration, and dose. Some reports found that TXA reduces major bleeding by 25% without a significant increase in thrombotic events.

SUMMARY

Wider use of TXA has the potential to improve surgical safety, avoid unnecessary blood use, and save healthcare funds.

Prophylactic tranexamic acid for reducing blood loss in pregnant females undergoing cesarean section: A systematic review and meta-analysis

OBJECTIVE

We aim to assess the efficacy of prophylactic tranexamic acid (TXA) in reducing blood loss after cesarean section (CS).

METHODS

We systematically searched PubMed and Embase for randomized controlled trials published between 1990 and 2023 to conduct a meta-analysis on adult women undergoing CS and receiving prophylactic TXA.

RESULTS

Twenty-four trials, comprising 19 584 participants, were included. Most studies included women with healthy, full-term, singleton pregnancies. The pooled estimate showed a reduction in mean blood loss in the TXA arm with a standardized mean difference (SMD) of -1.50 (-2.03, -0.98: p < 0.001). There was a high level of heterogeneity (I2 98.86%). A subgroup analysis demonstrated no statistical difference in the effect of TXA on blood loss at 2 h of follow-up with SMD of -2.24 (-3.23, -1.35) compared to -1.07 (-1.56, -0.58) and -1.10 (-2.62, -0.42) at 24 and 48 h, respectively (p = 0.11). The effect of TXA on blood loss was smaller in high-income countries with SMD -0.24 (-0.44, -0.04) (I2 63%) than in low-/middle-income countries -1.78 (-2.35, -1.21) with I2 98%. Only three studies had low risk of bias and the effect of TXA from two of them was SMD -0.31 (-0.54, -0.09) (I2 0%).

CONCLUSIONS

Despite the apparent beneficial effect of TXA in reducing blood loss after CS for women with uncomplicated term pregnancies, heterogeneity remains a serious concern. The current body of knowledge consists predominantly of small, likely biased studies, and large unbiased studies show only limited effects of prophylactic TXA.

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.

Evidence-based cesarean delivery: preoperative management (part 7)

Preoperative preparation for cesarean delivery is a multistep approach for which protocols should exist at each hospital system. These protocols should be guided by the findings of this review. The interventions reviewed and recommendations made for this review have a common goal of decreasing maternal and neonatal morbidity and mortality related to cesarean delivery. The preoperative period starts before the patient's arrival to the hospital and ends immediately before skin incision. The Centers for Disease Control and Prevention recommends showering with either soap or an antiseptic solution at least the night before a procedure. Skin cleansing in addition to this has not been shown to further decrease rates of infection. Hair removal at the cesarean skin incision site is not necessary, but if preferred by the surgical team then clipping or depilatory creams should be used rather than shaving. Preoperative enema is not recommended. A clear liquid diet may be ingested up to 2 hours before and a light meal up to 6 hours before cesarean delivery. Consider giving a preoperative carbohydrate drink to nondiabetic patients up to 2 hours before planned cesarean delivery. Weight-based intravenous cefazolin is recommended 60 minutes before skin incision: 1-2 g intravenous for patients without obesity and 2 g for patients with obesity or weight ≥80 kg. Adjunctive azithromycin 500 mg intravenous is recommended for patients with labor or rupture of membranes. Preoperative gabapentin can be considered as a way to decrease pain scores with movement in the postoperative period. Tranexamic acid (1 g in 10-20 mL of saline or 10 mg/kg intravenous) is recommended prophylactically for patients at high risk of postpartum hemorrhage and can be considered in all patients. Routine use of mechanical venous thromboembolism prophylaxis is recommended preoperatively and is to be continued until the patient is ambulatory. Music and active warming of the patient, and adequate operating room temperature improves outcomes for the patient and neonate, respectively. Noise levels should allow clear communication between teams; however, a specific decibel level has not been defined in the data. Patient positioning with left lateral tilt decreases hypotensive episodes compared with right lateral tilt, which is not recommended. Manual displacers result in fewer hypotensive episodes than left lateral tilt. Both vaginal and skin preparation should be performed with either chlorhexidine (preferred) or povidone iodine. Placement of an indwelling urinary catheter is not necessary. Nonadhesive drapes are recommended. Cell salvage, although effective for high-risk patients, is not recommended for routine use. Maternal supplemental oxygen does not improve outcomes. A surgical safety checklist (including a timeout) is recommended for all cesarean deliveries.

Evaluating tranexamic acid for the prevention and treatment of obstetric hemorrhage

PURPOSE OF REVIEW

Tranexamic acid (TXA) has emerged as a promising pharmacological adjunct to treat and prevent postpartum hemorrhage (PPH). We provide an overview of TXA, including its pharmacology, key findings of randomized trials and observational studies, and critical patient safety information.

RECENT FINDINGS

Pharmacokinetic data indicate that TXA infusions result in peak plasma concentration within 3 min (range: 1-6.6 min). Ex-vivo pharmacodynamic data suggest that low-dose TXA (5 mg/kg) inhibits maximum lysis for at least 1 h. In predominantly developing countries, TXA has demonstrated a 19% reduction in the risk of bleeding-related death among patients with PPH. Based on high-quality randomized trials, TXA prophylaxis does not effectively reduce the risk of PPH during vaginal delivery and is likely ineffective in reducing the PPH risk during cesarean delivery. TXA exposure does not increase the risk of maternal thrombotic events. Maternal deaths have occurred from accidental intrathecal TXA injection from look-alike medication errors.

SUMMARY

TXA has shown promise as an important adjunct for PPH treatment, especially in low-resource settings. However, TXA is not recommended as PPH prophylaxis during vaginal or cesarean delivery. Patient safety initiatives should be prioritized to prevent maternal death from accidental intrathecal TXA injection.

Prophylactic tranexamic acid for reducing intraoperative blood loss during cesarean section in women at high risk of postpartum hemorrhage: A double-blind placebo randomized controlled trial

BACKGROUND

Postpartum hemorrhage remains a leading cause of maternal mortality especially in developing countries. The majority of previous trials on the effectiveness of tranexamic acid in reducing blood loss were performed in low-risk women for postpartum hemorrhage. A recent Cochrane Systematic Review recommended that further research was needed to determine the effects of prophylactic tranexamic acid for preventing intraoperative blood loss in women at high risk of postpartum hemorrhage.

OBJECTIVE

This study aimed to evaluate the effectiveness and safety of tranexamic acid in reducing intraoperative blood loss when given prior to cesarean delivery in women at high risk of postpartum hemorrhage.

STUDY DESIGN

The study is a double-blind randomized controlled trial.

METHODS

The study consisted of 200 term pregnant women and high-risk preterm pregnancies scheduled for lower-segment cesarean delivery at Enugu State University of Science and Technology, Teaching Hospital, Parklane, Enugu, Nigeria. The participants were randomized into two arms (intravenous 1 g of tranexamic acid or placebo) in a ratio of 1:1. The participants received either 1 g of tranexamic acid or placebo (20 mL of normal saline) intravenously at least 10 min prior to commencement of the surgery. The primary outcome measures were the mean intraoperative blood loss and hematocrit change 48 h postoperatively.

RESULTS

The baseline sociodemographic characteristics were similar in both groups. The tranexamic acid group when compared to the placebo group showed significantly lower mean blood loss (442.94 ± 200.97 versus 801.28 ± 258.68 mL; p = 0.001), higher mean postoperative hemoglobin (10.39 + 0.96 versus 9.67 ± 0.86 g/dL; p = 0.001), lower incidence of postpartum hemorrhage (1.0% versus 19.0%; p = 0.001), and lower need for use of additional uterotonic agents after routine management of the third stage of labor (39.0% versus 68.0%; p = 0.001), respectively. However, there was no significant difference in the mean preoperative hemoglobin (11.24 ± 0.88 versus 11.15 ± 0.90 g/dL; p = 0.457), need for other surgical intervention for postpartum hemorrhage (p > 0.05), and reported side effect, respectively, between the two groups.

CONCLUSION

Prophylactic administration of tranexamic acid significantly decreases postpartum blood loss, improves postpartum hemoglobin, decreases the need for additional uterotonics, and prevents postpartum hemorrhage following cesarean section in pregnant women at high risk of postpartum hemorrhage. Its routine use during cesarean section in high-risk women may be encouraged.The trial was registered in the Pan-African Clinical Trial Registry with approval number PACTR202107872851363.

Prehospital tranexamic acid in trauma patients: a systematic review and meta-analysis of randomized controlled trials

Background

Prehospital tranexamic acid (TXA) may hold substantial benefits for trauma patients; however, the data underlying its efficacy and safety is scarce.

Methods

We searched PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov from inception to July 2023 for all randomized controlled trials (RCTs) investigating prehospital TXA in trauma patients as compared to placebo or standard care without TXA. Data were pooled under a random-effects model using RevMan 5.4 with risk ratio (RR) and mean difference (MD) as the effect measures.

Results

A total of three RCTs were included in this review. Regarding the primary outcomes, prehospital TXA reduced the risk of 1-month mortality (RR 0.82, 95% CI 0.69-0.97) but did not increase survival with a favorable functional outcome at 6 months (RR 1.00, 95% CI 0.93-1.09). Prehospital TXA also reduced the risk of 24-h mortality but did not affect the risk of mortality due to bleeding and traumatic brain injury. There was no significant difference between the TXA and control groups in the incidence of RBC transfusion, and the number of ventilator- and ICU-free days. Prehospital TXA did not increase the risk of adverse events except for a small increase in the incidence of infections.

Conclusion

Prehospital TXA is useful in reducing mortality in trauma patients without a notable increase in the risk of adverse events. However, there was no effect on the 6-month favorable functional status. Further large-scale trials are required to validate the aforementioned findings.

Systematic review registration

PROSPERO (CRD42023451759).

Tranexamic acid for the prevention of postpartum bleeding: Protocol for a systematic review and individual patient data meta-analysis

Tranexamic acid (TXA) reduces the risk of death and is recommended as a treatment for women with severe postpartum bleeding. There is hope that giving TXA shortly before or immediately after birth could prevent postpartum bleeding. Extending the use of TXA to prevent harmful postpartum bleeding could improve outcomes for millions of women; however we must carefully consider the balance of benefits and potential harms. This article describes the protocol for a systematic review and individual patient data (IPD) meta-analysis to assess the effectiveness and safety of TXA for preventing postpartum bleeding in all women giving birth, and to explore how the effects vary by underlying risk and other patient characteristics.   Methods: We will search for prospectively registered, randomised controlled trials involving 500 patients or more assessing the effects of TXA in women giving birth. Two authors will extract data and assess risk of bias. IPD data will be sought from eligible trials. Primary outcomes will be life-threatening bleeding and thromboembolic events. We will use a one-stage model to analyse the data. Subgroup analyses will be conducted to explore whether the effectiveness and safety of TXA varies by underlying risk, type birth, maternal haemoglobin (Hb), and timing of TXA. This protocol is registered on PROSPERO (CRD42022345775).  Conclusions: This systematic review and IPD meta-analysis will address important clinical questions about the effectiveness and safety of the use of TXA for the prevention of postpartum bleeding that cannot be answered reliably using aggregate data and will inform the decision of who to treat.   PROSPERO registration: CRD42022345775  Keywords   Anti-fibrinolytics; Tranexamic acid; childbirth; postpartum haemorrhage; meta-analysis.