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

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.

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

OBJECTIVES

Perioperative bleeding poses a significant issue during thoracic surgery. Tranexamic acid (TXA) is one of the most commonly used antifibrinolytic agents for surgical patients. The purpose of the current study was designed to investigate the efficacy and safety of TXA in patients undergoing thoracic surgery.

METHODS

An extensive search of PubMed, Web of Science (WOS), Cochrane Library (trials), Embase, OVID, China National Knowledge Infrastructure (CNKI), Wanfang, and VIP electronic databases was performed to identify studies published between the inception of these databases and March 2023. The primary outcomes included perioperative blood loss and blood transfusions. Secondary outcomes of interest included the length of stay (LOS) in hospital and the incidence of thromboembolic events. Weighted mean differences (WMDs) or odds ratios (OR) with 95% confidence intervals (CI) were used to determine treatment effects for continuous and dichotomous variables, respectively.

RESULTS

Five qualified studies including 307 thoracic surgical patients were included in the current study. Among them, 65 patients were randomly allocated to the group receiving TXA administration (the TXA group); the other 142 patients were assigned to the group not receiving TXA administration (the control group). TXA significantly reduced the quantity of hemorrhage in the postoperative period (postoperative 12h: WMD = -81.90 ml; 95% CI: -139.55 to -24.26; P = 0.005; postoperative 24h: WMD = -97.44 ml; 95% CI: -121.44 to -73.44; P< 0.00001); The intraoperative blood transfusion volume (WMD = -0.54 units; 95% CI: -1.06 to -0.03; P = 0.04); LOS in hospital (WMD = -0.6 days; 95% CI: -1.04 to -0.16; P = 0.008); And there was no postoperative thromboembolic event reported in the included studies.

CONCLUSIONS

The present study demonstrated that TXA significantly decreased blood loss within 12 and 24 hours postoperatively. A qualitative review did not identify elevated risks of safety outcomes such as thromboembolic events. It also suggested that TXA administration was associated with shorter LOS in hospital as compared to control. To validate this further, additional well-planned and adequately powered randomized studies are necessary.

Prophylactic tranexamic acid in Cesarean delivery: an updated meta-analysis with a trial sequential analysis

PURPOSE

Postpartum hemorrhage (PPH) is a leading cause of maternal mortality worldwide. Although several studies on the prophylactic use of tranexamic acid (TXA) in parturients undergoing Cesarean delivery have been published, conflicting results raise questions regarding its use. Thus, we aimed to investigate the safety and efficacy of PPH prophylaxis with TXA.

SOURCE

We searched PubMed®, Embase, Cochrane Central, and ClinicalTrials.gov for randomized controlled trials (RCTs) comparing prophylactic TXA with placebo or no treatment in parturients undergoing Cesarean delivery. Our main outcomes were PPH, any blood transfusion, need for additional uterotonics, and adverse events. We performed a trial sequential analysis (TSA) of all outcomes to investigate the reliability and conclusiveness of findings.

PRINCIPAL FINDINGS

We included 38 RCTs including 22,940 parturients, 11,535 (50%) of whom were randomized to receive prophylactic TXA. Patients treated with TXA had significantly fewer cases of PPH (risk ratio [RR], 0.51; 95% confidence interval [CI], 0.38 to 0.69; P < 0.001); less blood transfusion (RR, 0.43; 95% CI, 0.30 to 0.61; P < 0.001), and less use of additional uterotonics (RR, 0.52; 95% CI, 0.40 to 0.68; P < 0.001). No significant differences were found between the groups in terms of adverse effects and thromboembolic events.

CONCLUSION

Prophylactic TXA administration for parturients undergoing Cesarean delivery significantly reduced blood loss, without increasing adverse events, supporting its use as a safe and effective strategy for reducing PPH in this population.

STUDY REGISTRATION

PROSPERO (CRD42023422188); first submitted 27 April 2023.

Clinical nursing value of predictive nursing in reducing complications of pregnant women undergoing short-term massive blood transfusion during cesarean section

BACKGROUND

Cesarean hemorrhage is one of the serious complications, and short-term massive blood transfusion can easily cause postoperative infection and physical stress response. However, predictive nursing intervention has important clinical significance for it.

AIM

To explore the effect of predictive nursing intervention on the stress response and complications of women undergoing short-term mass blood transfusion during cesarean section (CS).

METHODS

A clinical medical record of 100 pregnant women undergoing rapid mass blood transfusion during sections from June 2019 to June 2021. According to the different nursing methods, patients divided into control group (n = 50) and observation group (n = 50). Among them, the control group implemented routine nursing, and the observation group implemented predictive nursing intervention based on the control group. Moreover, compared the differences in stress response, complications, and pain scores before and after the nursing of pregnant women undergoing rapid mass blood transfusion during CS.

RESULTS

The anxiety and depression scores of pregnant women in the two groups were significantly improved after nursing, and the psychological stress response of the observation group was significantly lower than that of the control group (P < 0.05). The heart rate and mean arterial pressure (MAP) of the observation group during delivery were lower than those of the control group, and the MAP at the end of delivery was lower than that of the control group (P < 0.05). Moreover, different pain scores improved significantly in both groups, with the observation group considerably less than the control group (P < 0.05). After nursing, complications such as skin rash, urinary retention, chills, diarrhea, and anaphylactic shock in the observation group were 18%, which significantly higher than in the control group (4%) (P < 0.05).

CONCLUSION

Predictive nursing intervention can effectively relieve the pain, reduce the incidence of complications, improve mood and stress response, and serve as a reference value for the nursing of women undergoing rapid mass transfusion during CS.

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.

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

OBJECTIVE

Tranexamic acid is a cost-effective intervention for the prevention of postpartum hemorrhage among women who undergo cesarean delivery, but the evidence to support its use is conflicting. We conducted this meta-analysis to evaluate the efficacy and safety of tranexamic acid in low- and high-risk cesarean deliveries.

DATA SOURCES

We searched MEDLINE (via PubMed), Embase, the Cochrane Library, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform portal from inception to April 2022 (updated October 2022 and February 2023) with no language restrictions. In addition, grey literature sources were also explored.

STUDY ELIGIBILITY CRITERIA

All randomized controlled trials that investigated the prophylactic use of intravenous tranexamic acid in addition to standard uterotonic agents among women who underwent cesarean deliveries in comparison with a placebo, standard treatment, or prostaglandins were included in this meta-analysis.

METHODS

We used the revised Cochrane Risk of Bias tool (RoB 2.0) to assess the quality of the included randomized controlled trials. RevMan 5.4 was used to conduct all statistical analyses using a random-effects model.

RESULTS

We included 50 randomized controlled trials (6 in only high-risk patients and 2 with prostaglandins as the comparator) that evaluated tranexamic acid in our meta-analysis. Tranexamic acid reduced the risk for blood loss >1000 mL, the mean total blood loss, and the need for blood transfusion in both low- and high-risk patients. Tranexamic acid was associated with a beneficial effect in the secondary outcomes, including a decline in hemoglobin levels and the need for additional uterotonic agents. Tranexamic acid increased the risk for nonthromboembolic adverse events but, based on limited data, did not increase the incidence of thromboembolic events. The administration of tranexamic acid before skin incision, but not after cord clamping, was associated with a large benefit. The quality of evidence was rated as low to very low for outcomes in the low-risk population and moderate for most outcomes in the high-risk subgroup.

CONCLUSION

Tranexamic acid may reduce the risk for blood loss in cesarean deliveries with a higher benefit observed in high-risk patients, but the lack of high-quality evidence precludes any strong conclusions. The administration of tranexamic acid before skin incision, but not after cord clamping, was associated with a large benefit. Additional studies, especially in the high-risk population and focused on evaluating the timing of tranexamic acid administration, are needed to confirm or refute these findings.

Guidelines on perioperative optimization protocol for the adult patient 2023

OBJECTIVE

The French Society of Anesthesiology and Intensive Care Medicine [Société Française d'Anesthésie et de Réanimation (SFAR)] aimed at providing guidelines for the implementation of perioperative optimization programs.

DESIGN

A consensus committee of 29 experts from the SFAR was convened. A formal conflict-of-interest policy was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industry funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence.

METHODS

Four fields were defined: 1) Generalities on perioperative optimization programs; 2) Preoperative measures; 3) Intraoperative measures and; 4) Postoperative measures. For each field, the objective of the recommendations was to answer a number of questions formulated according to the PICO model (population, intervention, comparison, and outcomes). Based on these questions, an extensive bibliographic search was carried out using predefined keywords according to PRISMA guidelines and analyzed using the GRADE® methodology. The recommendations were formulated according to the GRADE® methodology and then voted on by all the experts according to the GRADE grid method. As the GRADE® methodology could have been fully applied for the vast majority of questions, the recommendations were formulated using a "formalized expert recommendations" format.

RESULTS

The experts' work on synthesis and application of the GRADE® method resulted in 30 recommendations. Among the formalized recommendations, 19 were found to have a high level of evidence (GRADE 1±) and ten a low level of evidence (GRADE 2±). For one recommendation, the GRADE methodology could not be fully applied, resulting in an expert opinion. Two questions did not find any response in the literature. After two rounds of rating and several amendments, strong agreement was reached for all the recommendations.

CONCLUSIONS

Strong agreement among the experts was obtained to provide 30 recommendations for the elaboration and/or implementation of perioperative optimization programs in the highest number of surgical fields.

Tranexamic Acid to Prevent Obstetrical Hemorrhage after Cesarean Delivery

BACKGROUND

Prophylactic use of tranexamic acid at the time of cesarean delivery has been shown to decrease the calculated blood loss, but the effect on the need for blood transfusions is unclear.

METHODS

We randomly assigned patients undergoing cesarean delivery at 31 U.S. hospitals to receive either tranexamic acid or placebo after umbilical-cord clamping. The primary outcome was a composite of maternal death or blood transfusion by hospital discharge or 7 days post partum, whichever came first. Key secondary outcomes were estimated intraoperative blood loss of more than 1 liter (prespecified as a major secondary outcome), interventions for bleeding and related complications, the preoperative-to-postoperative change in the hemoglobin level, and postpartum infectious complications. Adverse events were assessed.

RESULTS

A total of 11,000 participants underwent randomization (5529 to the tranexamic acid group and 5471 to the placebo group); scheduled cesarean delivery accounted for 50.1% and 49.2% of the deliveries in the respective groups. A primary-outcome event occurred in 201 of 5525 participants (3.6%) in the tranexamic acid group and in 233 of 5470 (4.3%) in the placebo group (adjusted relative risk, 0.89; 95.26% confidence interval [CI], 0.74 to 1.07; P = 0.19). Estimated intraoperative blood loss of more than 1 liter occurred in 7.3% of the participants in the tranexamic acid group and in 8.0% of those in the placebo group (relative risk, 0.91; 95% CI, 0.79 to 1.05). Interventions for bleeding complications occurred in 16.1% of the participants in the tranexamic acid group and in 18.0% of those in the placebo group (relative risk, 0.90; 95% CI, 0.82 to 0.97); the change in the hemoglobin level was -1.8 g per deciliter and -1.9 g per deciliter, respectively (mean difference, -0.1 g per deciliter; 95% CI, -0.2 to -0.1); and postpartum infectious complications occurred in 3.2% and 2.5% of the participants, respectively (relative risk, 1.28; 95% CI, 1.02 to 1.61). The frequencies of thromboembolic events and other adverse events were similar in the two groups.

CONCLUSIONS

Prophylactic use of tranexamic acid during cesarean delivery did not lead to a significantly lower risk of a composite outcome of maternal death or blood transfusion than placebo. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development; ClinicalTrials.gov number, NCT03364491.).

Does Tranexamic Acid Reduce the Blood Loss in Various Surgeries? An Umbrella Review of State-of-the-Art Meta-Analysis

Background: Tranexamic acid (TXA) has been applied in various types of surgery for hemostasis purposes. The efficacy and safety of TXA are still controversial in different surgeries. Guidelines for clinical application of TXA are needed. Materials and method: We systematically searched multiple medical databases for meta-analyses examining the efficacy and safety of TXA. Types of surgery included joint replacement surgery, other orthopedic surgeries, cardiac surgery, cerebral surgery, etc. Outcomes were blood loss, blood transfusion, adverse events, re-operation rate, operative time and length of hospital stay, hemoglobin (Hb) level, and coagulation function. Assessing the methodological quality of systematic reviews 2 (AMSTAR 2) and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) were used for quality assessment of the included meta-analyses. Overlapping reviews were evaluated by calculating the corrected covered area (CCA). Result: In all, we identified 47 meta-analyses, of which 44 of them were of "high" quality. A total of 319 outcomes were evaluated, in which 58 outcomes were assessed as "high" quality. TXA demonstrates significant hemostatic effects in various surgeries, with lower rates of blood transfusion and re-operation, shorter operative time and length of stay, and higher Hb levels. Besides, TXA does not increase the risk of death and vascular adverse events, but it is a risk factor for seizure (a neurological event) in cardiac surgery. Conclusion: Our study demonstrates that TXA has a general hemostatic effect with very few adverse events, which indicates TXA is the recommended medication to prevent excessive bleeding and reduce the blood transfusion rate. We also recommend different dosages of TXA for different types of adult surgery. However, we could not recommend a unified dosage for different surgeries due to the heterogeneity of the experimental design. Systematic Review Registration: clinicaltrials.gov/, identifier CRD42021240303.

Prediction and Evaluation of Machine Learning Algorithm for Prediction of Blood Transfusion during Cesarean Section and Analysis of Risk Factors of Hypothermia during Anesthesia Recovery

Objective

To explore the application of machine learning algorithm in the prediction and evaluation of cesarean section, predicting the amount of blood transfusion during cesarean section and to analyze the risk factors of hypothermia during anesthesia recovery.

Methods

(1)Through the hospital electronic medical record of medical system, a total of 600 parturients who underwent cesarean section in our hospital from June 2019 to December 2020 were included. The maternal age, admission time, diagnosis, and other case data were recorded. The routine method of cesarean section was intraspinal anesthesia, and general anesthesia was only used for patients' strong demand, taboo, or failure of intraspinal anesthesia. According to the standard of intraoperative bleeding, the patients were divided into two groups: the obvious bleeding group (MH group, N = 154) and nonobvious hemorrhage group (NMH group, N = 446). The preoperative, intraoperative, and postoperative indexes of parturients in the two groups were analyzed and compared. Then, the risk factors of intraoperative bleeding were screened by logistic regression analysis with the occurrence of obvious bleeding as the dependent variable and the factors in the univariate analysis as independent variables. In order to further predict intraoperative blood transfusion, the standard cases of recesarean section and variables with possible clinical significance were included in the prediction model. Logistic regression, XGB, and ANN3 machine learning algorithms were used to construct the prediction model of intraoperative blood transfusion. The area under ROC curve (AUROC), accuracy, recall rate, and F1 value were calculated and compared. (2) According to whether hypothermia occurred in the anesthesia recovery room, the patients were divided into two groups: the hypothermia group (N = 244) and nonhypothermia group (N = 356). The incidence of hypothermia was calculated, and the relevant clinical data were collected. On the basis of consulting the literatures, the factors probably related to hypothermia were collected and analyzed by univariate statistical analysis, and the statistically significant factors were analyzed by multifactor logistic regression analysis to screen the independent risk factors of hypothermia in anesthetic convalescent patients.

Results

(1) First of all, we compared the basic data of the blood transfusion group and the nontransfusion group. The gestational age of the transfusion group was lower than that of the nontransfusion group, and the times of cesarean section and pregnancy in the transfusion group were higher than those of the non-transfusion group. Secondly, we compared the incidence of complications between the blood transfusion group and the nontransfusion group. The incidence of pregnancy complications was not significantly different between the two groups (P > 0.05). The incidence of premature rupture of membranes in the nontransfusion group was higher than that in the transfusion group (P < 0.05). There was no significant difference in the fetal umbilical cord around neck, amniotic fluid index, and fetal heart rate before operation in the blood transfusion group, but the thickness of uterine anterior wall and the levels of Hb, PT, FIB, and TT in the blood transfusion group were lower than those in the nontransfusion group, while the number of placenta previa and the levels of PLT and APTT in the blood transfusion group were higher than those in the nontransfusion group. The XGB prediction model finally got the 8 most important features, in the order of importance from high to low: preoperative Hb, operation time, anterior wall thickness of the lower segment of uterus, uterine weakness, preoperative fetal heart, placenta previa, ASA grade, and uterine contractile drugs. The higher the score, the greater the impact on the model. There was a linear correlation between the 8 features (including the correlation with the target blood transfusion). The indexes with strong correlation with blood transfusion included the placenta previa, ASA grade, operation time, uterine atony, and preoperative Hb. Placenta previa, ASA grade, operation time, and uterine atony were positively correlated with blood transfusion, while preoperative Hb was negatively correlated with blood transfusion. In order to further compare the prediction ability of the three machine learning methods, all the samples are randomly divided into two parts: the first 75% training set and the last 25% test set. Then, the three models are trained again on the training set, and at this time, the model does not come into contact with the samples in any test set. After the model training, the trained model was used to predict the test set, and the real blood transfusion status was compared with the predicted value, and the F1, accuracy, recall rate, and AUROC4 indicators were checked. In terms of training samples and test samples, the AUROC of XGB was higher than that of logistic regression, and the F1, accuracy, and recall rate of XGB of ANN were also slightly higher than those of logistic regression and ANN. Therefore, the performance of XGB algorithm is slightly better than that of logistic regression and ANN. (2) According to the univariate analysis of hypothermia during the recovery period of anesthesia, there were significant differences in ASA grade, mode of anesthesia, infusion volume, blood transfusion, and operation duration between the normal body temperature group and hypothermia group (P < 0.05). Logistic regression analysis showed that ASA grade, anesthesia mode, infusion volume, blood transfusion, and operation duration were all risk factors of hypothermia during anesthesia recovery.

Conclusion

In this study, three machine learning algorithms were used to analyze the large sample of clinical data and predict the results. It was found that five important predictive variables of blood transfusion during recesarean section were preoperative Hb, expected operation time, uterine weakness, placenta previa, and ASA grade. By comparing the three algorithms, the prediction effect of XGB may be more accurate than that of logistic regression and ANN. The model can provide accurate individual prediction for patients and has good prediction performance and has a good prospect of clinical application. Secondly, through the analysis of the risk factors of hypothermia during the recovery period of cesarean section, it is found that ASA grade, mode of anesthesia, amount of infusion, blood transfusion, and operation time are all risk factors of hypothermia during the recovery period of cesarean section. In line with this, the observation of this kind of patients should be strengthened during cesarean section.

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 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.

Tranexamic acid to reduce operative blood loss in brain tumor surgery: A meta-analysis

Background:

Major blood loss during neurosurgery may result in a variety of complications, such as potentially fatal hemodynamic instability. Brain tumor and skull base surgery is among the high bleeding risk procedures. Tranexamic acid (TXA) has been found to reduce bleeding events in various fields of medicine.

Methods:

We searched for all randomized controlled trials published in English or Bahasa which compared the use of TXA with placebo in brain tumor surgery. The studies should include adult patients with intracranial tumor who received TXA before skin incision. The primary and secondary outcomes are intraoperative blood loss and the need of transfusion.

Results:

This meta-analysis included a total of 200 patients from three studies. TXA resulted in less blood loss with pooled mean difference of −292.80 (95% CI, −431.63, −153.96, P<0.05). The need of transfusion was not significant between TXA and control group (pooled mean difference −85.36, 95% CI, −213.23 – (42.51), P=0.19).

Conclusion:

TXA reduced the volume of blood loss but did not reduce the need of blood transfusion.

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).

Prophylactic use of tranexamic acid for decreasing the blood loss in elective cesarean section: A placebo-controlled randomized clinical trial

INTRODUCTION

Tranexamic acid is used as a known treatment of post-partum hemorrhage both in natural vaginal deliveries and cesarean sections, but its use in elective cesarean as a prophylactic measure to decrease the blood loss is not so common.

OBJECTIVE

This clinical trial evaluates the efficacy and safety of tranexamic acid in decreasing the bleeding in women undergoing elective cesarean section.

METHOD

200 term singleton pregnant women who were scheduled for elective cesarean section were randomized to 2 groups and received a bolus of 1 gm tranexamic acid if body weight was <90 kg and 1.5 g if body weight was >90 kg diluted in 15 ml of 5% dextrose intravenously, or 5 ml of distilled water in 15 ml of 5% dextrose as placebo (before skin incision). Intra-operative and post-operative blood loss and hemoglobin levels were compared.

RESULTS

Tranexamic acid decreased the mean blood loss by 25.3 % in our studied women. Mean volume of intra-operative blood loss was 391.1 (±67.4) ml in tranexamic acid group and 523.8 (±153.4) ml in control group which was statistically significant lesser with a 132.7 ml difference. Rate of >1000 ml and >500 ml bleeding and need to blood transfusion were also statistically significant lower in tranexamic acid group., mean hemoglobin level was statistically significant lower in placebo group than tranexamic acid group (11.77 ± 0.50 versus 11.31 ± 0.56) 6 h after cesarean section. No adverse reaction was documented.

CONCLUSION

Prophylactic use of intravenous tranexamic acid decreases the blood loss safely in women undergoing elective cesarean section.

Blood loss and coagulation profile in pregnant and non-pregnant queens undergoing elective ovariohysterectomy

OBJECTIVES

The aims of this study were to determine if there is increased risk of intraoperative bleeding in pregnant cats undergoing elective ovariohysterectomy (OHE), and to compare coagulation in queens in various stages of estrus and pregnancy subjected to elective OHE using a whole-blood viscoelastic assay.

METHODS

Intraoperative blood loss was compared between non-pregnant and pregnant cats undergoing elective OHE. Viscoelastic evaluations of whole blood drawn pre- and postoperatively were performed using a point-of-care device measuring clot time (CT), clot formation time (CFT), alpha angle, maximum clot formation (MCF), amplitude at 10 and 20 mins (A10 and A20, respectively), and lysis index at 30 and 45 mins after MCF (LI30 and LI45, respectively).

RESULTS

One hundred and ninety-three cats underwent OHE by a ventral midline approach. Median blood loss was greater for pregnant cats (2.0 ml, range <0.5-13 ml) than non-pregnant cats (<0.5 ml, range <0.5-15 ml; P <0.0001). Preoperatively, pregnant cats had a shorter median CFT (165 s vs 190.5 s), increased median A10 (31 from 25.5 VCM units) and A20 (38 from 35 VCM units), and a lower median LI45 (99% from 100%) than non-pregnant cats. Postoperatively, A10 and A20 increased, and LI30 and LI45 decreased in both non-pregnant and pregnant queens. In pregnant queens, mean CT also increased postoperatively.

CONCLUSIONS AND RELEVANCE

Pregnant cats were relatively hypercoagulable and had an increased rate of clot lysis than non-pregnant cats. Intraoperative blood loss was increased in pregnant vs non-pregnant cats, but no clinically relevant bleeding conditions occurred.

Current Resources for Evidence-Based Practice, July 2020

An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of whether it is ethical not to offer doula care to all women, and commentaries on reviews focused on folic acid and autism spectrum disorder, and timing of influenza vaccination during pregnancy.