Tranexamic Acid for the Management of Obstetric Hemorrhage

Viscoelastic Testing in an Obstetric Population at High Risk of Hemorrhage

INTRODUCTION

Rotational thromboelastometry (ROTEM) is a point-of-care viscoelastic test used in trauma for goal-directed transfusion. However, there are limited data on baseline ROTEM parameters in the U.S. obstetric population. Obtaining baseline parameters is a first step in implementing a goal-directed massive transfusion protocol in obstetric hemorrhage.

OBJECTIVE

Our study aimed to establish pre- and postdelivery baseline parameters in a high-risk obstetric population and determine their association with postpartum hemorrhage (PPH).

STUDY DESIGN

Prospective observational study of patients ≥34 weeks' gestation, at high risk of PPH, admitted for delivery. INTEM, EXTEM, FIBTEM, and APTEM assays were performed at the time of admission to labor and delivery and then 2 hours after delivery. Primary outcome was pre- and postdelivery ROTEM parameters among women without PPH. A sample size of 60 women was needed for >90% power to detect at least 50% correlation between pre- and postdelivery assuming a loss of 10% of participants to follow-up.

RESULTS

Of 60 women in the study, 10 (17%) had PPH. Baseline characteristics were not different between those with or without PPH. Pre- and postdelivery ROTEM parameters were not significantly different except for APTEM. None of the patients who had PPH, compared with 4 (10%) of those who did not, had shortened clotting time and higher maximum clot firmness in postdelivery APTEM compared with EXTEM, a pattern suggestive of hyperfibrinolysis (p = 0.4).

CONCLUSION

In this study, we describe baseline ROTEM parameters in women at high risk of PPH. The majority of patients did not have a ROTEM pattern that is suggestive of hyperfibrinolysis, for which tranexamic acid is thought to be beneficial. Based on our findings, previously established obstetric transfusion thresholds for goal-directed massive transfusion protocols are likely valid for the majority of the obstetric population regardless of the presence of comorbidities or pregnancy complications.

KEY POINTS

· ROTEM parameters do not vary significantly before and after delivery.. · Most patients did not have a hyperfibrinolysis pattern, for which tranexamic acid is thought to be beneficial.. · Previous goal-directed obstetric transfusion thresholds are likely valid in most populations..

Recent research advances on polysaccharide-, peptide-, and protein-based hemostatic materials: A review

Hemorrhage is a potentially life-threatening emergency that can occur at any time or place. Whether traumatic, congenital, surgical, disease-related, or drug-induced, bleeding can lead to severe complications or death. Therefore, the development of efficient hemostatic materials is critical. However, the results and prognosis demonstrated by clinical means of hemostasis do not reach expectations. With the development of technology, novel hemostatic materials have been developed from polysaccharides (chitosan, hyaluronic acid, alginate, cellulose, cyclodextrins, starch, dextran, and carrageenan), peptides (self-assembling peptides), and proteins (silk fibroin, collagen, gelatin, keratin, and thrombin). These new materials exhibit high hemostatic efficacy due to the enhancement or interaction of various hemostatic mechanisms. The main forms include adhesives, sealants, bandages, hemostatic powders, and hemostatic sponges. This article introduces the clotting process and principles of hemostatic methods and reviews the research on polysaccharide-, peptide-, and protein-based hemostatic materials in the last five years. The design ideas and hemostatic principles of polysaccharide-, peptide-, and protein-based hemostatic materials are mainly introduced. Finally, we summarize material designs, advantages, disadvantages, and challenges regarding hemostatic materials.

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.

Blood Product Replacement for Postpartum Hemorrhage

Consideration for blood products replacement in postpartum hemorrhage should be given when blood loss exceeds 1.5 L or when an estimated 25% of blood has been lost. In cases of massive hemorrhage, standardized transfusion protocols have been shown to improve maternal morbidity and mortality. Most protocols recommend a balanced transfusion involving a 1:1:1 ratio of packed red blood cells, platelets, and fresh frozen plasma. Alternatives such as cryoprecipitate, fibrinogen concentrate, and prothrombin complex concentrates can be used in select clinical situations. Although transfusion of blood products can be lifesaving, it does have associated risks.

The Role of Perinatal Nurses in the Use of Tranexamic Acid During Postpartum Hemorrhage

Postpartum hemorrhage (PPH) is a leading cause of maternal morbidity and mortality worldwide. Mitigation of PPH is dependent on identification of risk, readiness, timely identification of hemorrhage, accurate determination of blood loss, and effective treatment. Perinatal nurses must be prepared to participate in all these aspects of care, including the use of tranexamic acid, an antifibrinolytic agent that has more recently been added to the pharmacologic agents used to reduce blood loss associated with hemorrhage. The purpose of this article is to identify the nurse's role in the management of PPH and to introduce the use of tranexamic acid in PPH management as part of the nurse's role in implementing best practices for PPH.

Anesthetic Management of a Patient With a Ruptured Heterotopic Pregnancy for Emergency Exploratory Laparotomy

Heterotopic pregnancy (HP) is an uncommon clinical condition characterized by the coexistence of intrauterine and extra-uterine pregnancies. HP is a diagnostic challenge as the typical methods for the early diagnosis of ectopic pregnancy are confounded by the simultaneous presence of intrauterine pregnancy (IUP). Ruptured HP is a potentially life-threatening obstetric emergency and can result in significant morbidity and mortality. Early diagnosis is the key to a favorable outcome. With the increasing number of patients undergoing artificial reproductive technology (ART), which is an important risk factor for HP, the odds of encountering HP patients are also growing. Anesthesiologists are challenged by the need to manage a bleeding obstetric patient while simultaneously ensuring the safety of the IUP. We present perioperative management of a patient with bleeding ruptured HP for emergency laparotomy who went on to have a successful twin delivery 37w3d via cesarean 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.

Bleeding Disorders in Primary Fibrinolysis

Fibrinolysis is a complex enzymatic process aimed at dissolving blood clots to prevent vascular occlusions. The fibrinolytic system is composed of a number of cofactors that, by regulating fibrin degradation, maintain the hemostatic balance. A dysregulation of fibrinolysis is associated with various pathological processes that result, depending on the type of abnormality, in prothrombotic or hemorrhagic states. This narrative review is focused on the congenital and acquired disorders of primary fibrinolysis in both adults and children characterized by a hyperfibrinolytic state with a bleeding phenotype.

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.

Assessment the role of tranexamic acid in prevention of postpartum hemorrhage

Background

Postpartum hemorrhage (PPH) is one of the leading causes of maternal mortality and morbidity worldwide. It is believed that hemostatic imbalance secondary to release of tissue plasminogen activator (tPA) and subsequent hyperfibrinolysis plays a major role in PPH pathogenesis. Antifibrinolytic drugs such as tranexamic acid (TXA) are widely used in hemorrhagic conditions associated with hyperfibrinolysis. TXA reduced maternal death due to PPH and its use as a part of PPH treatment is recommended, and in recent years, a number of trials have investigated the efficacy of prophylactic use of TXA in reducing the incidence and the severity of PPH.

The study is aiming to assess the efficacy of tranexamic acid in reducing blood loss throughout and after the lower segment cesarean section and reducing the risk of postpartum hemorrhage.

Results

The amount of blood loss was significantly lower in the study group than the control group (416.12±89.95 and 688.68±134.77 respectively). Also the 24-h postoperative hemoglobin was significantly higher in the study group (11.66±0.79 mg/dl) compared to the control group (10.53±1.07mg/dl), and the 24-h postoperative hematocrit value was significantly higher in the study group (34.99±2.40) compared to control (31.62±3.22).

Conclusion

Prophylactic administration of tranexamic acid reduces intraoperative and postoperative bleeding in cesarean section and the incidence of postpartum hemorrhage.

The value of the portable fibrinogen measuring device-a case report of severe postpartum hemorrhage with obstetric disseminated intravascular coagulation

Background

Fibrinogen concentration is an important indicator of the treatment for obstetric disseminated intravascular coagulation (DIC). We present how using the fibrinogen measuring device could solve problems in the treatment of postpartum hemorrhage with complicated DIC.

Case presentation

A 32-year-old woman with monochorionic diamniotic twins at 22 weeks of pregnancy was diagnosed with placental abruption and underwent emergent cesarean section. The estimated blood loss was 8375 g. She was transferred to our hospital for further treatment. Compressive uterine sutures and balloon tamponade were performed. We transfused fibrinogen and fresh frozen plasma actively during the operation to maintain plasma fibrinogen above 200 mg/dL by using a point-of-care fibrinogen measuring device. In spite of massive hemorrhage exceeding 10 L, she was extubated at the end of the operation and discharged on the 7th day after the operation.

Conclusion

The portable fibrinogen measuring device was useful for point-of-care assessment of obstetric DIC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40981-021-00426-y.

Effect of blood transfusion during cesarean section on postpartum hemorrhage in a tertiary hospital over a 4-year period

Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and death worldwide. The history of cesarean section and the occurrence of placenta previa were significantly associated with the increase in blood transfusion. Therefore, to prevent PPH, it is important to understand the effect of blood transfusion during cesarean section on postpartum hemorrhage. The purpose of this study is to determine the cause of blood transfusion during cesarean section, especially large amounts of blood transfusion, and to take measures to reduce the blood demand caused by PPH with limited blood supply.This study was a retrospective study of patients who underwent blood transfusion during cesarean section in Qilu Hospital of Shandong University (China) from January 2013 to December 2016. Red blood cell infusion ≥10 U during cesarean section was defined as massive blood transfusion. The study collected the demographics of pregnant women, obstetric characteristics and reasons for blood transfusions, as well as blood components and blood transfusion results. Multivariate regression analysis was performed for evaluating the risk factors of PPN.From 2013 to 2016, a total of 587 patients received blood transfusions during cesarean section. The proportion of women receiving blood transfusion during cesarean section increased (from 3.21% to 7.40%, P < .001). The history of cesarean section (P = .005) and the occurrence of placenta previa were positively correlated with the increase in blood transfusion (P = .016). There were 72 cases of massive blood transfusion, accounting for 12.27% of blood transfusion patients. Among mass blood transfusions, 93.1% of cases had prior cesarean delivery, and placenta previa accounted for 95.8%. 19.4% of patients receiving massive blood transfusions underwent hysterectomy. There was no significant difference in maternal BMI and gestational age between the mass blood transfusion group and the non-mass blood transfusion group.From 2013 to 2016, the demand for blood transfusion, especially the demand for massive blood transfusion, increased. Repeated cesarean section and placental previa combined with uterine scar are positively correlated with increased blood transfusion. Reducing the initial cesarean section should help reduce the massive blood transfusion caused by placenta previa with a history of cesarean section.

Management of Postabortion Complications for the Emergency Medicine Clinician

Although induced abortion is generally a safe outpatient procedure, many patients subsequently present to the emergency department, concerned about a postabortion complication. It is helpful for emergency physicians to understand the medications and procedures used in abortion care in the United States to effectively and efficiently triage and treat women presenting with potential complications from an abortion. Furthermore, because many states are experiencing increased abortion restrictions that limit access to care, emergency medicine physicians may encounter more patients presenting after self-managed abortions, which presents additional challenges. This article reviews the epidemiology and background of abortion care, including the range of symptoms and adverse effects that are within the scope of an uncomplicated procedure. This review also offers a comprehensive overview of management of abortion complications, including algorithms for more common complications and descriptions of less common but more severe adverse events. The article concludes with a recognition of the social stigma and legal regulations unique to abortion care.

Anesthesia for Obstetric Disasters

Over the past 30 years, maternal mortality has increased in the United States to 18 deaths per 100,000 live births. Obstetric emergencies, including hemorrhage, hypertensive disorders in pregnancy, HELLP syndrome, and amniotic fluid embolism, and anesthesia complications, including high neuraxial blockade, local anesthetic systemic toxicity, and the difficult obstetric airway, contribute to maternal cardiac arrest and maternal and fetal morbidity and mortality. Expeditious intervention by the obstetric anesthesiologist is critical in these emergent scenarios, and knowledge of best practices is essential to improve maternal and fetal outcomes.

Anesthesia for Obstetric Disasters

Over the past 30 years, maternal mortality has increased in the United States to 18 deaths per 100,000 live births. Obstetric emergencies, including hemorrhage, hypertensive disorders in pregnancy, HELLP syndrome, and amniotic fluid embolism, and anesthesia complications, including high neuraxial blockade, local anesthetic systemic toxicity, and the difficult obstetric airway, contribute to maternal cardiac arrest and maternal and fetal morbidity and mortality. Expeditious intervention by the obstetric anesthesiologist is critical in these emergent scenarios, and knowledge of best practices is essential to improve maternal and fetal outcomes.

Effect of Out-of-Hospital Tranexamic Acid vs Placebo on 6-Month Functional Neurologic Outcomes in Patients With Moderate or Severe Traumatic Brain Injury

IMPORTANCE

Traumatic brain injury (TBI) is the leading cause of death and disability due to trauma. Early administration of tranexamic acid may benefit patients with TBI.

OBJECTIVE

To determine whether tranexamic acid treatment initiated in the out-of-hospital setting within 2 hours of injury improves neurologic outcome in patients with moderate or severe TBI.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, double-blinded, randomized clinical trial at 20 trauma centers and 39 emergency medical services agencies in the US and Canada from May 2015 to November 2017. Eligible participants (N = 1280) included out-of-hospital patients with TBI aged 15 years or older with Glasgow Coma Scale score of 12 or less and systolic blood pressure of 90 mm Hg or higher.

INTERVENTIONS

Three interventions were evaluated, with treatment initiated within 2 hours of TBI: out-of-hospital tranexamic acid (1 g) bolus and in-hospital tranexamic acid (1 g) 8-hour infusion (bolus maintenance group; n = 312), out-of-hospital tranexamic acid (2 g) bolus and in-hospital placebo 8-hour infusion (bolus only group; n = 345), and out-of-hospital placebo bolus and in-hospital placebo 8-hour infusion (placebo group; n = 309).

MAIN OUTCOMES AND MEASURES

The primary outcome was favorable neurologic function at 6 months (Glasgow Outcome Scale-Extended score >4 [moderate disability or good recovery]) in the combined tranexamic acid group vs the placebo group. Asymmetric significance thresholds were set at 0.1 for benefit and 0.025 for harm. There were 18 secondary end points, of which 5 are reported in this article: 28-day mortality, 6-month Disability Rating Scale score (range, 0 [no disability] to 30 [death]), progression of intracranial hemorrhage, incidence of seizures, and incidence of thromboembolic events.

RESULTS

Among 1063 participants, a study drug was not administered to 96 randomized participants and 1 participant was excluded, resulting in 966 participants in the analysis population (mean age, 42 years; 255 [74%] male participants; mean Glasgow Coma Scale score, 8). Of these participants, 819 (84.8%) were available for primary outcome analysis at 6-month follow-up. The primary outcome occurred in 65% of patients in the tranexamic acid groups vs 62% in the placebo group (difference, 3.5%; [90% 1-sided confidence limit for benefit, -0.9%]; P = .16; [97.5% 1-sided confidence limit for harm, 10.2%]; P = .84). There was no statistically significant difference in 28-day mortality between the tranexamic acid groups vs the placebo group (14% vs 17%; difference, -2.9% [95% CI, -7.9% to 2.1%]; P = .26), 6-month Disability Rating Scale score (6.8 vs 7.6; difference, -0.9 [95% CI, -2.5 to 0.7]; P = .29), or progression of intracranial hemorrhage (16% vs 20%; difference, -5.4% [95% CI, -12.8% to 2.1%]; P = .16).

CONCLUSIONS AND RELEVANCE

Among patients with moderate to severe TBI, out-of-hospital tranexamic acid administration within 2 hours of injury compared with placebo did not significantly improve 6-month neurologic outcome as measured by the Glasgow Outcome Scale-Extended.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01990768.

Nebulized tranexamic acid for recurring hemoptysis in critically ill patients: case series

BACKGROUND

Hemoptysis is a clinical condition encountered in the emergency department (ED) and must be managed and investigated urgently to maintain the patient's hemostasis. The management of hemoptysis depends on treating the underlying cause. Tranexamic acid (TXA) is an anti-fibrinolytic drug used to systemically control bleeding. There are a few studies available that investigate the use of nebulized tranexamic acid for hemoptysis with contradictory results. Our paper demonstrates three cases where patients presented with significant hemoptysis and had significant improvement in symptoms following the administration of nebulized tranexamic acid. The overall need for blood transfusion was reduced.

RESULTS

Three patients presented to the emergency room for evaluation of hemoptysis. All three patients had different underlying pathologies resulting in their hemoptysis and were monitored in the ICU. Initial conventional medical therapies including the correction of coagulopathy and discontinuing offending agents were utilized for treatment. After persistent symptoms, nebulized TXA at a dose of 500 mg three times a day was administered. The patients were all discharged from the hospital with improvement in their symptoms.

CONCLUSION

Tranexamic acid may be considered in the treatment of hemoptysis regardless of the underlying cause. This may be utilized pending further workup and investigation into the underlying source of the bleeding.

Damage-control resuscitation in obstetrics

Severe obstetric hemorrhage is a catastrophic event and represents the main cause of maternal morbidity and mortality worldwide. The elevated mortality rate due to hemorrhage is associated with metabolic complications and organ hypoperfusion that may trigger a state of irreversible coagulopathy. Thus, the use of conventional measures to control bleeding frequently generates a vicious cycle in which the patient continues bleeding (prolonging surgical times). Damage-control surgery has proven to be feasible and effective in the context of obstetric hemorrhage. It combines surgical and resuscitative measures that generate successful results in the control of refractory bleeding, ultimately decreasing mortality in patients being in critical condition.

Next Generation Medical Management of Postpartum Hemorrhage

BACKGROUND

Postpartum hemorrhage remains a significant contributor to morbidity and mortality of women of childbearing age worldwide. Trends in both incidence and severity of postpartum hemorrhage are increasing which makes it imperative to identify drugs that could target prevention and/or treatment of these postpartum hemorrhages for women living in high, middle and low-income countries.

METHODS

We have reviewed current advances in the medical management of postpartum hemorrhage focusing on non-uterotonic therapy. We specifically describe the use and mechanism of action of tranexamic acid (TXA) and fibrinogen concentrate. Furthermore, we address the existing data for using these medications in postpartum hemorrhage, highlighting both strengths and limitations.

RESULTS

This review describes a new generation of medications that are promising for the prevention and/or treatment of postpartum hemorrhage. For patients at risk for significant hemorrhage, TXA has been shown to reduce intraoperative blood loss and can be given as a prophylactic agent. For the treatment of postpartum hemorrhage, early use of TXA has the potential to reduce mortality. In addition, some data exists supporting the use of fibrinogen concentrate, though more studies are required to help formulate guidelines for its use.

CONCLUSION

A promising new approach for the management of severe postpartum hemorrhage is using medications that alter coagulation. More data are needed to describe ideal patient populations, dosing, the time of administration, and infusion rate.

Blood Products in the Management of Abnormal Placentation

A critical tool in the successful management of patients with abnormal placentation is an established massive transfusion protocol designed to rapidly deliver blood products in obstetrical and surgical hemorrhage. Spurred by trauma research and an understanding of consumptive coagulopathy, the past 2 decades have seen a shift in volume resuscitation from an empiric, crystalloid-based method to balanced, targeted transfusion therapy. The present article reviews patient blood management in abnormal placentation, beginning with optimizing the patient's status in the antenatal period to the laboratory assessment and transfusion strategy for blood products at the time of hemorrhage.

Trauma in Pregnancy

Although trauma in pregnancy is rare, it is one of the most common causes of morbidity and mortality to pregnant women and fetus. Pathophysiology of trauma is generally time sensitive, and this is still true in pregnant patients, with the additional challenge of rare presentation and balancing the management of two patients concurrently. Successful resuscitation requires understanding the physiologic changes to the woman throughout the course of pregnancy. Ultimately, trauma management is best approached by prioritizing maternal resuscitation.

No effect of tranexamic acid on platelet function and thrombin generation (ETAPlaT) in postpartum haemorrhage: a randomised placebo-controlled trial

Background: Postpartum hemorrhage (PPH) is a leading cause of maternal mortality and morbidity. The WOMAN trial showed that tranexamic acid (TXA) reduces death due to bleeding in women with PPH. To determine whether TXA has pro-thrombotic effects in women with PPH, we measured endogenous thrombin potential (ETP), coagulation factors V, VIII, von Willebrand (vW), fibrinogen, D-Dimers and platelet function. Methods: We conducted a sub-study within the WOMAN trial, an international randomized, parallel-group, double blind, placebo-controlled trial. Women with primary PPH were randomly allocated to receive 1 gram of tranexamic acid or matching placebo. Baseline blood samples were collected just prior to the first dose and a follow up sample was collected 30±15 minutes afterwards. We compared before and after changes in coagulation parameters between treatment groups using repeated measurement ANOVA. Change in ETP was the primary outcome. We did an intention-to-treat analysis using ANCOVA with adjustment for baseline and the time interval between the blood samples. Findings: A total of 187 patients were randomized to receive TXA (n=93) or matching placebo (n=94). Six patients were excluded due to incomplete data. The reduction in ETP from baseline to follow up was 43.2 nM*min (95%CI, -16.6 to 103.1) in the TXA group and 4.6 nM*min (95%CI, -51.4 to 60.6) in the placebo group. The difference was not statistically significant (95%CI, -42.9 to 120). There were no significant effects of TXA treatment on any other parameters (ADPtest, TRAPtest, coagulation factors activity, fibrinogen levels, D-Dimer level). Conclusion: We found no evidence that tranexamic acid treatment for PPH has substantial pro-coagulant effects. However, larger studies are needed to confirm or refute more modest effects. Trial registration: ISRCTN76912190 (initially registered 10/12/2008, WOMAN-ETAPlat included on 28/10/2013) and NCT00872469 (initially registered 31/03/2009, WOMAN-ETAPlat included on 28/10/2013).

Placenta Accreta Spectrum

Placenta accreta spectrum, formerly known as morbidly adherent placenta, refers to the range of pathologic adherence of the placenta, including placenta increta, placenta percreta, and placenta accreta. The most favored hypothesis regarding the etiology of placenta accreta spectrum is that a defect of the endometrial-myometrial interface leads to a failure of normal decidualization in the area of a uterine scar, which allows abnormally deep placental anchoring villi and trophoblast infiltration. Maternal morbidity and mortality can occur because of severe and sometimes life-threatening hemorrhage, which often requires blood transfusion. Although ultrasound evaluation is important, the absence of ultrasound findings does not preclude a diagnosis of placenta accreta spectrum; thus, clinical risk factors remain equally important as predictors of placenta accreta spectrum by ultrasound findings. There are several risk factors for placenta accreta spectrum. The most common is a previous cesarean delivery, with the incidence of placenta accreta spectrum increasing with the number of prior cesarean deliveries. Antenatal diagnosis of placenta accreta spectrum is highly desirable because outcomes are optimized when delivery occurs at a level III or IV maternal care facility before the onset of labor or bleeding and with avoidance of placental disruption. The most generally accepted approach to placenta accreta spectrum is cesarean hysterectomy with the placenta left in situ after delivery of the fetus (attempts at placental removal are associated with significant risk of hemorrhage). Optimal management involves a standardized approach with a comprehensive multidisciplinary care team accustomed to management of placenta accreta spectrum. In addition, established infrastructure and strong nursing leadership accustomed to managing high-level postpartum hemorrhage should be in place, and access to a blood bank capable of employing massive transfusion protocols should help guide decisions about delivery location.

Tranexamic Acid for the Prevention of Blood Loss after Vaginal Delivery

BACKGROUND

The use of tranexamic acid reduces mortality due to postpartum hemorrhage. We investigated whether the prophylactic administration of tranexamic acid in addition to prophylactic oxytocin in women with vaginal delivery would decrease the incidence of postpartum hemorrhage.

METHODS

In a multicenter, double-blind, randomized, controlled trial, we randomly assigned women in labor who had a planned vaginal delivery of a singleton live fetus at 35 or more weeks of gestation to receive 1 g of tranexamic acid or placebo, administered intravenously, in addition to prophylactic oxytocin after delivery. The primary outcome was postpartum hemorrhage, defined as blood loss of at least 500 ml, measured with a collector bag.

RESULTS

Of the 4079 women who underwent randomization, 3891 had a vaginal delivery. The primary outcome occurred in 156 of 1921 women (8.1%) in the tranexamic acid group and in 188 of 1918 (9.8%) in the placebo group (relative risk, 0.83; 95% confidence interval [CI], 0.68 to 1.01; P=0.07). Women in the tranexamic acid group had a lower rate of provider-assessed clinically significant postpartum hemorrhage than those in the placebo group (7.8% vs. 10.4%; relative risk, 0.74; 95% CI, 0.61 to 0.91; P=0.004; P=0.04 after adjustment for multiple comparisons post hoc) and also received additional uterotonic agents less often (7.2% vs. 9.7%; relative risk, 0.75; 95% CI, 0.61 to 0.92; P=0.006; adjusted P=0.04). Other secondary outcomes did not differ significantly between the two groups. The incidence of thromboembolic events in the 3 months after delivery did not differ significantly between the tranexamic acid group and the placebo group (0.1% and 0.2%, respectively; relative risk, 0.25; 95% CI, 0.03 to 2.24).

CONCLUSIONS

Among women with vaginal delivery who received prophylactic oxytocin, the use of tranexamic acid did not result in a rate of postpartum hemorrhage of at least 500 ml that was significantly lower than the rate with placebo. (Funded by the French Ministry of Health; TRAAP ClinicalTrials.gov number, NCT02302456 .).

Management of postpartum hemorrhage: how to improve maternal outcomes?

Postpartum hemorrhage is the leading cause of maternal mortality and severe morbidity. Despite efforts to improve maternal outcomes, management of postpartum hemorrhage still faces at least four challenges, discussed in this review. First, current definitions for severe postpartum hemorrhage hamper early identification of women with a high risk of adverse outcomes. Adaptations to the definitions and the use of clinical tools such as shock index and early warning systems may facilitate this early identification. Second, surgical and radiological interventions to prevent hysterectomy are not always successful. More knowledge on the influence of patient and bleeding characteristics on the success rates of these interventions is necessary. Scarce data suggest that early timing of intrauterine balloon tamponade may improve maternal outcomes, whereas early timing of arterial embolization seems to be unrelated to maternal outcomes. Third, fluid resuscitation with crystalloids and colloids is unavoidable in the early phases of postpartum hemorrhage but may result in dilutional coagulopathy. Effects of different volumes of clear fluids on the occurrence of dilutional coagulopathy and maternal outcomes is unknown. Fourth, a better understanding of diagnosis and correction of coagulopathy during postpartum hemorrhage is needed. Low plasma fibrinogen levels at the start of postpartum hemorrhage predict progression to severe hemorrhage, but standard coagulation screens are time consuming. A solution may be point-of-care coagulation testing; however, clinical usefulness during postpartum hemorrhage has not been demonstrated. To date, early administration of tranexamic acid is the only hemostatic intervention that was proven to improve outcomes in women with postpartum hemorrhage.

Primary hyperfibrinolysis: Facts and fancies

Fibrinolysis is a complex process that controls both hemostasis and thrombosis. The regulation of the fibrinolytic system is mediated through a wide array of cofactors and inhibitors that maintain the hemostatic balance in a delicate equilibrium. As a consequence, disturbances in the fibrinolysis pathway are associated with various disease states, ranging from thrombotic to hemorrhagic clinical phenotypes. In particular, a number of inherited and acquired disorders are associated with an enhanced fibrinolysis leading to a bleeding tendency that in some cases may be life-threatening. Hyperfibrinolysis has been classified into primary and secondary forms but such differentiation, which may have important treatment implications, is still controversial. This narrative review will be focused on inherited and acquired conditions associated with primary hyperfibrinolysis.