Haemostatic management of obstetric haemorrhage

Fibrinogen as a potential diagnostic marker for prediction and evaluation of postpartum hemorrhage: a retrospective study

OBJECTIVE

To investigate whether prenatal fibrinogen (FIB) or other related factors could be utilized to evaluate the risk of postpartum hemorrhage (PPH).

METHODS

A retrospective study was conducted in a database from January 2015 to December 2019. A total of 128 patients were enrolled and evaluated with FIB, in which 55 patients were assigned to low FIB and 73 in normal FIB.

RESULTS

According to the volume of blood loss, the mean of the low FIB group (<4 g/L) was markedly higher than that of the normal FIB group (≥4 g/L). Prenatal FIB was negatively correlated with PPH volume. The receiver operating characteristic (ROC) curve results indicated that the value of prenatal FIB was 0.701 to predict refractory PPH.

CONCLUSIONS

Prenatal FIB was significantly related to thrombin time (TT), which may be an independent factor to predict the coagulation state of prenatal pregnancy.

Analysis of a 5-year, evidenced-based, rational blood utilisation project in a South African regional hospital

BACKGROUND

Blood products are a lifesaving but limited resource, particularly in resource-limited settings. Evidence-based transfusion criteria tailored to local hospitals have shown great promise in reducing costs, minimising shortages, and ameliorating the morbidity and mortality associated with liberal blood product usage. We implemented the "Saving Blood, Saving Lives" project to: promote responsible blood product use and reduce blood product ordering inefficiencies and expenditure.

METHODS

A comprehensive change management programme, preceded by 3 months of clinical department consultation and training, was implemented. A new evidence-based protocol for blood product utilisation was developed, together with an accountability form. This form was used in monthly audit meetings to refine policies, identify new problems, improve communication, and to drive hospital staff accountability and training. The primary measure of the programme's success was the change in the number of red cell concentrate units ordered.

RESULTS

Project implementation required minimal time and no additional budget or staff. Annual red cell concentrate usage reduced from 7211 units in year one to 4077 units in year 5 (p < 0.001). Similar reductions were seen in freeze-dried plasma and platelet usage, as well as administrative costs. Total project saving, adjusted to baseline admission numbers, amounted to over R46 million ($2.5 million).

CONCLUSIONS

As a change management programme centred the "Saving Blood, Saving Lives" project, was able to significantly reduce blood product-related administration and expenditure by implementing evidence-based transfusion criteria. The programme is simple, replicable and cost effective, making it ideally suited for use in resource-constrained environments.

[Postpartum Hemorrhage]

Postpartum hemorrhage (PPH) affects about 4% of all deliveries in high-income countries and continues to rise, a trend attributable to the increase in caesarean section rates and maternal morbidity. Preventive measures such as the precautionary administration of uterotonics effectively reduce the risk of severe bleeding irrespective of birth mode. As a time-critical condition and a significant contributor to adverse maternal outcomes, PPH needs to be diagnosed early by measuring, not estimating, blood losses. Institutional treatment algorithms should be available to guide stage-based interdisciplinary management without delay. The main therapy goals are to identify the etiology and stop the bleeding by using uterotonics and mechanical and surgical interventions, to restore hemodynamic stability by volume and transfusion therapy and to optimize hemostasis by laboratory- and viscoelastic assay-guided factor replacement. This review highlights current recommendations for prevention, diagnosis and treatment of PPH.

Comparison of H-Hayman uterine compression suture with conventional vertical sutures: A cross-sectional study in a tertiary center

OBJECTIVE

To compare H-Hayman, a modified uterine compression suturing technique (UCS) that we describe for the first time in the literature, with conventional vertical UCS techniques.

METHODS

The H-Hayman technique was used in 14 women and the conventional UCS technique in 21 women. In order to provide standardization in the study, only patients who had developed upper-segment atony during cesarean section were recruited for the study.

RESULTS

Bleeding control was achieved in 85.7% (12/14) of the cases using the H-Hayman technique. In the remaining two patients with persistent hemorrhage in this group, bleeding control was provided with bilateral uterine artery ligation, and a hysterectomy was avoided in all cases. With the conventional technique, bleeding control was achieved in 76.1% (16/21) of the patients, and the overall success rate was 95.2% after bilateral uterine artery ligation in those with persistent hemorrhage. In addition, the estimated blood loss and the need for erythrocyte suspension transfusion were significantly lower in the H-Hayman group (P = 0.01 and P = 0.04, respectively).

CONCLUSION

We found the H-Hayman technique to be at least as successful as conventional UCS. In addition, patients who underwent suturing with the H-Hayman technique had less blood loss and a lower requirement for erythrocyte suspension transfusion.

Coagulation management and transfusion in massive postpartum hemorrhage

PURPOSE OF REVIEW

Excessive bleeding during and following childbirth remains one of the leading causes of maternal mortality.

RECENT FINDINGS

Current guidelines differ in definitions and recommendations on managing transfusion and hemostasis in massive postpartum hemorrhage (PPH). Insights gained from trauma-induced coagulopathy are not directly transferable to the obstetric population due to gestational alterations and a differing pathophysiology.

SUMMARY

Factor deficiency is uncommon at the beginning of most etiologies of PPH but will eventually develop from consumption and depletion in the absence of bleeding control. The sensitivity of point-of-care tests for fibrinolysis is too low and may delay treatment, therefore tranexamic acid should be started early at diagnosis even without signs for hyperfibrinolysis. Transfusion management may be initiated empirically, but is best to be guided by laboratory and viscoelastic assay results as soon as possible. Hypofibrinogenemia is well detected by point-of-care tests, thus substitution may be tailored to individual needs, while reliable thresholds for fresh frozen plasma (FFP) and specific components are yet to be defined. In case of factor deficiency, prothrombin complex concentrate or lyophilized plasma allow for a more rapid restoration of coagulation than FFP. If bleeding and hemostasis are under control, a timely anticoagulation may be necessary.

Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022

BACKGROUND

Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management.

DESIGN

A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline.

RESULTS

These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%.

DISCUSSION

Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality.

CONCLUSION

All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Building the foundation for a community-generated national research blueprint for inherited bleeding disorders: research to advance the health of people with inherited bleeding disorders with the potential to menstruate

BACKGROUND

People who have or had the potential to menstruate (PPM) with inherited bleeding disorders (BD) face particular challenges receiving appropriate diagnosis and care and participating in research. As part of an initiative to create a National Research Blueprint for future decades of research, the National Hemophilia Foundation (NHF) and American Thrombosis and Hemostasis Network conducted extensive all-stakeholder consultations to identify the priorities of PPM with inherited BDs and those who care for them.

RESEARCH DESIGN AND METHODS

Working group (WG) 4 of the NHF State of the Science Research Summit distilled community-identified priorities for PPM with inherited BDs into concrete research questions and scored their feasibility, impact, and risk.

RESULTS

WG4 identified important gaps in the foundational knowledge upon which to base optimal diagnosis and care for PPM with inherited BDs. They defined 44 top-priority research questions concerning lifespan sex biology, pregnancy and the post-partum context, uterine physiology and bleeding, bone and joint health, health care delivery, and patient-reported outcomes and quality-of-life.

CONCLUSIONS

The needs of PPM will best be advanced with research designed across the spectrum of sex and gender biology, with methodologies and outcome measures tailored to this population, involving them throughout.

Anaesthetic management of cerebral arteriovenous malformation hemorrhage during pregnancy: A case series

RATIONALE

There is no clear consensus guidance for anesthesiologists on how to manage patients with cerebral arteriovenous malformation (cAVM) rupture and hemorrhage during pregnancy who need craniotomy. Our objective was to review the anesthesia management of pregnant women who underwent resection of cAVM at our institution and to provide opinions and suggestions.

PATIENT CONCERNS

Herein, we report of 3 patients with cAVM rupture and hemorrhage during pregnancy who underwent neurosurgery at the 22nd, 28th, and 20th weeks of pregnancy.

DIAGNOSES

All 3 patients were admitted to the emergency department of our hospital due to sudden symptoms. Subsequently, their head imaging results confirmed the rupture and hemorrhage of cAVM. The rupture and hemorrhage of cAVM during pregnancy has a low incidence and high mortality, which seriously endangers the safety of the mother and fetus. For this emergency condition, craniotomy for removing intracranial lesions and clear hematoma can result in a chance of a successful delivery. Especially in the second and third trimesters of pregnancy, the management goal of anesthesia is to ensure the maternofetal safety and to maintain continuous pregnancy.

INTERVENTIONS

This article describes the process of intraoperative anesthesia management and maternal-fetal outcomes and discusses the key issues for the anesthesia management of cAVM rupture during pregnancy, including considerations of physiological changes during pregnancy and anesthesia medication, intraoperative monitoring, the maintenance of hemodynamic stability, and the control of intracranial pressure, among other considerations. Resection of intracranial lesions should be performed whenever possible while maintaining the pregnancy for better maternal and infant outcomes.

OUTCOMES

The operations of the 3 pregnant women were successfully completed under our detailed anesthesia planning and careful anesthesia management. All the patients recovered well after the operation, and underwent cesarean section to give birth smoothly.

LESSONS

The preservation of pregnancy under cAVM resection is a complex challenge for anesthesiologists, and these 3 cases provide an extensive amount of experience for anesthesia management in similar situations. Detailed anesthesia planning and careful anesthesia management by anesthesiologists are important guarantees for good maternal and fetal outcomes.

Haemostatic support in postpartum haemorrhage: A review of the literature and expert opinion

Postpartum haemorrhage (PPH) remains the leading cause of pregnancy-related deaths worldwide. Typically, bleeding is controlled by timely obstetric measures in parallel with resuscitation and treatment of coagulopathy. Early recognition of abnormal coagulation is crucial and haemostatic support should be considered simultaneously with other strategies as coagulopathies contribute to the progression to massive haemorrhage. However, there is lack of agreement on important topics in the current guidelines for management of PPH. A clinical definition of PPH is paramount to understand the situation to which the treatment recommendations relate; however, reaching a consensus has previously proven difficult. Traditional definitions are based on volume of blood loss, which is difficult to monitor, can be misleading and leads to treatment delay. A multidisciplinary approach to define PPH considering vital signs, clinical symptoms, coagulation and haemodynamic changes is needed. Moreover, standardised algorithms or massive haemorrhage protocols should be developed to reduce the risk of morbidity and mortality and improve overall clinical outcomes in PPH. If available, point-of-care testing should be used to guide goal-directed haemostatic treatment. Tranexamic acid should be administered as soon as abnormal bleeding is recognised. Fibrinogen concentrate rather than fresh frozen plasma should be administered to restore haemostasis where there is elevated risk of fibrinogen deficiency (e.g., in catastrophic bleeding or in cases of abruption or amniotic fluid embolism) as it is a more concentrated source of fibrinogen. Lastly, organisational considerations are equally as important as clinical interventions in the management of PPH and have the potential to improve patient outcomes.

Major haemorrhage: past, present and future

Major haemorrhage is a leading cause of morbidity and mortality worldwide. Successful treatment requires early recognition, planned responses, readily available resources (such as blood products) and rapid access to surgery or interventional radiology. Major haemorrhage is often accompanied by volume loss, haemodilution, acidaemia, hypothermia and coagulopathy (factor consumption and fibrinolysis). Management of major haemorrhage over the past decade has evolved to now deliver a 'package' of haemostatic resuscitation including: surgical or radiological control of bleeding; regular monitoring of haemostasis; advanced critical care support; and avoidance of the lethal triad of hypothermia, acidaemia and coagulopathy. Recent trial data advocate for a more personalised approach depending on the clinical scenario. Fresh frozen plasma should be given as early as possible in major trauma in a 1:1 ratio with red blood cells until the results of coagulation tests are available. Tranexamic acid is a cheap, life-saving drug and is advocated in major trauma, postpartum haemorrhage and surgery, but not in patients with gastrointestinal bleeding. Fibrinogen levels should be maintained > 2 g.l^-1 in postpartum haemorrhage and > 1.5 g.l^-1 in other haemorrhage. Improving outcomes after major traumatic haemorrhage is now driving research to include extending blood-product resuscitation into prehospital care.

SHock-INduced Endotheliopathy (SHINE): A mechanistic justification for viscoelastography-guided resuscitation of traumatic and non-traumatic shock

Irrespective of the reason for hypoperfusion, hypocoagulable and/or hyperfibrinolytic hemostatic aberrancies afflict up to one-quarter of critically ill patients in shock. Intensivists and traumatologists have embraced the concept of SHock-INduced Endotheliopathy (SHINE) as a foundational derangement in progressive shock wherein sympatho-adrenal activation may cause systemic endothelial injury. The pro-thrombotic endothelium lends to micro-thrombosis, enacting a cycle of worsening perfusion and increasing catecholamines, endothelial injury, de-endothelialization, and multiple organ failure. The hypocoagulable/hyperfibrinolytic hemostatic phenotype is thought to be driven by endothelial release of anti-thrombogenic mediators to the bloodstream and perivascular sympathetic nerve release of tissue plasminogen activator directly into the microvasculature. In the shock state, this hemostatic phenotype may be a counterbalancing, yet maladaptive, attempt to restore blood flow against a systemically pro-thrombotic endothelium and increased blood viscosity. We therefore review endothelial physiology with emphasis on glycocalyx function, unique biomarkers, and coagulofibrinolytic mediators, setting the stage for understanding the pathophysiology and hemostatic phenotypes of SHINE in various etiologies of shock. We propose that the hyperfibrinolytic phenotype is exemplified in progressive shock whether related to trauma-induced coagulopathy, sepsis-induced coagulopathy, or post-cardiac arrest syndrome-associated coagulopathy. Regardless of the initial insult, SHINE appears to be a catecholamine-driven entity which early in the disease course may manifest as hyper- or hypocoagulopathic and hyper- or hypofibrinolytic hemostatic imbalance. Moreover, these hemostatic derangements may rapidly evolve along the thrombohemorrhagic spectrum depending on the etiology, timing, and methods of resuscitation. Given the intricate hemochemical makeup and changes during these shock states, macroscopic whole blood tests of coagulative kinetics and clot strength serve as clinically useful and simple means for hemostasis phenotyping. We suggest that viscoelastic hemostatic assays such as thromboelastography (TEG) and rotational thromboelastometry (ROTEM) are currently the most applicable clinical tools for assaying global hemostatic function-including fibrinolysis-to enable dynamic resuscitation with blood products and hemostatic adjuncts for those patients with thrombotic and/or hemorrhagic complications in shock states.

Point-of-care coagulation testing for postpartum haemorrhage

The use of viscoelastic haemostatic assays (VHAs) to guide blood product replacement during postpartum haemorrhage is expanding. Rotem and TEG devices can be used to detect and treat clinically significant hypofibrinogenaemia, although evidence to support the role of VHAs for guiding fresh frozen plasma and platelet transfusion is less clear. If Rotem/TEG traces are normal, clinicians should investigate for another cause of bleeding, and haemostatic support is not required. Guidelines support the use of VHAs during postpartum haemorrhage as part of locally agreed algorithms. There is a wide consensus that fibrinogen replacement is needed if the Fibtem A5 is <12 mm and if there is ongoing bleeding. Guidelines recommend against using VHAs to guide tranexamic acid infusion, and this drug should be given as soon as bleeding is recognised, irrespective of the Rotem/TEG traces. The cost-effectiveness of VHAs during postpartum haemorrhage needs to be addressed.

Epidemiology and definition of PPH worldwide

Postpartum/peripartum hemorrhage (PPH) is an obstetric emergency complicating 1-10% of all deliveries and is a leading cause of maternal mortality and morbidity worldwide. However, the incidence of PPH differs widely according to the definition and criteria used, the way of measuring postpartum blood loss, and the population being studied with the highest numbers in developing countries. Despite all the significant progress in healthcare, the incidence of PPH is rising due to an incomplete implementation of guidelines, resulting in treatment delays and suboptimal care. A consensus clinical definition of PPH is needed to enable awareness, early recognition, and initiation of appropriate intensive treatment. Unfortunately, the most used definition of PPH based on blood loss ≥500 ml after delivery suffers from inaccuracies in blood loss quantification and is not clinically relevant in most cases, as the amount of blood loss does not fully reflect the severity of bleeding.

The Choice between Plasma-Based Common Coagulation Tests and Cell-Based Viscoelastic Tests in Monitoring Hemostatic Competence: Not an either-or Proposition

There has been a significant interest in the last decade in the use of viscoelastic tests (VETs) to determine the hemostatic competence of bleeding patients. Previously, common coagulation tests (CCTs) such as the prothrombin time (PT) and partial thromboplastin time (PTT) were used to assist in the guidance of blood component and hemostatic adjunctive therapy for these patients. However, the experience of decades of VET use in liver failure with transplantation, cardiac surgery, and trauma has now spread to obstetrical hemorrhage and congenital and acquired coagulopathies. Since CCTs measure only 5 to 10% of the lifespan of a clot, these assays have been found to be of limited use for acute surgical and medical conditions, whereby rapid results are required. However, there are medical indications for the PT/PTT that cannot be supplanted by VETs. Therefore, the choice of whether to use a CCT or a VET to guide blood component therapy or hemostatic adjunctive therapy may often require consideration of both methodologies. In this review, we provide examples of the relative indications for CCTs and VETs in monitoring hemostatic competence of bleeding patients.

Hemostatic Effects of Tranexamic Acid in Cesarean Delivery: An Ancillary Study of the TRAAP2 Study

BACKGROUND

 Fibrinolysis activation during delivery contributes to postpartum hemorrhage (PPH). Clot lysis time studied with the global fibrinolytic capacity device (GFC/LT) is a functional test which rapidly assesses fibrinolytic profile. Tranexamic acid (TXA) is an efficient antifibrinolytic therapy.

METHODS

 We prospectively studied fibrinolysis and coagulation in 33 women included in the TRAAP2 trial, which aimed to assess the impact of TXA in preventing PPH following a cesarean delivery. TXA or placebo was randomly administered after childbirth as part of the TRAAP2 trial's protocol. Fibrinolytic (GFC/LT, plasma concentration of fibrinolysis activators and inhibitors) and hemostatic parameters were assayed at three sample times (TREF [T-reference] after anesthesia, T15 and T120minutes after TXA, or placebo administration).

RESULTS

 All cesarean deliveries were elective. In the placebo group, the clot lysis time assessed with GFC/LT significantly decreased between TREF and T120, indicating an activated fibrinolysis (44 [interquartile range, IQR: 40-48] vs. 34 [IQR: 30-36] minutes, p<0.001). In both TXA and placebo groups, significant fluctuations of the plasmatic concentrations of fibrinolytic mediators were noticed over time, suggesting fibrinolysis activation. Clot lysis time measured by GFC/LT was significantly increased in women of the TXA group as compared with those in the placebo group at T15 (120 [120-120] vs. 36 [34-41] minutes, p<0.001) and T120minutes (113 [99-120] vs. 34 [30-36] minutes, p<0.001) after drug administration, indicating a decreased in fibrinolysis in those women.

CONCLUSIONS

 GFC/LT evidenced fibrinolysis activation during cesarean delivery, linked to a decrease in fibrinolytic inhibitors. GFC/LT revealed a significant antifibrinolytic effect of TXA compared with placebo.

Latest advances in postpartum hemorrhage management

Hemorrhage is the leading cause of maternal mortality worldwide. A maternal health priority is improving how healthcare providers prevent and manage postpartum hemorrhage (PPH). Because anesthesiologists can help facilitate how hospitals develop approaches for PPH prevention and anticipatory planning, we review the potential utility of PPH risk-assessment tools, bundles, and protocols. Anesthesiologists rely on clinical and diagnostic information for initiating and evaluating medical management. Therefore, we review modalities for measuring blood loss after delivery, which includes visual, volumetric, gravimetric, and colorimetric approaches. Point-of-care technologies for assessing changes in central hemodynamics (ultrasonography) and coagulation profiles (rotational thromboelastometry and thromboelastography) are also discussed. Anesthesiologists play a critical role in the medical and transfusion management of PPH. Therefore, we review blood ordering and massive transfusion protocols, fixed-ratio vs. goal-directed transfusion approaches, coagulation changes during PPH, and the potential clinical utility of the pharmacological adjuncts, tranexamic acid, and fibrinogen concentrate.

DIC in Pregnancy - Pathophysiology, Clinical Characteristics, Diagnostic Scores, and Treatments

Obstetrical hemorrhage and especially DIC (disseminated intravascular coagulation) is a leading cause for maternal mortality across the globe, often secondary to underlying maternal and/or fetal complications including placental abruption, amniotic fluid embolism, HELLP syndrome (hemolysis, elevated liver enzymes and low platelets), retained stillbirth and acute fatty liver of pregnancy. Various obstetrical disorders can present with DIC as a complication; thus, increased awareness is key to diagnosing the condition. DIC patients can present to clinicians who may not be experienced in a variety of aspects of thrombosis and hemostasis. Hence, DIC diagnosis is often only entertained when the patient already developed uncontrollable bleeding or multi-organ failure, all of which represent unsalvageable scenarios. Beyond the clinical presentations, the main issue with DIC diagnosis is in relation to coagulation test abnormalities. It is widely believed that in DIC, patients will have prolonged prothrombin time (PT) and partial thromboplastin time (PTT), thrombocytopenia, low fibrinogen, and raised D-dimers. Diagnosis of DIC can be elusive during pregnancy and requires vigilance and knowledge of the physiologic changes during pregnancy. It can be facilitated by using a pregnancy specific DIC score including three components: 1) fibrinogen concentrations; 2) the PT difference - relating to the difference in PT result between the patient's plasma and the laboratory control; and 3) platelet count. At a cutoff of ≥26 points, the pregnancy specific DIC score has 88% sensitivity, 96% specificity, a positive likelihood ratio (LR) of 22, and a negative LR of 0.125. Management of DIC during pregnancy requires a prompt attention to the underlying condition leading to this complication, including the delivery of the patient, and correction of the hemostatic problem that can be guided by point of care testing adjusted for pregnancy.

Nonovert disseminated intravascular coagulation (DIC) in pregnancy: a new scoring system for the identification of patients at risk for obstetrical hemorrhage requiring blood product transfusion

BACKGROUND

Nonovert disseminated intravascular coagulation (DIC) is a subclinical hemostatic dysfunction that has not yet reached the decompensation stage. The detection of pregnant patients at this stage may assist in the identification of those who will develop severe obstetrical hemorrhage, as it is one of the leading causes for preventable maternal mortality. Currently, nonovert DIC is diagnosed by a scoring system based on nonpregnant patients, originally generated by the International Society on Thrombosis and Hemostasis (ISTH), which does not address the physiologic changes of the hemostatic system during pregnancy.

OBJECTIVES

(1) To develop a pregnancy-specific nonovert DIC score, (2) to determine the diagnostic performance of this score in detecting women at risk for obstetrical hemorrhage requiring blood product transfusion, and (3) to compare it to the existing ISTH nonovert DIC score.

STUDY DESIGN

This retrospective study has longitudinal and cross-sectional components and includes three steps: (1) characterization of the longitudinal changes in the components of modified ISTH nonovert DIC scores, including these parameters - fibrinogen, antithrombin III, protein C, prothrombin time (PT), platelets, thrombin-antithrombin (TAT) complex, and D-dimer - during gestation in a group of normal pregnancies (n = 50); (2) development of a pregnancy-specific nonovert DIC score in a cross-sectional design of high-risk (n = 152) and control (n = 50) pregnancies, based on the predictive performance of each analyte for the detection of women at risk for obstetrical hemorrhage requiring blood product transfusion and a logistic regression model; and (3) comparison between the diagnostic performance of the pregnancy-specific nonovert DIC score and the modified ISTH nonovert DIC score to detect, upon admission, women who are at increased risk for subsequent development of obstetrical hemorrhage requiring blood product transfusion.

RESULTS

(1) The study cohort included 202 patients, of which 21 (10%) had obstetrical hemorrhage that required blood product transfusion and were considered to have nonovert DIC; (2) using the nonpregnant ISTH nonovert DIC score, 92% of the patients had a D-dimer concentration above the 0.5 mg/L threshold, and only 2% were identified to have a low fibrinogen concentration (<100 mg/dL); thus, this scoring system was unable to identify any of the patients with nonovert DIC based on the suggested cutoff of a score of ≥5; (3) the parameters included in the pregnancy-specific nonovert DIC score were selected based on their contribution to the performance of the model for the prediction of women at risk for obstetrical hemorrhage requiring blood product transfusion; as a result, we excluded the PT difference parameter from the score and the TAT complex concentration was added; and (4) a pregnancy-specific nonovert DIC score of ≥3 had a sensitivity of 71.4% and a specificity of 77.9% to identify patients at risk for obstetrical hemorrhage requiring blood product transfusion.

CONCLUSION

We propose (1) a pregnancy-specific nonovert DIC score adjusted for the physiologic changes in the hemostatic system during gestation; and (2) that the pregnancy-specific nonovert DIC score can be a useful tool for the identification of patients at risk for obstetrical hemorrhage requiring blood product transfusion.

Viscoelastic Hemostatic Assays for Postpartum Hemorrhage

This article discusses the importance and effectiveness of viscoelastic hemostatic assays (VHAs) in assessing hemostatic competence and guiding blood component therapy (BCT) in patients with postpartum hemorrhage (PPH). In recent years, VHAs such as thromboelastography and rotational thromboelastometry have increasingly been used to guide BCT, hemostatic adjunctive therapy and prohemostatic agents in PPH. The three pillars of identifying hemostatic competence include clinical observation, common coagulation tests, and VHAs. VHAs are advantageous because they assess the cumulative contribution of all components of the blood throughout the entire formation of a clot, have fast turnaround times, and are point-of-care tests that can be followed serially. Despite these advantages, VHAs are underused due to poor understanding of correct technique and result interpretation, a paucity of widespread standardization, and a lack of large clinical trials. These VHAs can also be used in cases of uterine atony, preeclampsia, acute fatty liver of pregnancy, amniotic fluid embolism, placental abruption, genital tract trauma, surgical trauma, and inherited and prepartum acquired coagulopathies. There exists an immediate need for a point-of-care test that can equip obstetricians with rapid results on developing coagulopathic states. The use of VHAs in predicting and treating PPH, although in an incipient state, can fulfill this need.

Effects of rotational thromboelastometry-guided transfusion management in patients undergoing surgical intervention for postpartum hemorrhage: An observational study

BACKGROUND

Postpartum hemorrhage (PPH) can be associated with coagulopathy, which may be difficult to rapidly assess and may exacerbate blood loss. Rotational thromboelastometry (ROTEM) at the point of care can guide clinician choice of blood products and has been shown in some settings to reduce transfusions and improve outcomes. This hospital-based observational study aims to measure effects of a ROTEM-guided transfusion protocol on transfusion practice and clinical outcomes in patients with PPH managed in the operating theater.

STUDY DESIGN AND METHODS

We compared a retrospective cohort of 450 consecutive patients with PPH treated in the operating theater before the introduction of a ROTEM-guided transfusion algorithm in June 2016, with 450 patients treated after its introduction. Multivariate regression was used to evaluate the effect of ROTEM introduction on the primary outcome, patients requiring a packed red blood cell (PRBC) transfusion and adjusting for demographic and obstetric confounders. Secondary outcomes included other blood product transfusions, hysterectomy, and intensive care unit admission.

RESULTS

A total of 90 (20%) of patients treated prior to ROTEM introduction received a PRBC transfusion, compared with 102 (22.7%) of those treated after ROTEM introduction (95% confidence interval [CI] 1.0-2.0, p = .04). There was no difference in PRBC transfusion in patients undergoing caesarean section (95% CI 0.5-1.8, p = .99). There was a trend toward increased use of cryoprecipitate and reduced use of platelets and fresh frozen plasma after ROTEM introduction.

CONCLUSION

In our institution, the introduction of ROTEM-guided transfusion did not reduce PRBC transfusion in patients with PPH treated in the operating theater.

Viscoelastic testing in benign hematologic disorders: Clinical perspectives and future implications of point-of-care testing to assess hemostatic competence

Viscoelastic tests (VETs) have been used routinely for liver transplantation, cardiac surgery, and trauma, but only recently have found clinical utility in benign hematologic disorders. Therefore, guidelines for diagnosis and treatment of these disorders based on viscoelastic variables have been adapted from the existing transplant, cardiothoracic surgery, and trauma resuscitation literature. As a result, diagnostic and therapeutic strategies for benign hematologic disorders utilizing VETs are not uniform. Accordingly, even though there has been a recent increase in the utilization of VET for the diagnosis and treatment of such disorders, the literature is still in its early stages. Analysis of point-of-care viscoelastic tracings from benign hematologic disorders has the potential to allow prompt recognition of disease and to guide patient-specific intervention. Here we present a review describing the application of VETs to benign hematologic disorders.

Effective tranexamic acid concentration for 95% inhibition of tissue-type plasminogen activator-induced hyperfibrinolysis in full-term pregnant women: a prospective interventional study

Postpartum haemorrhage is the leading cause of maternal mortality and morbidity worldwide. Tranexamic acid (TXA) has been shown to reduce blood loss and blood product transfusion requirements. Despite clinical evidence, further studies are needed to better define the pharmacokinetic and pharmacodynamic characteristics of TXA in pregnant women. The objective of our prospective observational ex-vivo study was to define the effective TXA concentration required to inhibit 95% (EC95) of tissue-type plasminogen activator (t-PA)-induced fibrinolysis in full-term pregnant women. Hyperfibrinolysis was induced by adding supraphysiologic concentration of t-PA to blood samples obtained from 30 full-term pregnant women and 10 healthy nonpregnant female volunteers. Increasing TXA concentrations (0--40 μg/ml) were then spiked into the blood samples and inhibition of fibrinolysis was assessed using the lysis index at 30 min of the ROTEM measured on EXTEM and NATEM tests. Effective TXA concentrations required to achieve EC95 were extrapolated using nonlinear regression. EC95 were compared between groups using an extra sum-of-squares F test. EC95 in pregnant women was 14.7 μg/ml (95% CI 12.4--17.5 μg/ml) on EXTEM and 11.2 μg/ml (95% CI 8.3--15.1 μg/ml) on NATEM tests. These values were significantly higher than those obtained in volunteers: 8.7 μg/ml (95% CI 5.5--13.9 μg/ml) and 6.8 μg/ml (95% CI 5.3--8.8 μg/ml), respectively (both P < 0.001). Our results suggest a higher fibrinolytic potential in pregnant women compared with nonpregnant women.

The impact of crystalloid versus colloid on coagulation as measured by thromboelastometry in term parturients: an in vitro study

OBJECTIVE

A pilot study to examine the impact of crystalloid versus albumin hemodilution in vitro on coagulation using thromboelastometry in pregnant patients.

METHODS

This prospective, observational pilot study included seventy-six pregnant patients at term (≥37 weeks) without history of bleeding or clotting disorder or on anticoagulation. Blood was collected and diluted with either Plasma-Lyte or albumin at the following levels: 0%, 20%, 25%, 30%, 35%, 40%, 45%, 55%, 60%, 65%, 70%, 75%, 80%. Thromboelastometry was performed to assess for coagulation changes.

RESULTS

There was a small, statistically significant difference in the FIBTEM A5 between the Plasma-Lyte and albumin samples. However, the predicted probability of coagulopathy, using FIBTEM A5 less than 12 mm, was not different between the groups at any dilution. There was no difference in EXTEM clotting time at low-moderate levels of hemodilution. At dilutions above 40%, the albumin group had a significantly greater prolongation in clotting time compared to the Plasma-Lyte group.

CONCLUSION

When albumin is used at low-moderate levels of hemodilution in vitro in parturients there is no additional risk of coagulopathy compared to hemodilution with crystalloid. Given that colloids are frequently used to restore intravascular volume during massive hemorrhage, these results support that during early stages of hemorrhage, albumin may not contribute to additional coagulopathy beyond that of hemodilution, although further in vivo studies are needed.

Severe thrombocytopenia in pregnancy: a retrospective study

: Thrombocytopenia is defined as a platelet count less than 150 000/μl and it is the most common hematologic disease after anemia in pregnancy. This study aims to investigate pregnant women with severe thrombocytopenia (platelet count <50 000/μl). In the relevant literature, few studies have addressed severe thrombocytopenia in pregnancy. This is a retrospective study based on the data from a reference center in Ankara, Turkey between January 2016 and December 2017. The study group consisted of 51 pregnant women who had two platelet counts lower than 50 000/μl. Descriptive statistical methods were utilized to analyze the results. The study analyzed the causes of severe thrombocytopenia, maternal and fetal-neonatal outcomes, and the management of the patients. The common causes of severe thrombocytopenia were hypertensive disorders (66.7%), immune thrombocytopenia (13.7%), massive obstetric hemorrhage (7.8%), and disseminated intravascular coagulation (5.9%). The preterm delivery occurred in 58.8% of the patients, and 46 live-births (two twins), six stillbirths, and one pregnancy termination emerged. Postpartum hemorrhage occurred in four (0.08%) patients, and blood transfusion was performed in 15 (29.4%) patients. The platelet transfusion was required to increase the platelet count of 30 (58.8%) patients. The study showed that the incidence of causes in severe thrombocytopenia in pregnancy varied considerably from mild and moderate thrombocytopenia. Despite severe thrombocytopenia, maternal and neonatal bleeding complications were infrequent in the study group.

Reduction in massive postpartum haemorrhage and red blood cell transfusion during a national quality improvement project, Obstetric Bleeding Strategy for Wales, OBS Cymru: an observational study

Background

Postpartum haemorrhage (PPH) is a major cause of maternal morbidity and mortality and its incidence is increasing in many countries despite management guidelines. A national quality improvement programme called the Obstetric Bleeding Strategy for Wales (OBS Cymru) was introduced in all obstetric units in Wales. The aim was to reduce moderate PPH (1000 mL) progressing to massive PPH (> 2500 mL) and the need for red cell transfusion.

Methods

A PPH care bundle was introduced into all 12 obstetric units in Wales included all women giving birth in 2017 and 2018 (n = 61,094). The care bundle prompted: universal risk assessment, quantitative measurement of blood loss after all deliveries (as opposed to visual estimation), structured escalation to senior clinicians and point-of-care viscoelastometric-guided early fibrinogen replacement. Data were submitted by each obstetric unit to a national database. Outcome measures were incidence of massive PPH (> 2500 mL) and red cell transfusion. Analysis was performed using linear regression of the all Wales monthly data.

Results

Uptake of the intervention was good: quantitative blood loss measurement and risk assessment increased to 98.1 and 64.5% of all PPH > 1000 mL, whilst ROTEM use for PPH > 1500 mL increased to 68.2%. Massive PPH decreased by 1.10 (95% CI 0.28 to 1.92) per 1000 maternities per year (P = 0.011). Fewer women progressed from moderate to massive PPH in the last 6 months, 74/1490 (5.0%), than in the first 6 months, 97/1386 (7.0%), (P = 0.021). Units of red cells transfused decreased by 7.4 (95% CI 1.6 to 13.2) per 1000 maternities per year (P = 0.015). Red cells were transfused to 350/15204 (2.3%) and 268/15150 (1.8%) (P = 0.001) in the first and last 6 months, respectively. There was no increase in the number of women with lowest haemoglobin below 80 g/L during this time period. Infusions of fresh frozen plasma fell and there was no increase in the number of women with haemostatic impairment.

Conclusions

The OBS Cymru care bundle was feasible to implement and associated with progressive, clinically significant improvements in outcomes for PPH across Wales. It is applicable across obstetric units of widely varying size, complexity and staff mixes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03853-y.

Early and systematic administration of fibrinogen concentrate in postpartum haemorrhage following vaginal delivery: the FIDEL randomised controlled trial

OBJECTIVE

To assess the benefits and safety of early human fibrinogen concentrate in postpartum haemorrhage (PPH) management.

DESIGN

Multicentre, double-blind, randomised placebo-controlled trial.

SETTING

30 French hospitals.

POPULATION

Patients with persistent PPH after vaginal delivery requiring a switch from oxytocin to prostaglandins.

METHODS

Within 30 minutes after introduction of prostaglandins, patients received either 3 g fibrinogen concentrate or placebo.

MAIN OUTCOME MEASURES

Failure as composite primary efficacy endpoint: at least 4 g/dl of haemoglobin decrease and/or transfusion of at least two units of packed red blood cells within 48 hours following investigational medicinal product administration. Secondary endpoints: PPH evolution, need for haemostatic procedures and maternal morbidity-mortality within 6 ± 2 weeks after delivery.

RESULTS

437 patients were included: 224 received FC and 213 placebo. At inclusion, blood loss (877 ± 346 ml) and plasma fibrinogen (4.1 ± 0.9 g/l) were similar in both groups (mean ± SD). Failure rates were 40.0% and 42.4% in the fibrinogen and placebo groups, respectively (odds ratio [OR] = 0.99) after adjustment for centre and baseline plasma fibrinogen; (95% CI 0.66-1.47; P = 0.96). No significant differences in secondary efficacy outcomes were observed. The mean plasma FG was unchanged in the Fibrinogen group and decreased by 0.56 g/l in the placebo group. No thromboembolic or other relevant adverse effects were reported in the Fibrinogen group versus two in the placebo group.

CONCLUSIONS

As previous placebo-controlled studies findings, early and systematic administration of 3 g fibrinogen concentrate did not reduce blood loss, transfusion needs or postpartum anaemia, but did prevent plasma fibrinogen decrease without any subsequent thromboembolic events.

TWEETABLE ABSTRACT

Early systematic blind 3 g fibrinogen infusion in PPH did not reduce anaemia or transfusion rate, reduced hypofibrinogenaemia and was safe.

When and how should I transfuse during obstetric hemorrhage?

The incidence of maternal hemorrhage and blood transfusion has increased over time. Causes of massive hemorrhage, defined as a transfusion > 10 units of erythrocytes, include abnormal placental insertion, preeclampsia, and placental abruption. Although ratio-based transfusion has been described for managing massive hemorrhage, a goal-directed approach using laboratory or point-of-care data may lead to better outcomes. Autotransfusion, which involves the collection, washing, and filtration of maternal shed blood, avoids many of the complications associated with allogeneic blood transfusion. In this review, we provide an overview of transfusion practices related to the management of obstetric hemorrhage.

Can measuring blood loss at delivery reduce hemorrhage-related morbidity?

Quantitation of blood loss after vaginal and cesarean delivery has been advocated for the timely detection of postpartum hemorrhage and activation of protocols for resuscitation. Morbidity and mortality from postpartum hemorrhage is considered to be largely preventable and is attributed to delayed recognition with under-resuscitation or inappropriate resuscitation. Optimizing detection of postpartum hemorrhage through refining how blood loss is measured is therefore clinically relevant. In this review on quantitative blood loss for postpartum hemorrhage, recent advances in the methods used to quantitate blood loss will be reviewed, with a comparison of utility and precision for blood loss measurement after vaginal and cesarean delivery. Considerations for the implementation of a quantitative blood loss system on the labor and delivery unit, including its benefits and challenges, will be discussed. The existing evidence for impact of blood loss quantitation in obstetrics on hemorrhage-related morbidity will be delineated, along with knowledge gaps and future research priorities.

Point-of-care blood clotting test and its correlation with fibrinogen level: Potential in goal-directed transfusion in postpartum hemorrhage

OBJECTIVE

To study the correlation of conventional point-of-care clotting test (POCCT) of whole blood with laboratory fibrinogen levels in women with primary major postpartum hemorrhage (PPH) to generate evidence regarding its potential in rationalizing transfusion of blood components for supplementing fibrinogen.

METHODS

A total of 68 samples were studied: 40 from women with primary major PPH, 20 from women without PPH, and eight samples of Fresh Frozen Plasma (FFP). POCCT was performed in the PPH and non-PPH groups and at the same time, sample for laboratory fibrinogen was sent. Values were correlated using Pearson's correlation coefficient (r). Depending upon the laboratory fibrinogen values, POCCT in the PPH group was divided into three subgroups of less than 7, 7-11, and more than >11 min as subgroups 1, 2, and 3, respectively.

RESULTS

Women in the PPH group (n = 40) had a mean fibrinogen level of 346.15 ± 143.37 mg% with a significant negative correlation with POCCT (r = -0.69, P < 0.001). Mean fibrinogen levels of non-PPH group and FFP samples were 602.1 ± 169.72 and 286.75 ± 103.42 mg%, respectively. PPH subgroups 1, 2, and 3 had mean fibrinogen of 452.2 ± 141.8, 332.58 ± 138.51, and 158.71 ± 145 mg%, respectively. These values may potentially guide FFP transfusions.

CONCLUSION

POCCT is easy, costs nothing and has a potential role in rationalizing FFP transfusion in low- and middle-income countries.

South African Society of Anaesthesiologists Perioperative Patient Blood Management Guidelines 2020

Anaesthesiologists regularly request and administer blood components to their patients, a potentially life-saving intervention. All anaesthesiologists must be familiar with the indications and appropriate use of blood and blood components and their alternatives, but close liaison with haematologists and their local haematology blood sciences laboratory is encouraged. In the last decade, there have been considerable changes in approaches to optimal use of blood components, together with the use of alternative products, with a need to update previous guidelines and adapt them for anaesthesiologists working throughout the hospital system.

Functional Testing for Tranexamic Acid Duration of Action Using Modified Viscoelastometry

Introduction

Tranexamic acid (TXA) is the standard medication to prevent or treat hyperfibrinolysis. However, prolonged inhibition of lysis (so-called "fibrinolytic shutdown") correlates with increased mortality. A new viscoelastometric test enables bedside quantification of the antifibrinolytic activity of TXA using tissue plasminogen activator (TPA).

Materials and Methods

Twenty-five cardiac surgery patients were included in this prospective observational study. In vivo, the viscoelastometric TPA test was used to determine lysis time (LT) and maximum lysis (ML) over 96 h after TXA bolus. Additionally, plasma concentrations of TXA and plasminogen activator inhibitor 1 (PAI-1) were measured. Moreover, dose effect curves from the blood of healthy volunteers were performed in vitro. Data are presented as median (25-75th percentile).

Results

In vivo TXA plasma concentration correlated with LT (r = 0.55; p < 0.0001) and ML (r = 0.62; p < 0.0001) at all time points. Lysis was inhibited up to 96 h (LT_TPA-test: baseline: 398 s [229-421 s] vs. at 96 h: 886 s [626-2,175 s]; p = 0.0013). After 24 h, some patients (n = 8) had normalized lysis, but others (n = 17) had strong lysis inhibition (ML <30%; p < 0.001). The high- and low-lysis groups differed regarding kidney function (cystatin C: 1.64 [1.42-2.02] vs. 1.28 [1.01-1.52] mg/L; p = 0.002) in a post hoc analysis. Of note, TXA plasma concentration after 24 h was significantly higher in patients with impaired renal function (9.70 [2.89-13.45] vs.1.41 [1.30-2.34] µg/mL; p < 0.0001). In vitro, TXA concentrations of 10 µg/mL effectively inhibited fibrinolysis in all blood samples.

Conclusions

Determination of antifibrinolytic activity using the TPA test is feasible, and individual fibrinolytic capacity, e.g., in critically ill patients, can potentially be measured. This is of interest since TXA-induced lysis inhibition varies depending on kidney function.

The role of ultrasound in prediction of intra-operative blood loss in cases of placenta accreta spectrum disorders

PURPOSE

To assess the value of various grey-scale ultrasound, 2D color Doppler, and 3D power Doppler sonographic markers in predicting major intraoperative blood loss during planned cesarean hysterectomy for cases diagnosed with placenta accreta spectrum (PAS) disorders.

METHODS

50 women diagnosed with PAS were scanned the day before planned delivery and hysterectomy for various sonographic markers indicative of placental invasion. These women were then later divided according to blood loss in two groups: group A (minor hemorrhage, < 2500 ml), and group B (major hemorrhage, > 2500 ml), and the data were analyzed.

RESULTS

The odds ratio (OR) for major hemorrhage was as follows for the following sonographic markers: 'number of lacunae > 4' OR 3.8 95% CI (1.0-13.8) (p = 0.047); 'subplacental hypervascularity' OR 10.8 95% CI (1.2-98.0) (p = 0.035); 'tortuous vascularity with 'chaotic branching' OR 10.8 95%CI (1.2-98.0) (p = 0.035); 'numerous coherent vessels involving the serosa-bladder interface OR 14.6 95% CI (2.7-80.5) (p = 0.002); and 'presence of bridging vessels OR 2.9 95% CI (1.4-6.9) (p = 0.005). Only the presence of numerous coherent vessels involving the bladder-serosal interface (p = 0.002) was proven to be independent predictor of major hemorrhage during hysterectomy.

CONCLUSION

The use of 2D color Doppler and 3D power Doppler can help predict massive hemorrhage in cases of PAS disorders.

The role of viscoelastic testing in the management of the parturient

Viscoelastic testing is the measurement of how the viscoelastic properties of blood change as blood clots. In pregnancy, unique changes in clotting function occur overall to make the pregnant woman hypercoagulable. Viscoelastic testing may be able to play a role in guiding placement of epidural and spinal anesthetics by demonstrating enhanced coagulation function, even when there are individual parts of the coagulation system that are abnormal, for example, thrombocytopenia. These tools may also play a role in addressing the management of maternal hemorrhage, which in the United States is on the rise. This review discusses the opportunity to use viscoelastic testing in the parturient.

The effects of hemodilution on coagulation in term parturients: an in vitro study utilizing rotational thromboelastometry

Objective: To examine the impact of hemodilution on components of blood coagulation using rotational thromboelastometry (ROTEM^®) in term parturientsMethods: This is a prospective, observational pilot study including 35 healthy, parturients at term (≥37 weeks) without history of bleeding or clotting disorder or on medication affecting coagulation. Venous blood samples were collected and divided into specimen tubes to generate varying degrees of hemodilution with Plasma-Lyte (0%, 20%, 25%, 30%, 35%, 40%, 45%, 55%, 60%, 65%, 70%, 75%, 80%). ROTEM^® was performed to assess for coagulation changes.Results: EXTEM (extrinsically activated assay) clotting time (CT) became prolonged at 65% hemodilution and above, and the median CT was in the coagulopathic range (>80 s) at a dilution of 80%. FIBTEM (extrinsically activated assay with platelet inhibitor) amplitude at 5 min (A5) began to diminish at 35% hemodilution, with the median A5 in the coagulopathic range (<12 mm) at 55% hemodilution. The area under the curve (AUC) for EXTEM and FIBTEM consistently declined as hemodilution increased. Greater decreases in FIBTEM AUC were seen compared to EXTEM AUC, with the ratio of FIBTEM:EXTEM AUC at each dilution demonstrating a statistically significant difference from baseline.Conclusion: All thromboelastometry values demonstrated a hypocoagulable trend as hemodilution increased. However, the samples analyzed by the FIBTEM assay trended toward a coagulopathy at a lower degree of hemodilution compared to the EXTEM assay. As FIBTEM tests analyze the role of fibrinogen in hemostasis and EXTEM tests analyze the role of platelets, our findings suggest that platelets may be able to withstand higher degrees of hemodilution before impairing hemostasis compared to fibrinogen. These findings support the growing body of literature that in early stages of severe obstetric hemorrhage, the prioritization of fibrinogen replacement may be critical in preventing further coagulopathy.

How do I manage severe postpartum hemorrhage?

In the United States, postpartum hemorrhage (PPH) accounts for 4.6% of all maternal deaths and is responsible for major peripartum medical and surgical morbidity. Therefore, a national health priority is to ensure that women who experience severe PPH receive timely, appropriate, and effective treatment. In this article, we describe our system-wide approach for the planning and delivery of women with suspected placenta accreta spectrum disorder, a condition associated with life-threatening blood loss at the time of delivery. We also highlight current evidence related to transfusion decision making and hemostatic monitoring during active postpartum bleeding. Specifically, we describe how we activate and use the massive transfusion protocol to obtain sufficient volumes and types of blood products. We also describe how we use viscoelastic monitoring (thromboelastography) and standard laboratory tests to assess the maternal coagulation profile. Finally, we review the findings of recent studies examining the potential efficacy of tranexamic acid and fibrinogen concentrate as adjuncts for PPH prevention and treatment. We describe how we have incorporated these drugs into PPH treatment protocols at our institution.

Designing and implementing an all Wales postpartum haemorrhage quality improvement project: OBS Cymru (the Obstetric Bleeding Strategy for Wales)

BACKGROUND

Postpartum haemorrhage (PPH) contributes to substantial maternal morbidity. Research into PPH has led to improvements in care which have been incorporated into the Obstetric Bleeding Strategy for Wales.

INTERVENTION

A national quality improvement team supported local teams in implementing multiple interventions including risk assessment, objective measurement of blood loss, multiprofessional assessment (at the bedside at 1000 mL blood loss) and point-of-care (POC) testing of coagulation to guide blood product resuscitation during PPH. The project was rolled out to all 12 obstetric units in 2017. The interventions were reinforced by an All Wales Guideline, PPH proforma and standardised training. A national database, biannual audits, and patient and staff surveys reported process and outcome measures.

RESULTS

Process measures: during 2017, there was an increase in the percentage of maternities with documented risk assessment (0%-76%), objective measurement of blood loss (52%-88%) and POC testing for coagulation for PPH ≥1500 mL (38%-59%). Maternity staff survey indicated that 94% were aware of the project and 87% stated that it had changed their unit's management of PPH. Interim outcome measures: the incidence (95% CI) of PPH ≥2500 mL per 1000 maternities in 2017 was 6.03 (5.23-6.95). The annual number of women receiving any red blood cell transfusion, level 3 intensive care admission and hysterectomy for PPH was 19.7 (18.2 to 21.3), 0.702 (0.464 to 1.06) and 0.255 (0.129 to 0.504) per 1000 maternities, respectively.

CONCLUSIONS

A high level of project awareness across Welsh maternity units has been achieved. Measurement of blood loss was reported to be the most important early change in practice, while PPH documentation and POC testing continue to be embedded. Combining qualitative and quantitative measures to inform implementation has improved project delivery and allowed teams to adapt to local contexts.

Observational Safety Study of Clottafact® Fibrinogen Concentrate: Real-World Data in Mexico

BACKGROUND AND OBJECTIVE

The use of fibrinogen concentrate to treat or prevent major bleeding with regard to potential adverse reactions has not been free of controversy. Our objective was to perform a post-authorization safety study to describe the use of Clottafact^® (LFB Biomedicaments) fibrinogen concentrate in real-life medical practice in Mexico.

METHODS

This was a prospective, observational study that collected and evaluated information between January 2017 and June 2019 related to suspected serious adverse reactions (SUSARs) during and after Clottafact^® infusion.

RESULTS

Information from 40 subjects was analyzed; 43% were women (n = 17), mean age was 39.05 ± 26.8 years (range 0-91 years). The medical specialties included in this analysis were cardiac surgery - 52.5% of the cases, gynecology/obstetrics - 17.5%, general surgery and orthopedics - 12.5% each, and hematology and neurosurgery - 2.5%, respectively. Mean plasma fibrinogen levels before and after Clottafact^® infusion were 2.58 g/L and 4.02 g/L; p = 0.001, respectively. The mean Clottafact^® dose was 2.20 ± 0.77 g. One patient presented SUSARs (dry mouth and dysgeusia) with drug administration, which ceased after treatment discontinuation.

CONCLUSIONS

In this real-life post-marketing study, the safety profile of Clottafact^® was very similar to previous reports. Thus, Clottafact^® shows a favorable safety profile in clinical practice.

Effect of tranexamic acid on symptomatic venous thromboembolism in patients undergoing primary total knee arthroplasty

INTRODUCTION

This study aimed to investigate the effect of tranexamic acid (TXA) with sequential routine anticoagulation on postoperative symptomatic venous thromboembolism (VTE) in patients undergoing primary total knee arthroplasty (TKA).

MATERIAL AND METHODS

This was a prospective study with randomized trials. From January 2013 to May 2015, 1880 patients undergoing primary TKA were enrolled in this study. Seven hundred and twenty patients who received TXA injection were included in the TXA group while 1160 patients who received placebo injection were included in the control group. Patients in the TXA group were treated with intravenous TXA or topical intravenous TXA, and all received sequential routine anticoagulation 12 h after the operation. We extracted data of patients' sex, age, primary diagnoses, and comorbidities that could potentially affect the prevalence rate of VTE. To discuss the risk factors of symbolic VTE, comparisons were made within the TXA group between patients with symbolic VTE and non-symbolic VTE. Logistic regression analysis was performed to analyze the concurrent effects of various factors on the prevalence rate of postoperative VTE.

RESULTS

Thigh perimeter was not closely associated with TXA injection. Within the TXA group, 24 (3.3%) patients had perioperative symptomatic VTE, 16 (2.2%) deep vein thrombosis (DVT) and 8 (1.1%) pulmonary embolism. High body mass index (BMI), low fibrinogen (Fbg) and simultaneous bilateral TKA were significant risk factors in both univariate analysis and multivariate analysis.

CONCLUSIONS

Increased BMI, low Fbg, and simultaneous bilateral TKA could act as risk factors for postoperative symptomatic VTE treated with TXA.

New method for determining fibrinogen and FDP threshold criteria by artificial intelligence in cases of massive hemorrhage during delivery

AIM

To investigate the feasibility of a novel method using artificial intelligence (AI), in which the fibrinogen criterion was determined by the quantitative relation between the distributions of fibrin/fibrinogen degradation products (FDPs) and fibrinogen.

METHODS

A dataset of 154 deliveries comprising more than 2000 g of blood lost due to hemorrhage, excluding disseminated intravascular coagulation (DIC), among patients from eight national perinatal centers in Japan from 2011 to 2015 were obtained. The fibrinogen threshold criterion was identified by using the function that best fit the distributions of FDP as determined by AI. FDP production was described by differential equations using a dataset containing fibrinogen levels less than the fibrinogen criterion and solved numerically.

RESULTS

A fibrinogen level of 237 mg/dL as the threshold criterion was obtained. The FDP threshold criteria were 2.0 and 8.5 mg/dL for no coagulopathy and a failed coagulation system, respectively.

CONCLUSION

The fibrinogen threshold criterion for patients with massive hemorrhage excluding DIC at delivery were obtained by selecting the functions that best fit the distributions of FDP data by using AI.

Coagulation parameters during the course of severe postpartum hemorrhage: a nationwide retrospective cohort study

We describe the pattern of change in coagulation parameters during the course of severe postpartum hemorrhage in a retrospective cohort study among 1312 women experiencing severe postpartum hemorrhage necessitating blood transfusion. Levels of hemoglobin, hematocrit, platelet count, fibrinogen, activated partial thromboplastin time (aPTT) and prothrombin time (PT) per categorized volume of blood loss during severe postpartum hemorrhage were described and compared between women with and without the composite adverse outcome. Need for surgical intervention, severe acute maternal morbidity, and maternal mortality were jointly considered the composite adverse outcome. Of the 1312 women, 463 (35%) developed the composite adverse outcome. The incidence of a fibrinogen level <2 g/L was 26% (342 per 1312). Low fibrinogen and prolonged aPTT during the first 2 L of hemorrhage were associated with a subsequent composite adverse outcome; median fibrinogen and aPTT among women with and without the composite end point after 1.5 to 2 L of hemorrhage were 1.5 g/L (interquartile range [IQR], 1.0-1.9) vs 2.7 g/L (IQR, 1.9-3.4) and 39 s (IQR, 30-47) vs 32 s (IQR, 28-36), respectively. PT and platelet count as assessed during the first 2 L of hemorrhage were not associated with morbidity or mortality. Our results suggest that detection of low levels of fibrinogen and elevated aPTT levels during early postpartum hemorrhage can contribute to the identification of women that may benefit from targeted hemostatic treatment. Essential in this identification process is the moment of reaching a level of fibrinogen of <2 g/L during the course of postpartum hemorrhage.

Functional fibrinogen (FLEV-TEG) versus the Clauss method in an obstetric population: a comparative study

BACKGROUND

Hemostasis is the dynamic equilibrium between coagulation and fibrinolysis. During pregnancy, the balance shifts toward a hypercoagulative state; however placental abruption and abnormal placentations may lead to rapidly evolving coagulopathy characterized by the increased activation of procoagulant pathways. These processes can result in hypofibrinogenemia, with fibrinogen levels dropping to 2 g/L or less and an associated increased risk of post-partum hemorrhage. The aim of the present study was to evaluate the concordance between two methods of functional fibrinogen measurement: the Thromboelastography (TEG) method (also known as FLEV) vs. the Clauss method. Three patient groups were considered: healthy volunteers; non-pathological pregnant patients; and pregnant patients who went on to develop postpartum hemorrhage.

METHODS

A prospective observational study. Inclusion criteria were: healthy volunteer women of childbearing age, non-pathological pregnant women at term, and pregnant hemorrhagic patients subjected to elective or urgent caesarean section (CS), with blood loss exceeding 1000 mL. Exclusion criteria were age < 18 years, a history of coagulopathy, and treatment with contraceptives, anticoagulants, or antiplatelet agents.

RESULTS

Bland-Altman plots showed a significant overestimation with the FLEV method in all three patient groups: bias was - 133.36 mg/dL for healthy volunteers (95% IC: - 257.84; - 8.88. Critical difference: 124.48); - 56.30 mg/dL for healthy pregnant patients (95% IC: - 225.53; 112.93. Critical difference: 169.23); and - 159.05 mg/dL for hemorrhagic pregnant patients (95% IC: - 333.24; 15.148. Critical difference: 174.19). Regression analyses detected a linear correlation between FLEV and Clauss for healthy volunteers, healthy pregnant patients, and hemorrhagic pregnant patients (R² 0.27, p value = 0.002; R² 0.31, p value = 0.001; R² 0.35, p value = 0.001, respectively). ANOVA revealed a statistically significant difference in fibrinogen concentration between all three patients groups when assayed using the Clauss method (p value < 0.001 for all the comparisons), but no statistically significant difference between the two patients groups of pregnant women when using the FLEV method.

CONCLUSIONS

The FLEV method does not provide a valid alternative to the Clauss method due to the problem of fibrinogen overestimation, and for this reason it should not be recommended for the evaluation of patients with an increased risk of hypofibrinogenemia.

Treatment of Obstetric Hemorrhage with Fibrinogen Concentrate

Background

Postpartum hemorrhage (PPH) is related to several factors but is frequently associated with coagulopathy with maternal mortality. Fibrinogen is a very important agent for bleeding. When its concentration is decreased, severe surgical blood loss may occur. Here, we investigate the association of postpartum bleeding characteristics with evolution of PPH in patients who were taking fibrinogen concentrate (FC).

Material/Methods

PPH patients’ demographic parameters, outcome variables, and laboratory findings before and at ICU were recorded between January 2015 and July 2017. The duration of ICU stay and plasmapheresis, renal replacement therapy, maternal-fetal deaths, RBC, FFP, and PC replacement were calculated.

Results

Group I: Fibrinogen levels were ≤150 mg/dl (n: 31), Group II: Fibrinogen levels were >151 mg/dl (n: 18). In the peroperative period, there was no difference between the 2 groups in terms of RBC, FFP, or PC transfussion. In intraoperative and ICU admission period, patients in Group I had higher INR, APTT, and PT values than in the other group. FC replacement according to fibrinogen level was given, ranging from to 1 to 6 gr in Group I and 1–2 gr in Group II intraoperatively and at ICU 2–8 gr FC was given in both groups. In the intraoperative and ICU admission period, blood transfusion requirements of patients after fibrinogen replacement were evaluated and there was no statistically significant difference between groups. There were no differrences between groups in duration of intensive care unit stay, hospital stay, and mechanical ventilation.

Conclusions

Adequate FC therapy prevents unnecessary RBC, FFP, and PC replacement and prevents complications and volume overload.