Excessive fibrinolysis detected with thromboelastography in a case of amniotic fluid embolism: fibrinolysis may precede coagulopathy

A Case of Consumptive Coagulopathy Before Cardiopulmonary Failure in Amniotic Fluid Embolism and Review of Literature: A Perspective of the Latent Onset and Progression of Coagulopathy

Amniotic fluid embolism (AFE) induces cardiopulmonary insufficiency with consumptive coagulopathy. Previous studies reported that refractory coagulopathy has already advanced at the onset of maternal cardiovascular and/or respiratory symptoms. However, when the consumption of coagulation factors starts during the clinical course, AFE remains to be elucidated. We report an intrapartum AFE case of consumptive coagulopathy before dyspnea with hypotension developing during urgent cesarean delivery that was revealed by non-reassuring fetal heart rate tracing. The patient, a 42-year-old multiparous parturient, underwent induced labor after a premature rupture of membranes in week 39 of pregnancy. Coagulation screening was initially within the normal range. Fetal heart rate monitoring demonstrated bradycardia coincided with uterine tachysystole after three hours, which required urgent cesarean section with preoperative blood screening. The hemoglobin level was maintained at 129 g/L; however, the fibrinogen value reduced to 1.79 g/L with D-dimer elevation over 60 µg/mL. Ninety minutes later, she developed dyspnea with hypotension at suturing hysterotomy. At the end of surgery, her fibrinogen further decreased to below 0.3 g/L with prolonged prothrombin time. After vigorous intensive care, she was discharged without sequelae. Consumptive coagulopathy may initiate and progress before apparent cardiopulmonary symptoms in some AFE cases. Non-reassuring fetal heart rate tracing concomitant with abrupt uterine tachysystole and/or hypertonus may be an earlier time point for the detection and intervention of AFE-related coagulopathy.

Amniotic Fluid Embolism Coagulopathy Guided by the Point-of-Care Quantra QStat® Hemostasis System: A Case Report

Amniotic fluid embolism (AFE) is a rare pregnancy complication associated with high maternal mortality that occurs during labor or in the early postpartum period. The diagnosis of AFE is challenging because signs and symptoms are common to other obstetric complications. Early identification and management of profound coagulopathy associated with AFE is essential to improve patient survival. We present a case of a 31-year-old woman with placenta previa and clinical suspicion of AFE after cesarean section. Immediately after delivery, the parturient presented hypotension, hypoxia, coagulopathy, and severe postpartum hemorrhage. We hereby discuss the role of the most recently developed point-of-care viscoelastic testing device, the Quantra QStat® system (Stago Group Company; HemoSonics LLC, Durham, NC), for early detection of acute obstetric coagulopathy and guided hemostatic treatment.

Comparative analysis of hyperfibrinolysis with activated coagulation between amniotic fluid embolism and severe placental abruption

Amniotic fluid embolism (AFE) and placental abruption (PA) are typical obstetric diseases associated with disseminated intravascular coagulation (DIC). AFE is more likely to be complicated with enhanced fibrinolysis than PA. AFE may have an additional mechanism activating fibrinolytic cascade. We aimed to compare the coagulation/fibrinolysis factors among AFE, PA, and peripartum controls. We assessed AFE cases registered in the Japanese AFE Registry, and PA cases complicated with DIC (severe PA) and peripartum controls recruited at our hospital. The following factors in plasma were compared: prothrombin fragment 1 + 2 (PF1 + 2), plasmin α2-plasmin inhibitor complex (PIC), tissue factor (TF), tissue plasminogen activator (tPA), annexin A2 (AnnA2), total thrombin activatable fibrinolysis inhibitor (TAFI) including its activated form (TAFIa), and plasminogen activator inhibitor-type 1 (PAI-1). PF1 + 2 and PIC were markedly increased in both AFE (n = 27) and severe PA (n = 12) compared to controls (n = 23), without significant difference between those disease groups; however, PIC in AFE showed a tendency to elevate relative to PF1 + 2, compared with severe PA. AFE had significantly increased tPA and decreased total TAFI levels compared with severe PA and controls, which might be associated with further plasmin production in AFE and underlie its specific fibrinolytic activation pathway.

The Role of Thromboelastography during the Management of Postpartum Hemorrhage: Background, Evidence, and Practical Application

Postpartum hemorrhage (PPH) is a common cause of significant maternal morbidity and mortality that can be associated with coagulopathy, especially hypofibrinogenemia. There is interest in point-of-care viscoelastic hemostatic assays (POC-VHA) in PPH because prompt knowledge of coagulation status can aid diagnosis, identify cases of severe coagulopathy, and allow ongoing monitoring during rapid bleeding. The incidence of coagulopathy in most cases of PPH is low because of the procoagulant state of pregnancy, including raised fibrinogen levels of around 4 to 6 g/L. A Clauss fibrinogen of >2 g/L or POC-VHA equivalent has been found to be adequate for hemostasis during PPH. POC-VHA has been used successfully to diagnose hypofibrinogenemia (Clauss fibrinogen of ≤2 g/L) and guide fibrinogen treatment which has reduced bleed size and complications of massive transfusion. There are uncertainties about the use of POC-VHA to direct fresh frozen plasma and platelet administration during PPH. Several POC-VHA algorithms have been used successfully incorporated in the management of many thousands of PPHs and clinicians report that they are easy to use, interpret, and aid decision making. Due to the relative cost of POC-VHA and lack of definitive data on improving outcomes, these devices have not been universally adopted during PPH.

Pulmonary Embolism and Amniotic Fluid Embolism

Venous thromboembolism (VTE) as well as other embolic events including amniotic fluid embolism (AFE) remain a leading cause of maternal death in the United States and worldwide. The pregnant patient is at a higher risk of developing VTE including pulmonary embolism. In contrast, AFE is a rare, but catastrophic event that remains incompletely understood. Here the authors review the cause of VTE in pregnancy and look at contemporary and evidence-based practices for the evaluation, diagnosis, and management in pregnancy. Then the cause and diagnostic difficulty of AFE as well as what is known regarding the pathogenesis are reviewed.

Utilization of point-of-care ultrasound and rotational thromboelastometry (ROTEM) in the diagnosis and management of amniotic fluid embolism presenting as post-partum hemorrhage and cardiac arrest

Objectives

To describe the integration of point-of-care ultrasound (POCUS) and rotational thromboelastometry (ROTEM) in the diagnosis and management of cardiac arrest secondary to amniotic fluid embolism (AFE).

Case presentation

A 29-year-old female presented for induction of labor at 39 weeks. Labor was complicated by hemorrhage and subsequent sinus tachycardia pulseless electrical activity (PEA) arrest. Intra-arrest POCUS demonstrated right ventricular dilation and hypokinesis adding to a presumed hemorrhagic arrest etiology. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) was initiated at the bedside following the POCUS findings. ROTEM further clarified the etiology of hemorrhage as disseminated intravascular coagulation (DIC), and in combination with the POCUS findings led to a final diagnosis of amniotic fluid embolism with DIC. The patient was maintained on VA-ECMO without heparin in the setting of DIC. She had a complicated hospital course but was discharged home with her healthy child and no residual physical or neurologic deficits.

Conclusions

In the absence of more specific testing modalities the utilization of rapidly available POCUS in conjunction with ROTEM can impact clinical decision making of cardiovascular resuscitation in patients during labor and delivery by narrowing the differential between pulmonary embolism and AFE.

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.

Amniotic fluid embolism: lessons for rapid recognition and intervention

Amniotic fluid embolism is a rare, often fatal complication of labor and delivery. The classic presentation is the sudden onset of a triad of clinical manifestations: hypoxia, hypotension and coagulopathy. Understanding of the syndrome as an immunologically mediated, complicated and often catastrophic maternal response to fetal or placental antigens is coming into focus. New treatments such as extracorporeal membrane oxygenation (ECMO) and better use of old treatments such as transfusion offer hope, but the condition is often rapidly fatal, so saving the maternal and fetal lives depends on rapid recognition of the syndrome. This series of three cases illustrates the clinical features enabling the rapid recognition needed for successful treatment of amniotic fluid embolism syndrome.