Amniotic Fluid Embolism with Haemostasis Complications: Primary Fibrinogenolysis or Disseminated Intravascular Coagulation?

Consumptive Coagulopathy Involving Amniotic Fluid Embolism: The Importance of Earlier Assessments for Interventions in Critical Care

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Objectives:

Amniotic fluid embolism is a rare disease that induces fatal coagulopathy; however, due to its rarity, it has not yet been examined in detail. The strict diagnostic criteria by Clark for amniotic fluid embolism include severe coagulopathy complicated by cardiopulmonary insufficiency, whereas the Japanese criteria also include postpartum hemorrhage or Disseminated Intravascular Coagulation in clinical practice. Amniotic fluid embolism cases with preceding consumptive coagulopathy may exist and are potential clinical targets for earlier assessments and interventions among amniotic fluid embolism cases fulfilling the Japanese, but not Clark criteria. The present study was performed to compare coagulopathy in the earlier stage between the amniotic fluid embolism patients diagnosed by Clark criteria (Clark group, n = 6), those by the Japanese criteria (Non-Clark group, n = 10), and peripartum controls and identify optimal clinical markers for earlier assessments of amniotic fluid embolism-related consumptive coagulopathy.

Design:

Retrospective case-control study.

Setting:

A single university-based center. Our amniotic fluid embolism registry program has accumulated clinical information and blood samples since 2003.

Patients:

Amniotic fluid embolism patients in the Clark and Non-Clark groups between 2009 and 2017 and peripartum controls.

Interventions:

None.

Measurements and Main Results:

Clinical information was collected on hemoglobin levels, platelet counts, and coagulation- and fibrinolysis-related variables. Fibrinolytic parameters were also measured and compared among the three groups before blood transfusion. Fibrinogen levels in all patients in the Clark group and most in the Non-Clark group decreased earlier than hemoglobin levels, which was consistent with the high hemoglobin/fibrinogen ratio and, thus, is a promising clinical marker for the earlier assessment of amniotic fluid embolism-related consumptive coagulopathy.

Conclusions:

Earlier evaluations of consumptive coagulopathy and hyperfibrinolysis using the hemoglobin/fibrinogen ratio following preemptive treatment may reduce the occurrence or prevent the aggravation of severe coagulopathy in amniotic fluid embolism patients.

Amniotic fluid embolism-associated coagulopathy: a single-center observational study

INTRODUCTION

Amniotic fluid embolism (AFE) continues to be a rare, enigmatic condition with high maternal mortality. It is characterized by cardiovascular compromise, loss of consciousness or other neurologic symptoms, and coagulopathy. The latter is usually treated according to existing protocols for consumptive coagulopathy.

METHODS

Serial analyses of a panel of hemostaseological parameters were performed in three consecutive cases of AFE that occurred at our institution.

RESULTS

All mothers and neonates survived without major sequelae. Disproportionately low levels of fibrinogen and factor five, and exorbitantly elevated D-dimers were present in all cases, whereas markers of consumptive coagulopathy, platelets and antithrombin in particular, were only slightly reduced.

DISCUSSION

Our results support hyperfibrinolysis as contributing factor of AFE-associated coagulopathy. We, therefore, propose a treatment algorithm which includes early use of tranexamic acid and transfusion of red blood cells and fresh frozen plasma, adding fibrinogen if hemostasis is not readily achieved.

TRAnexamic acid in hemorrhagic CESarean section (TRACES) randomized placebo controlled dose-ranging pharmacobiological ancillary trial: study protocol for a randomized controlled trial

BACKGROUND

Evidence increases that a high or a standard dose of tranexamic acid (TA) reduces postpartum bleeding. The TRACES pharmacobiological substudy aims to establish a therapeutic strategy in hemorrhagic (H) Cesarean section (CS) with respect to the intensity of fibrinolysis by using innovative assays.

METHOD/DESIGN

The TRACES trial is a multicenter, randomized, double-blind, placebo-controlled, TA dose-ranging study that measures simultaneously plasmatic and uterine and urine TA concentrations and the plasmin peak inhibition tested by a simultaneous thrombin plasmin generation assay described by Van Geffen (novel hemostasis assay [NHA]). Patients undergoing H CS (>800 mL) will receive blindly TA 0.5 g or 1 g or placebo. A non-hemorrhagic (NH) group will be recruited to establish plasmin generation profile. Venous blood will be sampled before, at the end, and then at 30, 60, 120, and 360 min after injection. Uterine bleeding will be sampled after injection. Urine will be sampled 2 h and 6 h after injection. The number of patients entered into the study will be 114 H + 48 NH out of the 390 patients of the TRACES clinical trial.

DISCUSSION

To explore the two innovative assays, a preliminary pilot study was conducted. Blood samples were performed repeatedly in patients undergoing either a H (>800 mL) or NH (<800 mL) CS and in non-pregnant women (NP). H patients received TA (0-2 g). Dose-dependent TA plasmatic concentrations were determined by LC-MS/MS quantification. Plasmin generation and its inhibition were tested in vitro and in vivo using the simultaneous thrombin-plasmin generation assay (STPGA). The pilot study included 15 patients in the H group, ten patients in the NH group, and seven patients in the NP group. TA plasmatic concentration showed a dose-dependent variation. STPGA inter-assay variation coefficients were < 20% for all plasmin parameters. Inter-individual dispersion of plasmin generation capacity was higher in H and NH groups than in NP group. Profile evolution over time was different between groups. This preliminary technical validation study allows TRACES pharmacobiological trial to be conducted.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02797119. Registered on 13 June 2016.

Therapeutic and pharmaco-biological, dose-ranging multicentre trial to determine the optimal dose of TRAnexamic acid to reduce blood loss in haemorrhagic CESarean delivery (TRACES): study protocol for a randomised, double-blind, placebo-controlled trial

Background

Postpartum haemorrhage (PPH) is the leading cause of maternal death worldwide. Tranexamic acid (TA), an antifibrinolytic drug, reduces bleeding and transfusion need in major surgery and trauma. In ongoing PPH following vaginal delivery, a high dose of TA decreases PPH volume and duration, as well as maternal morbidity, while early fibrinolysis is inhibited. In a large international trial, a TA single dose reduced mortality due to bleeding but not the hysterectomy rate. TA therapeutic dosages vary from 2.5 to 100 mg/kg and seizures, visual disturbances and nausea are observed with the highest dosages. TA efficiency and optimal dosage in haemorrhagic caesarean section (CS) has not been yet determined. We hypothesise large variations in fibrinolytic activity during haemorrhagic caesarean section needing targeted TA doses for clinical and biological efficacy.

Methods/design

The current study proposal is a blinded, randomised controlled trial with the primary objective of determining superiority of either 1 g of TXA or 0.5 g of TXA, in comparison to placebo, in terms of 30% blood-loss reduction at 6 h after non-emergency haemorrhagic caesarean delivery (active PPH > 800 mL) and to correlate this clinical effect in a pharmacokinetics model with fibrinolysis inhibition measured by an innovative direct plasmin measurement regarding plasmatic TA concentration.

A sample size of 342 subjects (114 per group) was calculated, based on the expected difference of 30% reduction of blood loss between the placebo group and the low-dose group, out of which 144 patients will be included blindly in the pharmaco-biological substudy. A non-haemorrhagic reference group will include 48 patients in order to give a reference for peak plasmin level.

Discussion

TRACES trial is expected to give the first pharmacokinetics data to determinate the optimal dose of tranexamic acid to reduce blood loss and inhibit fibrinolysis in hemorrhagic cesarean section.

Trial registration

ClinicalTrials.gov, ID: NCT02797119. Registered on 13 June 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2420-7) contains supplementary material, which is available to authorized users.

Amniotic fluid embolism: an interdisciplinary challenge: epidemiology, diagnosis and treatment

BACKGROUND

Amniotic fluid embolism (AFE) is a life-threatening obstetric complication that arises in 2 to 8 of every 100 000 deliveries. With a mortality of 11% to 44%, it is among the leading direct causes of maternal death. This entity is an interdisciplinary challenge because of its presentation with sudden cardiac arrest without any immediately obvious cause, the lack of specific diagnostic tests, the difficulty of establishing the diagnosis and excluding competing diagnoses, and the complex treatment required, including cardio - pulmonary resuscitation.

METHOD

We selectively reviewed pertinent literature published from 2000 to May 2013 that was retrieved by a PubMed search.

RESULTS

The identified risk factors for AFE are maternal age 35 and above (odds ratio [OR] 1.86), Cesarean section (OR 12.4), placenta previa (OR 10.5), and multiple pregnancy (OR 8.5). AFE is diagnosed on clinical grounds after the exclusion of other causes of acute cardiovascular decompensation during delivery, such as pulmonary thromboembolism or myocardial infarction. Its main clinical features are severe hypotension, arrhythmia, cardiac arrest, pulmonary and neurological manifestations, and profuse bleeding because of disseminated intravascular coagulation and/or hyperfibrinolysis. Its treatment requires immediate, optimal interdisciplinary cooperation. Low-level evidence favors treating women suffering from AFE by securing the airway, adequate oxygenation, circulatory support, and correction of hemostatic disturbances. The sudden, unexplained death of a pregnant woman necessitates a forensic autopsy. The histological or immunohistochemical demonstration of formed amniotic fluid components in the pulmonary bloodflow establishes the diagnosis of AFE.

CONCLUSION

AFE has become more common in recent years, for unclear reasons. Rapid diagnosis and immediate interdisciplinary treatment are essential for a good outcome. Establishing evidence-based recommendations for intervention is an important goal for the near future.

Coagulopathy following venous air embolism: a disastrous consequence -a case report-

Venous air embolism (VAE) is a life-threatening complication of some surgical procedures. Though occurrence of VAE is frequent during neurosurgical procedures, coagulopathy following VAE has not previously been reported. Coagulation abnormalities are more commonly reported associated with fat or amniotic fluid embolism, but rarely with VAE. We present a case of massive VAE in sitting position leading to fatal coagulopathy even after successful resuscitation following the event. Coagulation abnormalities and bleeding can produce catastrophic consequences in neurosurgical patients. This report emphasizes the possibility of this potentially fatal complication in patients who have sustained a massive VAE.

Algorithm-based coagulation management of catastrophic amniotic fluid embolism

Amniotic fluid embolism (AFE) is a rare, but often catastrophic, complication of pregnancy and associated with severe coagulopathy. We present an algorithm-based approach in managing coagulopathy and hemorrhage in a fatal case of histopathologically proven AFE. Thrombelastometry was used for rapid evaluation of the coagulation status. Stop of extensive hyperfibrinolysis with tranexamic acid, stabilization of initial clot formation with high-dose fibrinogen and platelet transfusions, and use of prothrombin complex concentrate together with a 1: 1 transfusion regimen of red packed cells and fresh frozen plasma was successful to control diffuse bleeding and restore clot firmness after hysterectomy. Stable clotting situation was maintained despite further clinical deterioration and development of multiple organ failure in this patient.

Emergencies associated with pregnancy and delivery: peripartum hemorrhage

INTRODUCTION

Peripartum hemorrhage is one of the leading causes of maternal death worldwide (25%).

METHODS

Selective literature review, including international guidelines, for assessment of the causes and optimal management of this condition.

RESULTS

The major causes of hemorrhage are uterine atony, placenta previa, and abruptio placentae. The diagnosis of hemorrhage is suspected from its clinical manifestations and confirmed by ultrasonography. In placenta previa, the placenta is implanted in the lower uterine segment and may cover the internal cervical os. Placenta previa is more common in older and multiparous mothers, as well as in mothers who have previously undergone a cesarean section. Placental abruption is defined as separation of the placenta from the uterine wall before delivery of the infant. The risk factors for this condition include preeclampsia, advanced maternal age, and trauma. When it presents with manifestations of acute blood loss, premature abruption placentae must be diagnosed rapidly and treated without delay to save the life of the mother and child. A rare, but highly lethal, cause of bleeding is amniotic fluid embolism, which manifests itself with sudden and unexplained peripartum respiratory distress and cardiovascular collapse. Amniotic fluid embolism is associated with high fetal and maternal mortality (20% and 60% to 80%, respectively) even when it is optimally treated.

DISCUSSION

Peripartum hemorrhage is an important source of maternal and fetal morbidity and mortality. The prognosis for both mother and child can be markedly improved if the risk factors for hemorrhage are recognized and the problem is treated rapidly and appropriately when it arises.

Blutungen während der Schwangerschaft

Hemorrhaging during pregnancy is often fulminant and life-threatening for mother and child. Of maternal deaths occurring during pregnancy, 25% are caused by hemorrhaging. All physicians involved in the interdisciplinary treatment of hemorrhaging during pregnancy need to be familiar with the specific pathophysiology of hemostatic changes during pregnancy, e.g. elevated hemostatic capacity, reduced anti-coagulation activity and severe alterations of the fibrinolysis system. Therapists must be able to perform a consequent, goal-directed interdisciplinary approach to prevent adverse maternal and fetal outcomes. The major issues of therapy are causal obstetric treatment of the bleeding, early detection and therapy of hyperfibrinolysis, optimization of fibrinogen and platelet levels and knowledge of the possibilities of a targeted coagulation therapy.

Closing the gap between decision and delivery—Amniotic fluid embolism with severe cardiopulmonary and haemostatic complications with a good outcome

Perimortem caesarean section is very rare, mostly resulting in high mortality of mother and/or fetus. We report a case of successful resuscitation of both mother and newborn following maternal cardiac arrest prior to delivery. Postoperative outcome was complicated by severe bleeding and coagulopathy following fibrinolysis and subcapsular hepatic haematoma. We consider a fast reaction time based on a special in-hospital emergency team for immediate caesarean section and an aggressive management of coagulopathy as major factors that led to both patients recovery without neurological sequelae.