Amniotic fluid embolism: analysis of the national registry

Causes of Perioperative Cardiac Arrest: Mnemonic, Classification, Monitoring, and Actions

Perioperative cardiac arrest (POCA) is a catastrophic complication that requires immediate recognition and correction of the underlying cause to improve patient outcomes. While the hypoxia, hypovolemia, hydrogen ions (acidosis), hypo-/hyperkalemia, and hypothermia (Hs) and toxins, tamponade (cardiac), tension pneumothorax, thrombosis (pulmonary), and thrombosis (coronary) (Ts) mnemonic is a valuable tool for rapid differential diagnosis, it does not cover all possible causes leading to POCA. To address this limitation, we propose using the preload-contractility-afterload-rate and rhythm (PCARR) construct to categorize POCA, which is comprehensive, systemic, and physiologically logical. We provide evidence for each component in the PCARR construct and emphasize that it complements the Hs and Ts mnemonic rather than replacing it. Furthermore, we discuss the significance of utilizing monitored variables such as electrocardiography, pulse oxygen saturation, end-tidal carbon dioxide, and blood pressure to identify clues to the underlying cause of POCA. To aid in investigating POCA causes, we suggest the Anesthetic care, Surgery, Echocardiography, Relevant Check and History (A-SERCH) list of actions. We recommend combining the Hs and Ts mnemonic, the PCARR construct, monitoring, and the A-SERCH list of actions in a rational manner to investigate POCA causes. These proposals require real-world testing to assess their feasibility.

Anesthetic Considerations and Outcomes in Amniotic Fluid Embolism: A Retrospective Study over a 15-Year Period

(1) Background: A rare and unexpected consequence of childbirth, labor, or the immediate postpartum period is amniotic fluid embolism (AFE). This study aims to identify AFE cases during or immediately after birth from anesthetic management perspectives. Secondary goals include assessing patient clinical features, obstetric care techniques, birth outcomes, and case survival. (2) Methods: A retrospective observational study assessed AFE patients hospitalized in three Romanian clinical institutions from October 2007 to April 2023. Based on the Society of Maternal-Fetal Medicine (SMFM) criteria, we diagnosed 11 AFE patients. (3) Results: AFE occurred in eight cases (73%) during peripartum, two (18%) within 30 min after placental delivery, and 1 (9%) during a scheduled cesarean surgery. Only one of six cardiorespiratory arrest patients responded to external cardiac massage, while the other five (83%) needed defibrillation. The patients received, on average, five units of red blood cells, six of fresh frozen plasma, and two of activated platelets. Six patients (55%) received factor VIIa infusions. Maternal mortality was 36.3%. Six neonates (75%) needed neonatal resuscitation, and two (25%) died on the second and third days. (4) Conclusions: AFE management necessitates a multidisciplinary approach and the incorporation of advanced life support techniques to optimize outcomes for both the mother and newborn.

Acute Respiratory Failure in Pregnancy

Respiratory failure may affect up to 1 in 500 pregnancies, due to pregnancy-specific conditions, conditions aggravated by the pregnant state, or other causes. Management during pregnancy is influenced by altered maternal physiology, and the presence of a fetus influencing imaging, and drug therapy choices. Few studies have addressed the approach to invasive mechanical ventilatory management in pregnancy. Hypoxemia is likely harmful to the fetus, but precise targets are unknown. Hypocapnia reduces uteroplacental circulation, and some degree of hypercapnia may be tolerated in pregnancy. Delivery of the fetus may be considered to improve maternal respiratory status but improvement does not always occur.

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: a reappraisal

OBJECTIVES

Using cases from our own experience and from the published literature on amniotic fluid embolism (AFE), we seek to improve on existing criteria for diagnosis and discern associated risk factors. Additionally, we propose a novel theory of pathophysiology.

METHODS

This retrospective case review includes eight cases of AFE from two hospital systems and 21 from the published literature. All cases were evaluated using the modified criteria for research reporting of AFE by Clark et al. in Am J Obstet Gynecol, 2016;215:408-12 as well as our proposed criteria for diagnosis. Additional clinical and demographic characteristics potentially correlated with a risk of AFE were included and analyzed using descriptive analysis.

RESULTS

The incidence of AFE was 2.9 per 100,000 births, with five maternal deaths in 29 cases (17.2 %) in our series. None of the cases met Clark's criteria while all met our criteria. 62.1 % of patients were over the age of 32 years and two out of 29 women (6.9 %) conceived through in-vitro fertilization. 6.5 % of cases were complicated by fetal death. Placenta previa occurred in 13.8 %. 86.2 % of women had cesarean sections of which 52.0 % had no acute maternal indication.

CONCLUSIONS

Our criteria identify more patients with AFE than others with a low likelihood of false positives. Clinical and demographic associations in our review are consistent with those previously reported. A possible relationship between cesarean birth and risk of AFE was identified using our criteria. Additionally, we propose a new hypothesis of pathophysiology.

Amniotic fluid embolism: A case report of good outcome with timely intensive multidisciplinary team involvement

OBJECTIVE

Amniotic fluid embolism is one of the most serious pregnancy complications. It can cause sudden maternal collapse with high mortality and morbidity. We present a case report regarding the important of prompt decision making and multidisciplinary team work for management of amniotic fluid embolism to yield favorable maternal and neonatal outcome.

CASE REPORT

This is a 35-year-old, gravida 2, para 1, woman underwent labor induction at gestational age of 37 + 6 weeks due to elective induction. She had sudden facial cyanosis and shortness of breath right after artificial rupture of membrane. Prompt decision of urgent cesarean section, aggressive and timely massive blood transfusion and multidisciplinary team work had spared patient from extracorporeal membrane oxygenation placement and prolonged hospitalization. A male infant was born with Apgar score 3' -> 5' with estimate body weight of 2958 gm; he was hospitalized for 10 days and no other complications was found at follow up pediatric outpatient clinic.

CONCLUSION

One of the most dreadful, but rare pregnancy complications is amniotic fluid embolism (AFE). It can cause serious maternal and neonatal morbidity and mortality. Rapid recognition and multidisciplinary team management are essential to maternal and neonatal prognosis.

Medical Emergencies in the Pregnant Patient

This review article provides a comprehensive overview of common medical emergencies that can occur in pregnant patients. We summarize the key diagnostic and management steps for each emergency to assist health care professionals in identifying and treating these potentially life-threatening conditions. The medical emergencies discussed in this article include postpartum hemorrhage; hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome; acute fatty liver of pregnancy; amniotic fluid embolism; pulmonary embolism; acute respiratory distress syndrome; and shock. Each condition is described in detail, with a focus on the clinical presentation, diagnostic workup, and treatment options. The information presented in this review article is based on current best practices and guidelines from leading medical organizations. We hope this article will serve as a valuable resource for health care professionals who care for pregnant patients and help improve outcomes for these patients in emergency situations.

Nontrombotic Pulmonary Embolism: Different Etiology, Same Significant Consequences

Nontrombotic pulmonary embolism represents the embolization of different types of materials (cells, organisms, gas, foreign material) into pulmonary circulation. The disease is uncommon, and clinical presentation together with laboratory findings are nonspecific. Its pathology is usually misdiagnosed based on imaging findings as pulmonary thromboembolism, but the correct diagnosis is essential because different therapeutic approaches are required. In this context, knowledge of the risk factors associated with nontrombotic pulmonary embolism and specific clinical symptoms is fundamental. Our objective was to discuss the specific features of the most common etiologies of nontrombotic pulmonary embolism, gas, fat, amniotic fluid, sepsis and tumors, to provide assistance for a rapid and correct diagnosis. Because the most common etiologies are iatrogenic, knowledge of the risk factors could be an important tool for prevention or rapid treatment if the disease develops during different procedures. The diagnosis of nontrombotic pulmonary embolisms represent a laborious challenge, and endeavors should be made to prevent development and increase awareness of this disease.

Acute respiratory distress and amniotic fluid embolism in pregnancy

Respiratory failure in pregnant and postpartum women is uncommon, but it is one of the leading causes of maternal admission into the intensive care unit and is associated with high mortality. The underlying causes include sequelae of underlying medical conditions, such as congenital heart diseases, but it is more often related to acute respiratory distress syndrome from obstetric complications like pre-eclampsia, effect of treatment like tocolysis, coincidental to pregnancy like transfusion-related acute lung injury, and accidental like amniotic fluid embolism. The pathophysiological mechanisms involved in many of these conditions remain to be clearly established, but maternal inflammatory response and activation of the immune and complement systems appear to play leading roles. Prompt recognition of maternal respiratory distress and related manifestations and aggressive and adequate supportive treatment, especially cardiopulmonary resuscitation, ventilation, maintenance of circulation, and timely termination of the pregnancy, play key roles in achieving survival of both mother and foetus.

Obstetric Disorders and Critical Illness

In this article, we discuss some of the more common obstetric-related conditions that can lead to critical illness and require management in an ICU. These include the hypertensive disorders of pregnancy, postpartum hemorrhage, hemolysis, elevated liver enzymes, and low platelet syndrome, acute fatty liver of pregnancy, amniotic fluid embolism, and peripartum cardiomyopathy. We also discuss pulmonary embolism and Covid-19. Despite not being specific to obstetric patients, pulmonary embolism is a common, life-threatening diagnosis in pregnancy with particular risks and management aspects. Covid-19 does not seem to occur with higher frequency in pregnant women, but it leads to higher rates of ICU admissions and mechanical ventilation in pregnant women than in their nonpregnant peers. Its prevalence during our current global pandemic makes it important to discuss in this article. We provide a basis for critical care physicians to be engaged in informed conversations and management in a multidisciplinary manner with other relevant providers in the care of critically ill pregnant and postpartum women.

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.

Recurrent Cardiac Arrests Due to Amniotic Fluid Embolism

Amniotic fluid embolism (AFE) is a rare but devastating complication of pregnancy and is associated with high morbidity and mortality. Identifiable maternal risk factors for AFE include older age, multiparity, cesarean section, and placenta previa, while fetal factors include male gender, fetal distress, and death. AFE presents with respiratory distress, seizure, and circulatory collapse and can be complicated with disseminated intravascular coagulopathy, multiorgan failure, and death. In our case, we present a patient who underwent elective cesarean section for placenta previa, which was complicated by sudden cardiac arrest immediately after delivering the placenta in the operating theatre followed by disseminated intravascular coagulation (DIC). The patient developed massive post-partum hemorrhage secondary to the underlying DIC, which required a massive blood transfusion along with platelets, fresh frozen plasma (FFP), and tranexamic acid. The Society of Maternal-Fetal Medicine proposed criteria for the diagnosis of AFE, which include clinical features and laboratory findings. The presence of a DIC picture is considered to be the hallmark finding that helps to differentiate between AFE and other conditions with similar presentation. Treatment of amniotic fluid embolism depends on early recognition and supportive care. 

Successful ECMO-assisted open chest cardiopulmonary resuscitation in a postpartum patient with delayed amniotic fluid embolism

Background

Amniotic fluid embolism (AFE) is a rare but potentially dangerous severe obstetrics complication, which is accompanied by an incidence between 1.9 and 6.1 per 100,000 births.

Case presentation

Here, we report an AFE case after cesarean delivery diagnosed on a cardiac arrest complicated by acute respiratory distress syndrome and coagulopathy. Diagnosis, risk factors and pathophysiology for AFE have been fully discussed, besides, extracorporeal membrane oxygenation in the early management of cardiac arrest was used, describing the indication, efficacy and successful performed of open-chest cardiopulmonary resuscitation for the patient.

Conclusion

In AFE with cute cardiovascular collapse, extracorporeal membrane oxygenation support can be considered as the alternative therapies.

The rare but dangerous amniotic fluid embolish after cesarean delivery was diagnosed.

A cardiac arrest accompanied by acute respiratory distress syndrome and coagulopathy was recorded.

Diagnosis, risk factors and pathophysiology for amniotic fluid embolish in this case were detailly discussed.

A case report of early application of veno-arterial extracorporeal membrane oxygenation in amniotic fluid embolism

RATIONALE

Amniotic fluid embolism (AFE) is a rare obstetrical complication and is a leading cause of maternal death in developed countries. Despite the development of supportive therapeutic measures, the mortality rate remains high.

PATIENT CONCERNS

A 38-year-old nulliparous pregnant woman, who underwent in vitro fertilization-embryo transfer, was admitted for labor at 37 weeks' gestation. Approximately 30 minutes after delivery of the placenta, the puerpera developed postpartum hemorrhage with uterine atony. Soon after, the patient experienced hypotension, repeated cardiac arrest, refectory hypoxia, and disseminated intravascular coagulopathy.

DIAGNOSIS

AFE is diagnosed clinically. The pregnant woman in this case fulfilled the diagnostic criteria for AFE: acute hypotension, cardiac arrest, acute hypoxia, and coagulation disorders within approximately 30 minutes after delivery of the placenta.

INTERVENTIONS

The patient was intubated, connected to a ventilator, and was administered a high dose of vasoactive drugs to maintain blood pressure and underwent an emergency hysterectomy. Considering the risk for recurrent cardiac arrest and severe refractory hypoxia, venoarterial extracorporeal membrane oxygenation was initiated and discontinued as soon as cardiac function was restored based on serial bedside ultrasound assessment.

OUTCOMES

The patient stabilized on day 7 in the intensive care unit and was transferred to the obstetrics ward and, 1 week later, was discharged with no complications. Two months later, follow-up revealed that the patient was in good condition.

LESSON

Serial bedside ultrasound was crucial for assessing cardiac function and optimal weaning. Timely application of venoarterial extracorporeal membrane oxygenation and weaning was significant to avoid the occurrence of complications and improve long-term outcomes.

Postpartum Respiratory Depression

Postpartum respiratory depression is a complex, multifactorial issue that encompasses a patient's baseline preexisting conditions, certain pregnancy-specific conditions or complications, as well as the iatrogenic element of various medications given in the peripartum period. In this review, we discuss many of these factors including obesity, sleep-disordered breathing, chronic lung disease, neuromuscular disorders, opioids, preeclampsia, peripartum cardiomyopathy, postpartum hemorrhage, amniotic fluid embolism, sepsis, acute respiratory distress syndrome (ARDS), and medications such as analgesics, sedatives, anesthetics, and magnesium. Current recommendations for screening, treatment, and prevention are also discussed.

A Detailed Review of Critical Care Considerations for the Pregnant Cardiac Patient

Maternal cardiovascular disease is a leading cause of maternal death worldwide and recently, maternal mortality has increased secondary to cardiovascular causes. Maternal admissions to critical care encompass 1%-2% of all critical care admissions, and although not common, the management of the critically ill pregnant patient is complex. Caring for the critically ill pregnant cardiac patient requires integration of pregnancy-associated physiologic changes, understanding pathophysiologic disease states unique to pregnancy, and a multidisciplinary approach to timing around delivery as well as antenatal and postpartum care. Herein we describe cardiorespiratory changes that occur during pregnancy and the differential diagnosis for cardiorespiratory failure in pregnancy. Cardiorespiratory diseases that are either associated or exacerbated by pregnancy are highlighted with emphasis on perturbations secondary to pregnancy and appropriate management strategies. Finally, we describe general management of the pregnant cardiac patient admitted to critical care.

State-of-the-Art on Biomarkers for Anaphylaxis in Obstetrics

Anaphylaxis is an unpredictable systemic hypersensitivity reaction and constitutes a high risk of maternal and fetal morbidity and mortality when occurring during pregnancy. Currently, the acute management of anaphylaxis is based on clinical parameters. A total serum tryptase is only used to support an accurate diagnosis. There is a need to detect other biomarkers to further assess high-risk patients in obstetrics. Our objective is to present biomarkers in this complex interdisciplinary approach beyond obstetrician and anaesthetic management. Candidate biomarkers derive either from mediators involved in immunopathogenesis or upcoming molecules from systems biology and proteomics. Serum tryptase is determined by singleplex immunoassay method and is important in the evaluation of anaphylactic mast cell degranulation but also in the assessment of other risk factors for anaphylaxis such as systemic mastocytosis. Another category of biomarkers investigates the IgE-mediated sensitization to triggers potentially involved in the etiology of anaphylaxis in pregnant women, using singleplex or multiplex immunoassays. These in vitro tests with natural extracts from foods, venoms, latex or drugs, as well as with molecular allergen components, are useful because in vivo allergy tests cannot be performed on pregnant women in such a major medical emergency due to their additional potential risk of anaphylaxis.

The role of echocardiography in amniotic fluid embolism: a case series and review of the literature

PURPOSE

Amniotic fluid embolism (AFE) is a rare, but often fatal condition characterized by sudden hemodynamic instability and coagulopathy occurring during labour or in the early postpartum period. As the mechanisms leading to shock and the cardiovascular effects of AFE are incompletely understood, the purpose of this case series is to describe how AFE presents on echocardiography and review limited reports in the literature.

CLINICAL FEATURES

We describe three cases of AFE at the Jewish General Hospital, a tertiary care centre in Montreal, Canada. All cases met the Clark diagnostic criteria, which comprise 1) sudden cardiorespiratory arrest or both hypotension and respiratory compromise, 2) disseminated intravascular coagulation, 3) clinical onset during labour or within 30 min of delivery of the placenta, and 4) absence of fever. Two patients had a cardiac arrest and the third developed significant hypotension and hypoxia. In all patients, point-of-care echocardiography at the time of shock revealed signs of right ventricular failure including a D-shaped septum, acute pulmonary hypertension, and right ventricular systolic dysfunction.

CONCLUSION

This case series and literature review of AFE emphasizes the importance of echocardiography in elucidating the etiology of maternal shock. The presence of right ventricular failure may be considered an important criterion to diagnose AFE.

Early Diagnosis of the Cardiopulmonary Collapse Type of Amniotic Fluid Embolism with Obstetrical Disseminated Intravascular Coagulation during Elective Cesarean Section : A Case Report

Two types of amniotic fluid embolism (AFE) have been described : cardiopulmonary collapse type and disseminated intravascular coagulation (DIC) type, with the latter proposed as uterine type. This report describes a healthy 28-year-old woman who developed AFE during a cesarean section. Because of a previous cesarean section, the patient underwent an elective cesarean section, under combined spinal-epidural anesthesia, at 38 weeks of pregnancy. She began coughing 5 minutes after delivery of the fetus, subsequently becoming unconscious and developing glossoptosis and bradycardia. Her blood pressure decreased to 76/43 mmHg, and AFE was suspected. Her uterus was atonic, and she experienced persistent noncoagulant bleeding, with a final blood loss of 6300 ml. Considerable blood transfusion was required. The patient survived, and she and her baby were discharged without any sequelae on the eighth postoperative day. This patient met the Japanese criteria for clinical AFE, with an obstetrical DIC score of 21 meeting the criteria for obstetrical DIC. Early diagnosis and treatment likely resulted in patient survival. J. Med. Invest. 67 : 207-210, February, 2020.

Radiologic mimics of pulmonary embolism

The diagnosis of pulmonary embolism (PE) is often made more challenging by the presence of diseases that can mimic thromboembolic disease. There is no specific or sensitive constellation of clinical signs or symptoms that can be used to diagnose PE. Ventilation/perfusion scans can have false-positive findings related to mediastinal conditions that can compress the pulmonary arteries, and pulmonary hemorrhage can resemble PE on V/Q scanning with potentially devastating consequences if anticoagulation is started. CT-scan related issues l eading to potential false-positive diagnoses range from inadequate imaging technique, to systemic-pulmonary shunting, to non-thrombotic occlusion of pulmonary arteries by tumor, septic emboli, and emboli of fat, air, and foreign material, as well as vasculitic processes. Careful assessment of the patient and consideration of these potential mimickers is imperative to correct diagnosis of this potentially life-threatening condition.

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

Supplemental Digital Content is available in the text.

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.

Fibrinogen may aid in the early differentiation between amniotic fluid embolism and postpartum haemorrhage: a retrospective chart review

This study aimed to determine whether blood loss and fibrinogen can differentiate amniotic fluid embolism (AFE) from postpartum haemorrhage (PPH). This retrospective case–control study included nine patients with clinical AFE (“AFE group”) and 78 patients with PPH managed at our tertiary care perinatal centre between January 2014 and March 2016. Patients meeting the Japanese diagnostic criteria for AFE were stratified into cardiopulmonary collapse-type AFE and disseminated intravascular coagulation (DIC)-type AFE groups. The relationship between blood loss and fibrinogen at onset was examined to compare DIC severity. Vital signs at onset were not significantly different. The AFE group had significantly less blood loss at onset (1506 mL vs 1843 mL, P = 0.0163), significantly more blood loss 2 h post-onset (3304 mL vs 1996 mL, P < 0.0001) and more severe coagulopathy and fibrinolysis. The blood loss/fibrinogen (B/F) ratio at onset was significantly higher in the DIC-type AFE group (23.15 ± 8.07 vs 6.28 ± 3.35 mL dL/mg, P < 0.0001). AFE was complicated by catastrophic DIC irrespective of blood loss at onset. Fibrinogen exhibited the strongest correlation among test findings at onset. The B/F ratio may help differentiate PPH from DIC-type AFE and diagnose clinical AFE, facilitating optimal replacement of coagulation factors during the early stages.

Disseminated intravascular coagulation type of amniotic fluid embolism: a challenging case report with favorable outcome

Amniotic fluid embolism (AFE) is an unforeseeable, life-threatening complication of pregnancy and child birth. Although rare in an absolute sense, most contemporary series of maternal deaths from developed countries report AFE as a leading cause of mortality in the pregnant population. It has a heterogeneous presentation. This clinical heterogeneity makes the diagnosis of AFE difficult based on a beam of clinical and para-clinical arguments. Rapid diagnosis and immediate interdisciplinary treatment are essential for a good outcome. The present is a case of AFE with a disseminated intravascular coagulation (DIC) and a cardiorespiratory collapse following a vaginal delivery.

Society for Maternal-Fetal Medicine Special Statement: Checklist for initial management of amniotic fluid embolism

Amniotic fluid embolism is a rare syndrome characterized by sudden cardiorespiratory collapse during labor or soon after delivery. Because of its rarity, many obstetrical providers have no experience in managing amniotic fluid embolism and may therefore benefit from a cognitive aid such as a checklist. We present a sample checklist for the initial management of amniotic fluid embolism based on standard management guidelines. We also suggest steps that each facility can take to implement the checklist effectively.

Biochemical effects of intraoperative cell salvage and autotransfusion during cesarean section: A prospective pilot study

AIM

Intraoperative cell salvage and autotransfusion (ICSA) is a useful technique for women undergoing cesarean sections who are predicted to experience significant bleeding. This method can reduce allogeneic transfusions as well as its associated risks and costs. Amniotic fluid embolism (AFE) is an abnormal maternal response to ICSA similar to the classic systemic inflammatory response syndrome, but its mechanism is not well understood. This study was conducted to investigate the biochemical aspects of AFE.

METHODS

A prospective case-controlled pilot study was conducted in a general perinatal hospital in Japan. ICSA was performed using a two-step retransfusion process. Blood samples were collected presurgery, immediately postsurgery, and 24 h after surgery. Changes in sialyl Tn antigen (STN), complement C3 and C4, fibrinogen, and fibrin degradation product and D-dimer, C1 esterase inhibitor, and interleukin-8 (all considered AFE-related markers) activities were compared between patients who underwent cesarean sections with ICSA (ICSA group) versus without ICSA (control group).

RESULTS

Fibrinogen levels were significantly lower in the ICSA group than in the control group before surgery but not immediately after or 24 h after surgery. D-dimer was significantly higher immediately after surgery but not 24 h later. STN was significantly lower only before surgery. None of the AFE-related markers showed significant differences between the groups after 24 h. No adverse events were observed in the ICSA group.

CONCLUSIONS

There is no clinical evidence that ICSA alters the biochemical statuses of AFE-related markers in a manner that could lead to adverse maternal responses.

Reference range for C1-esterase inhibitor (C1 INH) in the third trimester of pregnancy

OBJECTIVES

The objectives of this study were to (i) establish the reference range and mean value for normal levels of C1-esterase inhibitor (C1 INH) during pregnancy, and (ii) investigate the association between C1 INH and uterine atony, as measured by blood loss at delivery.

METHODS

We prospectively studied 200 healthy pregnant women who were registered. We studied C1 INH levels in 188 women at 34 and 35 gestational weeks of pregnancy. The reference range for C1 INH during the third trimester of pregnancy was calculated using the value of C1 INH that was determined at registration.

RESULTS

The mean value of C1 INH was determined to be 70.3% (95% confidence interval, 68.7-71.9). While the C1 INH levels in four women were determined to be 40% lower than the calculated mean value, amniotic fluid embolism (AFE) did not occur in any of the women studied.

CONCLUSIONS

This study successfully demonstrated that a reference value for C1 INH activity can be established using the methods described herein. Further research is needed to determine whether C1 INH is involved in obstetric coagulopathy syndrome such as amniotic fluid embolism.

Continuous renal replacement therapy rescues severe haemorrhagic fever with renal syndrome in pregnancy: a case report

Background

Haemorrhagic fever with renal syndrome (HFRS) is a natural epidemic disease caused by various types of viruses of the genus Hantavirus, which are mainly transmitted by contact with the infected rodents and their droppings. Pregnancy complicated with HFRS is rare; however, adverse maternal and foetal outcomes may be noted. In this report, we describe a case involving a pregnant woman with HFRS who was in a state of multiple organ dysfunction syndrome (MODS) and was successfully treated with continuous renal replacement therapy (CRRT).

Case presentation

A 32-year-old pregnant woman at 29 weeks of gestation was hospitalised for a fever and upper respiratory tract infection due to HFRS in winter. Persistent fever, coagulation disorder, thrombocytopenia, electrolyte imbalance, abnormal liver function, and renal failure were noted during the progression of the disease. The patient was treated with CRRT. She recovered after 21 days, and delivered a live infant by caesarean section at 38 weeks of gestation. Furthermore, obvious abnormalities were not detected during the follow-up of the mother and infant at 42 days, 3 months, 6 months, and 1 year after the delivery.

Conclusions

Early diagnosis, timely application of CRRT, and comprehensive treatment may be essential for the successful treatment of patients with HFRS during pregnancy.

Amniotic fluid embolism: A rare cause of maternal collapse-A case report

High index of suspicion of amniotic fluid embolism should be considered in any intrapartum or postpartum collapse where the obvious cause of collapse is not identified.

Amniotic fluid embolism and management of coagulopathy: A case report with successful outcome

Amniotic fluid embolism (AFE) is a rare and potentially catastrophic condition unique to pregnancy. Presentation may range from subtle clinical events to sudden and fatal maternal cardiorespiratory arrest, with a reported incidence of 2–6 in 100,000 deliveries and mortality of 15–60%. Management should include immediate high-grade resuscitation for AFE presenting as cardiac arrest, involvement of multidisciplinary team, provision of adequate ventilator and circulatory support, treatment of coagulopathy precipitated by AFE, and immediate delivery of the foetus in cases of cardiac arrest. The following case report involves a patient with suspected AFE post-induction of labour with favourable maternal and neonatal outcome in our local setting. The management of coagulopathy in AFE is further discussed, including use of massive transfusion protocols, pharmacological agents and recombinant factor VIIa.

Extracorporeal Membrane Oxygenation for Amniotic Fluid Embolism-Induced Cardiac Arrest in the First Trimester of Pregnancy: A Case Report

Supplemental Digital Content is available in the text.

Amniotic fluid embolism is a rare obstetric emergency that can be accompanied by profound hypoxemia, coagulopathy, hemorrhage, and cardiogenic shock. Extracorporeal membrane oxygenation may provide a rescue strategy in amniotic fluid embolism with cardiopulmonary collapse. Approaches to anticoagulation must be balanced against the risk of hemorrhage with concomitant coagulopathy. Although extracorporeal membrane oxygenation has been described for cardiopulmonary collapse in the setting of amniotic fluid embolism, its initiation as a bridge to hemostasis and cardiopulmonary recovery in amniotic fluid embolism–induced hemorrhagic and cardiogenic shock remains a novel resuscitation strategy.

Sudden onset of syncope and disseminated intravascular coagulation at 14 weeks of pregnancy: a case report

BACKGROUND

Amniotic fluid embolism (AFE), also known as anaphylactoid syndrome of pregnancy (ASP), typically occurs during labor and may result in cardiorespiratory collapse and disseminated intravascular coagulation (DIC). There are reports describing less typical presentations of AFE/ASP in which patients do not necessarily have the classic triad of hypoxia, hypotension, and coagulopathy. AFE/ASP rarely occurs in the absence of labor, but such cases may involve medical or surgical abortion, spontaneous miscarriage, or obstetrical procedures including amniocentesis and amnioinfusion. There are, however, no previously reported cases of AFE/ASP with sudden loss of consciousness and disseminated intravascular coagulation occurring during early pregnancy, in the absence of any intervention or obstetric event.

CASE PRESENTATION

A 32-year-old G3P2 Japanese woman had sudden-onset syncope at 14 weeks' gestation. On arrival at our hospital, her level of consciousness was severely disturbed as determined by the Glasgow Coma Scale. Although her vital signs were initially stable, blood samples collected intravenously and by femoral artery puncture did not coagulate. A subchorionic hematoma with active extravasation of blood was apparent on contrast-enhanced computed tomography. Two hours after her arrival, she developed hypovolemic shock with progression of DIC, presumably due to intrauterine and retroperitoneal bleeding. After transfusion of blood products; treatments for DIC including the use of recombinant human soluble thrombomodulin, ulinastatin, and corticosteroids; and hysterectomy, her level of consciousness and physical condition improved remarkably. Later investigation of preoperative blood samples revealed that serum levels of AFE/ASP-associated markers were elevated. Immunohistochemical studies on the excised, unruptured uterus showed that amniotic fluid components were present inside a uterine blood vessel.

CONCLUSIONS

This is the first reported patient with sudden-onset syncope and DIC, but without apparent cardiorespiratory collapse, with the highly likely etiology of AFE/ASP occurring at the beginning of the second trimester of pregnancy and in the absence of intervention or delivery. Maternal collapse with DIC during any stage of pregnancy should be considered an AFE/ASP-associated event, even in the absence of labor or obstetric procedures. This event may occur in the presence of subchorionic hematoma alone.

Extracorporeal Life Support in Pregnancy: A Systematic Review

Background The use of extracorporeal life support (ECLS) has expanded to include unique populations such as peripartum women. This systematic review aims to (1) quantify the number of cases and indications for ECLS in women during the peripartum period reported in the literature and (2) report maternal and fetal complications and outcomes associated with peripartum ECLS. Methods and Results This review was registered in PROSPERO (CRD42018108142). MEDLINE, Embase, and CINAHL were searched for case reports, case series, and studies reporting cases of ECLS during the peripartum period that reported one or more of the following outcomes: maternal survival, maternal complications, fetal survival, and/or fetal complications. Qualitative assessment of 221 publications evaluated the number of cases, clinical details, and maternal and fetal outcomes of ECLS during the peripartum period. There were 358 women included and 68 reported fetal outcomes in cases where the mother was pregnant at the time of cannulation. The aggregate maternal survival at 30 days was 270 (75.4%) and at 1 year was 266 (74.3%); fetal survival was 44 (64.7%). The most common indications for ECLS overall in pregnancy included acute respiratory distress syndrome 177 (49.4%), cardiac failure 67 (18.7%), and cardiac arrest 57 (15.9%). The most common maternal complications included mild to moderate bleeding 66 (18.4%), severe bleeding requiring surgical intervention 48 (13.4%), and intracranial neurologic morbidity 19 (5.3%). The most commonly reported fetal complications included preterm delivery 33 (48.5%) and neonatal intensive care unit admission 19 (27.9%). Conclusions Reported rates of survival in ECLS in pregnant and postpartum women are high and major complications relatively low.

Amniotic fluid embolism syndrome: analysis of the Unites States International Registry

BACKGROUND

Incidence, risk factors, and perinatal morbidity and mortality rates related to amniotic fluid embolism remain a challenge to evaluate, given the presence of differing international diagnostic criteria, the lack of a gold standard diagnostic test, and a significant overlap with other causes of obstetric morbidity and mortality.

OBJECTIVE

The aims of this study were (1) to analyze the clinical features and outcomes of women using the largest United States-based contemporary international amniotic fluid embolism registry, and (2) to investigate differences in demographic and obstetric variables, clinical presentation, and outcomes between women with typical versus atypical amniotic fluid embolism, using previously published and validated criteria for the research reporting of amniotic fluid embolism.

MATERIALS AND METHODS

The AFE Registry is an international database established at Baylor College of Medicine (Houston, TX) in partnership with the Amniotic Fluid Embolism Foundation (Vista, CA) and the Perinatology Research Branch of the Division of Intramural Research of the NICHD/NIH/DHHS (Detroit, MI). Charts submitted to the registry between August 2013 and September 2017 were reviewed, and cases were categorized into typical, atypical, non-amniotic fluid embolism, and indeterminate, using the previously published and validated criteria for the research reporting of AFE. Demographic and clinical variables, as well as outcomes for patients with typical and atypical AFE, were recorded and compared. Student t tests, χ2 tests, and analysis of variance tables were used to compare the groups, as appropriate, using SAS/STAT software, version 9.4.

RESULTS

A total of 129 charts were available for review. Of these, 46% (59/129) represented typical amniotic fluid embolism and 12% (15/129) atypical amniotic fluid embolism, 21% (27/129) were non-amniotic fluid embolism cases with a clear alternative diagnosis, and 22% (28/129) had an uncertain diagnosis. Of the 27 women misclassified as an amniotic fluid embolism with an alternative diagnosis, the most common actual diagnosis was hypovolemic shock secondary to postpartum hemorrhage. Ten percent (6/59) of the women with typical amniotic fluid embolism had a pregnancy complicated by placenta previa, and 8% (5/61) had undergone in vitro fertilization to achieve pregnancy. In all, 66% (49/74) of the women with amniotic fluid embolism reported a history of atopy or latex, medication, or food allergy, compared to 34% of the obstetric population delivered at our hospital over the study period (P < .05).

CONCLUSION

Our data represent a series of women with amniotic fluid embolism whose diagnosis has been validated by detailed chart review, using recently published and validated criteria for research reporting of amniotic fluid embolism. Although no definitive risk factors were identified, a high rate of placenta previa, reported allergy, and conceptions achieved through in vitro fertilization was observed.

Extracorporeal Therapies for Amniotic Fluid Embolism

BACKGROUND

Amniotic fluid embolism (AFE) is a catastrophic disease with significant mortality. Because the cardiopulmonary dysfunction associated with AFE is self-limited, the disease could be well suited to the use of extracorporeal therapies.

CASE

A woman progressed into cardiac arrest immediately after an elective cesarean delivery. Owing to severe hypoxemia and hypotension, AFE was suspected and peripheral venoarterial extracorporeal membrane oxygenation was quickly initiated. Subsequent evolution was complicated by intrabdominal bleeding, which required massive transfusion and multiple surgeries. The patient recovered well, with a healthy newborn. We have identified 19 similar cases in the literature and present their outcomes as a series.

CONCLUSION

Extracorporeal therapies can support severely ill women affected by AFE and could be considered even in the presence of disseminated intravascular coagulation and bleeding.

Successful resuscitation by using extracorporeal membrane oxygenation in a patient with amniotic fluid embolism: a case report

Amniotic fluid embolism (AFE) is a rare disease, but it is a potentially fatal condition, as well as a leading cause of unpredictable maternal death in developed countries. The typical clinical symptoms of AFE include hypoxia, hypotension, and coagulopathy, and with rapid progression, it may cause cardiac arrest and death. We report a case of sudden hemodynamic instability due to amniotic fluid embolism, which was successfully treated with veno-arterial extracorporeal membrane oxygenation (ECMO). A 39-year-old woman was scheduled for delivery at 38 weeks and 2 days of gestation. During labor, sudden generalized tonic-clonic seizures developed, followed by dyspnea and cyanosis. Despite immediate cesarean section being performed, she became hypoxemic and experienced cardiovascular collapse. ECMO was promptly applied, and the patient became stable 8 days after cesarean section. ECMO appears to be an appropriate treatment option for catastrophic amniotic fluid embolism.

Case report of amniotic fluid embolism coagulopathy following abortion; use of viscoelastic point-of-care analysis

BACKGROUND

Amniotic fluid embolism (AFE) is a rare, life threatening obstetric complication, often associated with severe coagulopathy. Induced abortions are extremely safe procedures however complications including AFE can occur.

CASE PRESENTATION

A 29-year-old previously healthy woman, gravida 1 para 0, presented for a scheduled second trimester induced abortion via dilation and evacuation at 22-weeks gestation. The case was complicated by a suspected AFE with associated profound coagulopathy. Viscoelastic point-of-care coagulation analysis was used to successfully and swiftly guide management of her coagulopathy.

CONCLUSION

AFE can occur in the setting of induced abortion. This case report suggests viscoelastic point-of-care coagulation analyzers may aid in the management of pregnancy-related coagulopathy by providing faster coagulation assessment than laboratory testing, and facilitating timely, targeted management of coagulopathy.

Successful treatment of amniotic fluid embolism complicated by disseminated intravascular coagulation with rivaroxaban: A case report

RATIONALE

An amniotic fluid embolism (AFE) is a rare, lethal syndrome that is commonly associated with disseminated intravascular coagulation (DIC). Anticoagulation therapy is the most important strategy to inhibit excessive activation of the coagulation cascade in patients with AFE and DIC. At present, treatment of AFE with rivaroxaban has not been reported.

PATIENT CONCERNS

We report a 37-year-old woman (gravida 2, para 1) at 39 weeks' gestation with irregular contractions of the uterus was admitted to the obstetrical department. Ten minutes after the spontaneous rupture of the membranes, the patient complained of dyspnea and dysphoria and exhibited cyanosis of her lips. The patient's blood pressure decreased and heart rate increased rapidly, and 2100 mL of unclotted blood flowed from her vagina within 1 hour. Her platelet count dropped to 21 × 10/L, and the results from routine coagulation tests, and D-dimer and fibrin degradation product tests were obviously abnormal.

DIAGNOSES

According to the current research consensus, AFE with DIC should be considered immediately when sudden cardiovascular collapse occurs around the time of labor and delivery, followed by the development of coagulopathy and hemorrhage.

INTERVENTIONS

In addition, the variety of supportive treatments, rivaroxaban was used in anticoagulant therapy.

OUTCOMES

At follow-up 30 and 60 days, there were no complaints of discomfort or abnormal laboratory assays. The patient recovered completely.

LESSONS

This case highlights that rivaroxaban, as a direct inhibitor of activated factor Xa, demonstrates a good therapeutic efficacy for treating AFE with DIC.

Pulmonary amniotic fluid embolism in a rhesus macaque (Macaca mulatta)

A pregnant female rhesus macaque died spontaneously during stage two labor. Gross and histopathologic findings included severe pulmonary edema, with low numbers of blood vessels containing pale basophilic mucinous material (Alcian Blue positive and PTAH negative), consistent with intravascular amniotic fluid-derived mucin resulting in pulmonary amniotic fluid embolism.

Amniotic fluid embolism: A puzzling and dangerous obstetric problem

In a Perspective, Sarka Lisonkova and Michael Kramer discuss the accompanying study by Kathryn Fitzpatrick and co-authors on management of amniotic fluid embolism.

No. 360-Induced Abortion: Surgical Abortion and Second Trimester Medical Methods

OBJECTIVE

This guideline reviews evidence relating to the provision of surgical induced abortion (IA) and second trimester medical abortion, including pre- and post-procedural care.

INTENDED USERS

Gynaecologists, family physicians, nurses, midwives, residents, and other health care providers who currently or intend to provide and/or teach IAs.

TARGET POPULATION

Women with an unintended or abnormal first or second trimester pregnancy.

EVIDENCE

PubMed, Medline, and the Cochrane Database were searched using the key words: first-trimester surgical abortion, second-trimester surgical abortion, second-trimester medical abortion, dilation and evacuation, induction abortion, feticide, cervical preparation, cervical dilation, abortion complications. Results were restricted to English or French systematic reviews, randomized controlled trials, clinical trials, and observational studies published from 1979 to July 2017. National and international clinical practice guidelines were consulted for review. Grey literature was not searched.

VALUES

The quality of evidence in this document was rated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology framework. The summary of findings is available upon request.

BENEFITS, HARMS, AND/OR COSTS

IA is safe and effective. The benefits of IA outweigh the potential harms or costs. No new direct harms or costs identified with these guidelines.

Resuscitation of the Pregnant Patient

Many health care providers lack familiarity with maternal physiologic changes and the distinctive underlying etiology of cardiac arrest in pregnancy. Knowledge of what changes are expected in pregnancy and an understanding of how to adapt clinical practice is essential for the care of the pregnant woman in the emergency department. Amniotic fluid embolism should be recognized as a rare cause of cardiac arrest in pregnancy, characterized by the triad of cardiovascular collapse, hypoxic respiratory failure, and coagulopathy. Cardiopulmonary resuscitation should follow standard AHA ACLS guidelines. Resuscitative hysterotomy may be attempted to restore perfusion to both mother and fetus.