Amniotic fluid embolism

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.

Prenatal hypertension as the risk of eclampsia, HELLP syndrome, and critical obstetric hemorrhage

Critical bleeding is a common cause of maternal mortality in obstetric patients. However, the non-obstetric factors underlying critical obstetric bleeding remain uncertain. Therefore, this study aimed to clarify the impact of chronic hypertension on obstetric hemorrhage by evaluating a nationwide administrative database in Japan. Women who gave birth between 2018 and 2022 were enrolled. The primary outcome was critical hemorrhage requiring massive red blood cell (RBC) transfusion during childbirth. In total, 354, 299 eligible women were selected from the database. The maternal mortality rate was >1.0% among those who received a massive RBC transfusion (≥4000 cc), and this amount was used as the cutoff of the outcome. Critical hemorrhage was less frequent with elective Caesarean section (CS) compared with vaginal childbirth or emergent CS (odds ratio [OR], 0.38; 95% confidence interval, 0.30-0.47). Multiple logistic regression analysis adjusting for these obstetric risks revealed that a higher maternal age (adjusted OR [aOR] per 1 year, 1.07 [1.05-1.09]); oral medications with prednisolone (aOR, 2.5 [1.4-4.4]), anti-coagulants (aOR, 10 [5.4-19]), and anti-platelets (aOR, 2.9 [1.3-6.4]); and a prenatal history of hypertension (aOR, 2.5 [1.5-4.4]) and hypoproteinemia (aOR, 5.8 [1.7-20]) are the risks underlying critical obstetric hemorrhage. Prenatal history of hypertension was significantly associated with obstetric disseminated intravascular coagulation (OR, 1.9 [1.5-2.4]); Hemolysis, Elevated Liver enzymes, and Low platelet count (HELLP) syndrome (OR, 3.3 [2.7-4.2]); and eclampsia (OR, 6.1 [4.6-8.1]). In conclusion, a maternal prenatal history of hypertension is associated with the development of HELLP syndrome, eclampsia, and resultant critical hemorrhage. The incidence of HELLP syndrome and eclampsia increased more than fivefold in the presence of prenatal hypertension. However, the likelihood of subsequently developing DIC or experiencing critical bleeding did not change by the presence of prenatal hypertension.

Amniotic fluid embolism causing multiorgan embolisms and reinforces the need for point-of-care ultrasound

INTRODUCTION

Pregnant patients are at risk of several possible complications during the peripartum period. Amniotic fluid embolism (AFE) is a peripartum complication with high mortality and morbidity. The sudden entry of amniotic fluid into the maternal circulation causes a rapid and dramatic sequence of clinical events called AFE. The reported incidence of AFE after a cesarean section is around 19%, and after a normal delivery, it is 11%. AFE causing multiple embolisms is not reported in the literature, nor is the use of point-of-care ultrasound (POCUS) in the diagnosis of AFE. We report a case of AFE causing pulmonary and ovarian embolisms.

CASE

A 34-year-old pregnant lady had an elective lower section cesarean section (LSCS) for transverse lying and placenta previa under combined spinal and epidural anesthesia. She was gravida 3 para 2 and had regular antenatal check-ups, and she presented for her LSCS at 36 weeks of gestation. Immediately after delivery of the fetus, the patient had convulsions, cardiac arrest, and disseminated intravascular coagulopathy (DIC). Immediately, cardiopulmonary resuscitation started, and the team achieved a return of spontaneous circulation (ROSC) in 3 minutes. DIC was corrected with blood and blood products during this maneuver, and POCUS of the inferior vena cava and heart showed multiple small particles floating, thus confirming the diagnosis of AFE in this patient. The patient was transferred to the intensive care unit (ICU), intubated, and ventilated, necessitating a vasopressor infusion. Computed tomographic pulmonary angiography (CTPA) showed pulmonary embolism and ovarian vein embolism, which were managed with heparin infusion. She was hemodynamically stable and weaned from vasopressors, and the ventilator was then extubated on day 13 of ICU admission. She remained awake and in stable condition. The patient was transferred to the ward and subsequently discharged to go home on the 20^th-day post-delivery.

CONCLUSION

AFE can be quickly diagnosed using clinical manifestations and POCUS, and it can be managed early for better patient outcomes. POCUS will show multiple smaller and a few larger amniotic fluid emboli in the heart and vena cava. These larger AFE emboli can migrate and cause multiple embolisms, requiring systemic anticoagulation.

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.

Clinical Presentation and Treatment of Amniotic Fluid Embolism

Obstetric emergencies often require intensive care intervention. Amniotic fluid embolism is a rare, unpredictable, and often catastrophic complication of pregnancy that is suspected in a woman who experiences cardiac arrest after a cesarean section. The condition occurs in approximately 1 in 40 000 births and has an average case-fatality rate of 16%. This complication may result from activation of an inflammatory response to fetal tissue in the maternal circulation. Risk factors may include maternal age over 35 years and conditions in which fluid can exchange between the maternal and fetal circulations. The presentation is abrupt, with profound cardiovascular and respiratory compromise, encephalopathy, fetal distress, and disseminated intravascular coagulopathy. Diagnosis is by exclusion and clinical presentation. Treatment is supportive, with a focus on reversal of hypoxia and hypotension, delivery of the fetus, and correction of coagulopathy. Staff debriefing and psychological support for the woman and family are vital.

Atypical Amniotic Fluid Embolism Managed with a Novel Therapeutic Regimen

Amniotic fluid embolism (AFE) is the second leading cause of maternal mortality in the USA with an incidence of 1 : 15,200 births. The case fatality rate and perinatal mortality associated with AFE are 13–30% and 9–44%, respectively. This rare but devastating complication can be difficult to diagnose as many of the early signs and symptoms are nonspecific. Compounding this diagnostic challenge is a lack of effective treatment regimens which to date are mostly supportive. We present the case of a 26-year-old woman who suffered from suspected AFE and was successfully treated with the novel regimen of Atropine, Ondansetron, and Ketorolac (A-OK). The authors acknowledge that this case does not meet the new criteria proposed, by Clark in 2016, but feel that it is important to share this case report, due to dramatic patient response to the provided supportive therapy presented in this case report. We hope this case report will prompt further research into this novel approach to treating AFE with Atropine, Ondansetron, and Ketorolac.

Amniotic fluid embolism

Amniotic fluid embolism (AFE) is one of the catastrophic complications of pregnancy in which amniotic fluid, fetal cells, hair, or other debris enters into the maternal pulmonary circulation, causing cardiovascular collapse. Etiology largely remains unknown, but may occur in healthy women during labour, during cesarean section, after abnormal vaginal delivery, or during the second trimester of pregnancy. It may also occur up to 48 hours post-delivery. It can also occur during abortion, after abdominal trauma, and during amnio-infusion. The pathophysiology of AFE is not completely understood. Possible historical cause is that any breach of the barrier between maternal blood and amniotic fluid forces the entry of amniotic fluid into the systemic circulation and results in a physical obstruction of the pulmonary circulation. The presenting signs and symptoms of AFE involve many organ systems. Clinical signs and symptoms are acute dyspnea, cough, hypotension, cyanosis, fetal bradycardia, encephalopathy, acute pulmonary hypertension, coagulopathy etc. Besides basic investigations lung scan, serum tryptase levels, serum levels of C3 and C4 complements, zinc coproporphyrin, serum sialyl Tn etc are helpful in establishing the diagnosis. Treatment is mainly supportive, but exchange transfusion, extracorporeal membrane oxygenation, and uterine artery embolization have been tried from time to time. The maternal prognosis after amniotic fluid embolism is very poor though infant survival rate is around 70%.

Amniotic Fluid Embolism: Anaphylactic Reactions With Idiosyncratic Adverse Response

PROBLEM

Amniotic fluid embolism (AFE) is a rare but severe emergency in obstetrics. The aim of the present study was to investigate the pathophysiology of AFE.

METHODS

A search was conducted between 1966 and 2014 through the English-language literature (online MEDLINE PubMed database) using the keyword amniotic fluid embolism combined with anaphylaxis, anaphylactoid, complement activation, mast cells, fetal antigens, and idiosyncratic.

RESULTS

Amniotic fluid embolism is a rare clinical entity but a severe obstetric emergency that can be lethal even in previously healthy women in labor or in the early postpartum period. There appears to be at least 2 mechanisms. First, adverse reactions in AFE are usually unexpected and fetal antigen dose dependent. Given the disastrous entry of amniotic fluid into the maternal circulation, they experience a sudden cardiopulmonary collapse (mechanical obstruction subtype). Second, anaphylactic and anaphylactoid reactions of the remaining AFE are also relatively unexpected and fetal antigen dose independent and can occur at the first exposure to amniotic fluid components. They are associated with complement activation and subsequent postpartum hemorrhage. Cardiac mast cells constitute a central pathogenesis of anaphylactic (immunoglobulin E-dependent) and anaphylactoid (immunoglobulin E-independent) reactions.

CONCLUSIONS

Recent immunologic studies provide a new approach to the study of the pathophysiology of AFE.

An example of prompt and appropriate multidisciplinary management leading to an exceptionally good outcome: a case complicated by amniotic fluid embolism

Amniotic fluid embolism (AFE) is a rare and serious phenomenon; we describe a rare case of AFE occurring after a second trimester surgical termination in a private clinic, which, with prompt transfer and appropriate multidisciplinary management, had an exceptionally good outcome. The patient developed hypotension, respiratory arrest and disseminated intravascular coagulopathy following the procedure but with aggressive management she made a full recovery without any neurological or long-term sequelae.

Out-of-Hospital Perimortem Cesarean Section as Resuscitative Hysterotomy in Maternal Posttraumatic Cardiac Arrest

The optimal treatment of a severe hemodynamic instability from shock to cardiac arrest in late term pregnant women is subject to ongoing studies. However, there is an increasing evidence that early "separation" between the mother and the foetus may increase the restoration of the hemodynamic status and, in the cardiac arrest setting, it may raise the likelihood of a return of spontaneous circulation (ROSC) in the mother. This treatment, called Perimortem Cesarean Section (PMCS), is now termed as Resuscitative Hysterotomy (RH) to better address the issue of an early Cesarean section (C-section). This strategy is in contrast with the traditional treatment of cardiac arrest characterized by the maintenance of cardiopulmonary resuscitation (CPR) maneuvers without any emergent surgical intervention. We report the case of a prehospital perimortem delivery by Caesarean (C) section of a foetus at 36 weeks of gestation after the mother's traumatic cardiac arrest. Despite the negative outcome of the mother, the choice of performing a RH seems to represent up to date the most appropriate intervention to improve the outcome in both mother and foetus.

Academic College of Emergency Experts in India's INDO-US Joint Working Group and OPUS12 Foundation Consensus Statement on Creating A Coordinated, Multi-Disciplinary, Patient-Centered, Global Point-of-Care Biomarker Discovery Network

Biomarker science brings great promise to clinical medicine. This is especially true in the era of technology miniaturization, rapid dissemination of knowledge, and point-of-care (POC) implementation of novel diagnostics. Despite this tremendous progress, the journey from a candidate biomarker to a scientifically validated biomarker continues to be an arduous one. In addition to substantial financial resources, biomarker research requires considerable expertise and a multidisciplinary approach. Investigational designs must also be taken into account, with the randomized controlled trial remaining the “gold standard”. The authors present a condensed overview of biomarker science and associated investigational methods, followed by specific examples from clinical areas where biomarker development and/or implementation resulted in tangible enhancements in patient care. This manuscript also serves as a call to arms for the establishment of a truly global, well-coordinated infrastructure dedicated to biomarker research and development, with focus on delivery of the latest discoveries directly to the patient via point-of-care technology.

Pulmonary Embolic Disorders

Deaths due to pulmonary thromboemboli are frequently encountered by the forensic pathologist and account for a significant percentage of sudden, unexpected deaths. Diagnosing these straightforward cases is often not a challenge, but unfortunately some cases in which a thromboembolism is expected can become complicated. Occasionally, a postmortem clot may mimic a thromboembolism and lead to a mistaken diagnosis, and in other situations it may become paramount to attempt to age a thrombus as part of a medicolegal lawsuit. Additionally, many individuals use the less specific term, “pulmonary emboli”, when referring to these cases in which a portion of a thrombus, usually originating in the deep veins of the lower extremities, breaks off and travels to the pulmonary vasculature bed where it occludes vessels and leads to a rapid demise. One must remember, though, that several other materials and tissues including fat, amniotic fluid, air, tumors, solid organs, synthetic materials, and parasites may be displaced and embolize to the lungs and cause significant disease. In the following pages we will provide a thorough review of pulmonary embolic disorders, focusing on those diseases most likely to be encountered by the forensic pathologist. The aim of this review is to aid the pathologist in using proper terminology, diagnosing various types of embolic disorders, and recognizing potential mimics.