Amniotic fluid embolism

Case report: Maternal cardiac arrest at 12 hours postpartum

Maternal cardiac arrest is a rare occurrence. In this case report, we present a detailed account of a 37-year-old pregnant woman with preeclampsia with severe features who underwent cesarean delivery. The patient experienced dyspnea and hypoxia at 12 hours postpartum, leading to cardiac arrest in the maternity ward. Advanced cardiac life support measures, including 15 minutes of chest compressions, were performed until spontaneous circulation was restored. This study explores the underlying factors contributing to maternal cardiac arrest during the postpartum period. Additionally, it highlights the effective strategies employed by our multidisciplinary team in managing and resolving this critical medical event.

The Anaphylactoid Syndrome of Pregnancy: Two Autopsy Cases

The anaphylactoid syndrome of pregnancy (ASP) is a rare emergency with significant mortality and morbidity, in which the amniotic fluid and fetal cells enter the maternal circulation leading to respiratory failure, altered mental status, hypotension, and disseminated intravascular coagulation. The term ASP was recently introduced to replace the term amniotic fluid embolism since the clinical manifestations of the entity were more similar to a septic or anaphylactic shock rather than that of an embolic event. Two autopsy cases are described, regarding a 35-year-old gravida 2 para 1 and a 34-year-old gravida 1 para 0, where the cause of death was determined to be ASP.

Post-abortion Complications: A Narrative Review for Emergency Clinicians

An abortion is a procedure defined by termination of pregnancy, most commonly performed in the first or second trimester. There are several means of classification, but the most important includes whether the abortion was maternally “safe” (performed in a safe, clean environment with experienced providers and no legal restrictions) or “unsafe” (performed with hazardous materials and techniques, by person without the needed skills, or in an environment where minimal medical standards are not met). Complication rates depend on the procedure type, gestational age, patient comorbidities, clinician experience, and most importantly, whether the abortion is safe or unsafe. Safe abortions have significantly lower complication rates compared to unsafe abortions. Complications include bleeding, retained products of conception, retained cervical dilator, uterine perforation, amniotic fluid embolism, misoprostol toxicity, and endometritis. Mortality rates for safe abortions are less than 0.2%, compared to unsafe abortion rates that range between 4.7-13.2%. History and physical examination are integral components in recognizing complications of safe and unsafe abortions, with management dependent upon the diagnosis. This narrative review provides a focused overview of post-abortion complications for emergency clinicians.

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.

Shock in China 2018 (SIC-study): a cross-sectional survey

Background

Shock is a critical illness that seriously threatens the lives of patients. This study explains the epidemiology of shock, mortality of shock, and identify factors that related to hospital death.

Methods

This is a multi-centre cross-sectional survey, which included 1,064 tertiary hospitals in 31 provinces, municipalities, and autonomous regions across China mainland. Totally 289,428 patients who diagnosed with shock based on the ICD-10 abstracted from the Hospital Quality Monitoring System (HQMS) in 2018, a national database administrated by National Health Commission of the PRC.

Results

Patients diagnosed with shock were screened and classified according to the type of shock. Regression analysis was used to identify factors that related to death. A total of 79,668,156 medical records were included in HQMS in 2018, from which a total of 289,428 records with shock were identified. Hypovolemic shock occurred in 128,436 cases (44.38%), septic shock occurred in 121,543 cases (41.99%), cardiogenic shock occurred in 44,597 cases (15.41), and obstructive shock occurred in 3,168 cases (1.09%). Of these, 8,147 cases (2.81%) had mixed shock, which means had two or more types of shock. For all the shock cases, the top three frequent concomitant diseases recorded were circulatory system diseases (55.22%), digestive system diseases (53.64%), and respiratory system diseases (53.31%). Of the four types of shock, cases with cardiogenic shock had the highest in-hospital mortality (31.6%), followed by those with obstructive shock (25.2%), septic shock (22.9%), and hypovolemic shock (15.5%). Interestingly, the combination of shock and malignant tumors is one of the major factors that related to hospital deaths.

Conclusions

Shock is a serious disease with a high fatality rate and huge clinical costs. According to this epidemiological survey of shock in China 2018, we should clarify the factors related to the hospital death in shock cases.

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.

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.

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.

Anaphylactoid Syndrome of Pregnancy

Anaphylactoid syndrome of pregnancy (ASP) is a widespread, proinflammatory, anaphylactic-like reaction that can occur when amniotic fluid enters the maternal blood circulation. ASP is characterized by four cardinal findings: respiratory distress, altered mental status, hypotension, and disseminated intravascular coagulation. ASP is commonly associated with maternal and neonatal mortality. Early recognition followed by prompt and aggressive treatment can improve survival rates and are among the most critical activities for nurses and other clinicians caring for women with ASP.

Amniotic Fluid Embolism. Is a New Pregnancy Possible? Case Report

Amniotic fluid embolism (AFE) is a rare but potentially catastrophic clinical condition, characterized by a combination of signs and symptoms that reflect respiratory distress, cardiovascular collapse and disseminated intravascular coagulation (DIC). Its pathogenesis is still unclear. More recently, the traditional view of obstruction of pulmonary capillary vessels by amniotic fluid emboli as the main explanation for the etiology has been ruled out, and immunologic factors and the activation of the inflammatory cascade took on an important role. Amniotic fluid embolism has an unpredictable character, its diagnosis is exclusively clinical, and the treatment consists mainly of cardiovascular support and administration of blood products to correct the DIC. No diagnostic test is recommended until now, though multiple blood markers are currently being studied. The authors present a case report of a woman who had survived AFE in her previous pregnancy and had a subsequent pregnancy without recurrence, providing one more clinical testimony of the low risks for the pregnancy after AFE.

Diagnosis of Acute Neurologic Emergencies in Pregnant and Postpartum Women

Acute neurologic symptoms in pregnant and postpartum women may be caused by exacerbation of a preexisting neurologic condition, the initial presentation of a non-pregnancy-related problem, or a new neurologic problem. Pregnant and postpartum patients with headache and neurologic symptoms are often diagnosed with preeclampsia or eclampsia; however, other etiologies must also be considered. A team approach with close communication between emergency physicians, neurologists, maternal-fetal medicine specialists, and radiologists is the key to obtaining best outcomes. This article reviews the clinical features and differential diagnosis of acute serious neurologic conditions in pregnancy and the puerperium, focusing on diagnosis.

Amniotic fluid embolism: diagnosis and management

OBJECTIVE

We sought to provide evidence-based guidelines regarding the diagnosis and management of amniotic fluid embolism.

STUDY DESIGN

A systematic literature review was performed using MEDLINE, PubMed, EMBASE, and the Cochrane Library. The search was restricted to English-language articles published from 1966 through March 2015. Priority was given to articles reporting original research, in particular randomized controlled trials, although review articles and commentaries were consulted. Abstracts of research presented at symposia and scientific conferences were not considered adequate for inclusion. Evidence reports and published guidelines were also reviewed, and additional studies were located by reviewing bibliographies of identified articles. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was used for defining the strength of recommendations and rating quality of the evidence. Consistent with US Preventive Task Force guidelines, references were evaluated for quality based on the highest level of evidence.

RESULTS AND RECOMMENDATIONS

We recommend the following: (1) we recommend consideration of amniotic fluid embolism in the differential diagnosis of sudden cardiorespiratory collapse in the laboring or recently delivered woman (GRADE 1C); (2) we do not recommend the use of any specific diagnostic laboratory test to either confirm or refute the diagnosis of amniotic fluid embolism; at the present time, amniotic fluid embolism remains a clinical diagnosis (GRADE 1C); (3) we recommend the provision of immediate high-quality cardiopulmonary resuscitation with standard basic cardiac life support and advanced cardiac life support protocols in patients who develop cardiac arrest associated with amniotic fluid embolism (GRADE 1C); (4) we recommend that a multidisciplinary team including anesthesia, respiratory therapy, critical care, and maternal-fetal medicine should be involved in the ongoing care of women with AFE (Best Practice); (5) following cardiac arrest with amniotic fluid embolism, we recommend immediate delivery in the presence of a fetus ≥23 weeks of gestation (GRADE 2C); (6) we recommend the provision of adequate oxygenation and ventilation and, when indicated by hemodynamic status, the use of vasopressors and inotropic agents in the initial management of amniotic fluid embolism. Excessive fluid administration should be avoided (GRADE 1C); and (7) because coagulopathy may follow cardiovascular collapse with amniotic fluid embolism, we recommend the early assessment of clotting status and early aggressive management of clinical bleeding with standard massive transfusion protocols (GRADE 1C).

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%.

Decompensated Heart Failure in Pregnancy

Heart disease is a common cause of morbidity and mortality during pregnancy. Symptoms and signs of heart failure in a pregnant woman are an indication for urgent assessment to establish a diagnosis and appropriate management. This is best accomplished through a multidisciplinary approach in which both cardiologists and obstetricians need to participate in order to provide expert counselling and care in pursuit of safe motherhood. Congenital heart disease, although common, once corrected is an unusual source of complications, which are more likely to develop as a consequence of ventricular failure, pulmonary hypertension and aortic arch disease. Rheumatic valvular heart disease is a challenge because of the need for anticoagulation during pregnancy and the risk of sepsis associated with childbirth. This review outlines a contemporary approach to heart failure presenting during pregnancy.

Incidence, diagnosis and pathophysiology of amniotic fluid embolism

Amniotic fluid embolism (AFE) is a rare clinical entity, sometimes fatal. A review was conducted to describe the frequency, diagnosis and pathophysiology of AFE. The reported incidences ranged from 1.9 cases per 100,000 maternities (UK) to 6.1 per 100,000 maternities (Australia), which can vary considerably, depending on the period, region of study and the definition. Although the development of amniotic fluid-specific markers would have an impact on early diagnosis, definition of AFE based on these markers is not widely accepted. To date, immunological mechanisms, amniotic fluid-dependent anaphylactic reaction and complement activation, have been proposed as potential pathogenetic and pathophysiological mechanisms. Immune cell activation induced through complement activation may be associated with the mechanism that immediately initiates maternal death, only in susceptible individuals. This review will focus on advances in the field of AFE biology and discuss the prevalence, diagnosis and pathophysiology of AFE.

Amniotic fluid embolism

Amniotic fluid embolism (AFE) is an unpredictable and as-of-yet unpreventable complication of maternity. With its low incidence it is unlikely that any given practitioner will be confronted with a case of AFE. However, this rare occurrence carries a high probability of serious sequelae including cardiac arrest, ARDS, coagulopathy with massive hemorrhage, encephalopathy, seizures, and both maternal and infant mortality. In this review the current state of medical knowledge about AFE is outlined including its incidence, risk factors, diagnosis, pathophysiology, and clinical manifestations. Special attention is paid to the modern aggressive supportive care that resulted in an overall reduction in the still alarmingly high mortality rate of this devastating entity. The key factors for successful management and resolution of this disease process continue to be sharp vigilance, a high level of clinical suspicion, and rapid all-out resuscitative efforts on the part of all clinicians involved in the medical care of the parturient.

[Amniotic fluid embolism: report of the successful outcome of a case with inaugural cardiac arrest and early DIVC complicated by hemoperitoneum of iatrogen origin and bleeding of an hepatic adenoma]

Amniotic fluid embolism is a relatively rare clinical entity and with difficult medical recognition. However, it is the second leading cause of maternal mortality. We report here the case of a 32-year-old patient who underwent elective caesarean section complicated by an amniotic fluid embolism with cardiac arrest. The presence of a major disseminated intravascular coagulation favored the occurrence of a retroperitoneal hematoma of iatrogenic origin on attempt of femoral venous catheterization and that of hemoperitoneum on bleeding of an hepatic adenoma. The diagnostic of amniotic fluid embolism was confirmed by the presence of amniotic cells in the bronchoalveolar lavage. The patient survived without sequelae.

Pulmonary hypertension in pregnancy: critical care management

Pulmonary hypertension is common in critical care settings and in presence of right ventricular failure is challenging to manage. Pulmonary hypertension in pregnant patients carries a high mortality rates between 30-56%. In the past decade, new treatments for pulmonary hypertension have emerged. Their application in pregnant women with pulmonary hypertension may hold promise in reducing morbidity and mortality. Signs and symptoms of pulmonary hypertension are nonspecific in pregnant women. Imaging workup may have undesirable radiation exposure. Pulmonary artery catheter remains the gold standard for diagnosing pulmonary hypertension, although its use in the intensive care unit for other conditions has slowly fallen out of favor. Goal-directed bedside echocardiogram and lung ultrasonography provide attractive alternatives. Basic principles of managing pulmonary hypertension with right ventricular failure are maintaining right ventricular function and reducing pulmonary vascular resistance. Fluid resuscitation and various vasopressors are used with caution. Pulmonary-hypertension-targeted therapies have been utilized in pregnant women with understanding of their safety profile. Mainstay therapy for pulmonary embolism is anticoagulation, and the treatment for amniotic fluid embolism remains supportive care. Multidisciplinary team approach is crucial to achieving successful outcomes in these difficult cases.

Peripartum acute coronary syndrome in an otherwise healthy patient

Myocardial ischemia in pregnancy poses a significant challenge for the anesthesiologist. It is a relatively rare disorder (approximately 180 cases published in the indexed literature since 1922) but it carries high mortality. Diagnosis is frequently hampered by diminished sensitivity of several testing modalities conventionally used to diagnose myocardial ischemia. The etiology of cardiac ischemia also is multifactorial and occurs during a very dynamic period. A case of acute coronary syndrome in a parturient during urgent cesarean delivery for placental abruption is presented, followed by a brief review of the topic.

Critical care management of obstetric emergencies

Obstetric cases are normally well managed on the labour suite. However, emergencies are not uncommon, and when they occur, they can be major. It is vital that rapid assessment and management are put in place. Critical care doctors are often called upon to do so.

Surgical treatment of an amniotic fluid embolism with cardiopulmonary collapse

Amniotic fluid embolism is a rare but devastating condition associated with a very high rate of morbidity and mortality. The treatment has traditionally been aggressive supportive care. We report a case of a term pregnant woman with complete cardiovascular collapse secondary to a paradoxical amniotic fluid embolism. The embolism was seen on transesophageal echocardiogram during an emergency Cesarean section as a free-floating interatrial clot through a patent foramen ovale. She was subsequently and successfully treated with immediate cardiopulmonary bypass, thromboembolectomy, and closure of the patent foramen ovale.

Amniotic fluid embolism-apropos two consecutive cases

Amniotic fluid embolism (AFE) is a sporadic, unpredictable, and usual fatal obstetric complication. The paper deals with two cases of maternal deaths because of AFE verified by medicolegal autopsy. In both the cases, several known risk factors associated with AFE, such as increased maternal age (41 and 35 years), diabetes, augmented labor, and cesarean delivery, were identified. Clinical features were typical, including sudden onset of cardiovascular and respiratory symptoms. In the patient who survived longer, both clinical and autopsy signs of disseminated intravascular coagulopathy were present, while they were absent in the case where death occurred rapidly. This paper describes briefly the particular features to look for at autopsy and stresses the importance of histology examination and staining techniques.

Chest computed tomography of a patient revealing severe hypoxia due to amniotic fluid embolism: a case report

Introduction

Amniotic fluid embolism is one of the most severe complications in the peripartum period. Because its onset is abrupt and fulminant, it is unlikely that there will be time to examine the condition using thoracic computed tomography (CT). We report a case of life-threatening amniotic fluid embolism, where chest CT in the acute phase was obtained.

Case presentation

A 22-year-old Asian Japanese primiparous woman was suspected of having an amniotic fluid embolism. After a Cesarean section for cephalopelvic disproportion, her respiratory condition deteriorated. Her chest CT images were examined. CT findings revealed diffuse homogeneous ground-glass shadow in her bilateral peripheral lung fields. She was therefore transferred to our hospital. On admission to our hospital's intensive care unit, she was found to have severe hypoxemia, with SpO₂ of 50% with a reservoir mask of 15 L/min oxygen. She was intubated with the support of noninvasive positive pressure ventilation. She was successfully extubated on the sixth day, and discharged from the hospital on the twentieth day.

Conclusion

This is the first case report describing amniotic fluid embolism in which CT revealed an acute respiratory distress syndrome-like shadow.

Amniotic fluid embolism: an evidence-based review

We conducted an evidence-based review of information about [corrected] amniotic fluid embolism (AFE). The estimated incidence of AFE is 1:15,200 and 1:53,800 deliveries in North America and Europe, respectively. The case fatality rate and perinatal mortality associated with AFE are 13-30% and 9-44%, respectively. Risk factors associated with an [corrected] increased risk of AFE include advanced maternal age, placental abnormalities, operative deliveries, eclampsia, polyhydramnios, cervical lacerations, [corrected] and uterine rupture. The hemodynamic response in [corrected] AFE is biphasic, with initial pulmonary hypertension and right ventricular failure, followed by left ventricular failure. Promising therapies include selective pulmonary vasodilators and recombinant activated factor VIIa. Important topics for future research are presented.

Responding to amniotic fluid embolism

Amniotic fluid embolism (AFE), an uncommon disorder with a high fatality rate, is an obstetric emergency that requires swift recognition and intervention to save both the mother's life and that of her child.The high mortality rate and varying theories as to its cause make it difficult to diagnose AFE, which can occur at any point during labor and delivery, including during cesarean birth. These factors make it important for perioperative nurses to understand and recognize AFE when it occurs in the OR. Rapid delivery of the fetus is imperative for the survival of both mother and child. Monitoring and aggressively providing respiratory and circulatory support interventions are required if the mother is to survive AFE.

Amniotic fluid embolism

The disastrous entry of amniotic fluid into the maternal circulation leads to dramatic sequelae of clinical events, characteristically referred to as Amniotic fluid embolism (AFE). The underlying mechanism for AFE is still poorly understood. Unfortunately, this situation has very grave maternal and fetal consequences. AFE can occur during labor, caesarean section, dilatation and evacuation or in the immediate postpartum period. The pathophysiology is believed to be immune mediated which affects the respiratory, cardiovascular, neurological and hematological systems. Undetected and untreated it culminates into fulminant pulmonary edema, intractable convulsions, disseminated intravascular coagulation (DIC), malignant arrhythmias and cardiac arrest. Definite diagnosis can be confirmed by identification of lanugo, fetal hair and fetal squamous cells (squames) in blood aspirated from the right ventricle. Usually the diagnosis is made clinically and by exclusion of other causes. The cornerstone of management is a multidisciplinary approach with supportive treatment of failing organs systems. Despite improved modalities for diagnosing AFE, and better intensive care support facilities, the mortality is still high.

Obstetric disorders in the ICU

Obstetric disorders account for 55% to 80% of admissions to the intensive care unit in the obstetric population. Medical conditions are emerging as the leading cause of maternal mortality, partly because of marked improvement in surgical and obstetric care in the developed world. The rise in maternal mortality related to medical conditions can be explained by multiple factors: improved medical care, women with chronic illnesses reaching childbearing years, older age at time of first pregnancy, improved reproductive technologies, and severe medical conditions exacerbated by the physiologic changes of pregnancy. This article reviews obstetric disorders leading to intensive care unit admissions.

Complement C3a expression and tryptase degranulation as promising histopathological tests for diagnosing fatal amniotic fluid embolism

To date, the most recent specific diagnostic investigations for amniotic fluid embolism have been unable to conclusively identify any mechanism of disease other than a physical block to the circulation. We selected eight fatal cases in previously healthy women with uneventful singleton term pregnancies who presented to tertiary care centers in Italy for delivery. Pathologic features were assessed immunohistochemically using anti-fibrinogen, anti-tryptase, anti-C(3a), and anti-cytokeratin antibodies. AE1/AE3 cytokeratin stains proved positive, and tryptase-positive material was documented outside pulmonary mast cells. In all studied cases, expression of complement C(3a) was twofold lower than in the control group, suggesting a possible complement activation in AFE, initiated by fetal antigen leaking into the maternal circulation.

Endothelial pathomechanisms in acute lung injury

Acute lung injury (ALI) and its most severe extreme the acute respiratory distress syndrome (ARDS) refer to increased-permeability pulmonary edema caused by a variety of pulmonary or systemic insults. ALI and in particular ARDS, are usually accompanied by refractory hypoxemia and the need for mechanical ventilation. In most cases, an exaggerated inflammatory and pro-thrombotic reaction to an initial stimulus, such as systemic infection, elicits disruption of the alveolo-capillary membrane and vascular fluid leak. The pulmonary endothelium is a major metabolic organ promoting adequate pulmonary and systemic vascular homeostasis, and a main target of circulating cells and humoral mediators under injury; pulmonary endothelium is therefore critically involved in the pathogenesis of ALI. In this review we will discuss mechanisms of pulmonary endothelial dysfunction and edema generation in the lung with special emphasis on the interplay between the endothelium, the immune and hemostatic systems, and highlight how these principles apply in the context of defined disorders and specific insults implicated in ALI pathogenesis.

Incidence and risk factors of amniotic fluid embolisms: a population-based study on 3 million births in the United States

OBJECTIVE

Amniotic fluid embolism (AFE) is a condition occurring during delivery that can lead to severe maternal morbidity and mortality. Given the rarity of its occurrence, current estimates and predictors of the incidence and outcomes are often difficult to obtain.

STUDY DESIGN

We conducted a population-based cohort study on 3 million birth records in the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample from 1999 to 2003 to estimate the incidence and case fatality of AFEs. Logistic regression was used to calculate the odds ratio (OR) and corresponding 95% confidence intervals (CIs) of demographic and obstetrical determinants of AFEs and fatal AFEs.

RESULTS

The overall incidence of AFE was 7.7 per 100,000 births (95% CI 6.7 to 8.7), with a case fatality rate of 21.6% (95% CI 15.5 to 27.6%). AFE was associated with maternal age greater than 35 (OR 2.2, 95% CI 1.5 to 2.1), placenta previa (OR 30.4, 95% CI 15.4 to 60.1), and cesarean delivery (OR 5.7, 95% CI 3.7 to 8.7). Although AFEs were not significantly associated with induction of labor (OR 1.5, 95% CI 0.9 to 2.3), they were associated with preeclampsia, abruptio placentae, and the use of forceps. Among women with an AFE, common demographic or obstetrical determinants were not predictive of maternal mortality.

CONCLUSION

AFE is a rare but serious condition that is associated with advanced maternal age, placental pathologies, and cesarean deliveries. Further research on the treatment of this condition is necessary.