Amniotic fluid embolism: analysis of the national registry

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.

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.

Amniotic Fluid Embolism in a Grown-Up Congenital Heart Disease Patient

Amniotic fluid embolism (AFE) is a rare but potentially lethal obstetric condition affecting women during labor, delivery, or also in the immediate postpartum period, when amniotic fluid, fetal cells, hair, or other debris could enter the maternal circulation. We present the first case of AFE described in literature in a 33-year-old patient with a complex history of congenital heart disease, where the crucial points for successful course were the prompt recognition and treatment of the disease and the use, for the first time, as diagnostic tool for AFE, of right ventricular free-wall longitudinal speckle-tracking strain.

Top-cited articles in the Journal: a bibliometric analysis

BACKGROUND

The Journal has had a profound influence in nearly 150 years of publishing. A bibliometric analysis, which uses citation analyses to evaluate the impact of articles, can be used to identify the most impactful papers in the Journal's history.

OBJECTIVE

The objective was to identify and characterize the top-cited articles published in the Journal since 1920.

STUDY DESIGN

We used the Web of Science and Scopus databases to identify the most frequently cited articles of the Journal from 1920 through 2018. The top 100 articles from each database were included in our analysis. Articles were evaluated for several characteristics including year of publication, article type, topic, open access, and country of origin. Using the Scopus data, we performed an unadjusted categorical analysis to characterize the articles and a 2 time point analysis to compare articles before and after 1995, the median year of publication from each database list.

RESULTS

The top 100 articles from each database were included in the analysis. This included 120 total articles: 80 articles listed in both and 20 unique in each database. More than half (52%) were observational studies, 9% were RCTs, and 75% were from US authors. When the post-1995 studies were compared with the articles published before 1995, articles were more frequently cited (median 27 vs 13 citations per year, P < .001), more likely to be randomized (14.0% vs 4.8%, P = .009), and more likely to originate from international authors (33.3% vs 17.5%, P = .045).

CONCLUSION

Slightly more than half of the top-cited papers in the Journal since 1920 were observational studies and three quarters of all papers were from US authors. Compared with top-cited papers before 1995, the Journal's top-cited papers after 1995 were more likely to be randomized and to originate from international authors.

Amniotic fluid embolism and spontaneous hepatic rupture during uncomplicated pregnancy: a case report and literature review

Amniotic fluid embolism (AFE) and spontaneous hepatic rupture both are extremely rare complications of pregnancy that can be fatal to mother and/or child. AFE is characterized by a sudden collapse of the cardiovascular system, a change in mental status, and disseminated intravascular coagulation (DIC), occurring immediately during labor, delivery, or postpartum, caused by the inflow of amniotic components into the maternal circulation. Spontaneous hepatic rupture during pregnancy which is most often occurs alongside hypertensive disorders, eclampsia, or HELLP syndrome. We report on the case of a 28-year-old woman (G3P2) who is suffering from AFE and spontaneous hepatic rupture, without history of hypertensive disorders, preeclampsia/eclampsia, or HELLP syndrome, and she died suddenly after delivering of a severe asphyxial neonate within 1 h with postpartum of hepatic rupture and massive hemorrhage. The lack of typical clinical signs and symptoms resulted to the difficulty of early diagnosis. If AFE and hepatic rupture is highly suspected in a pregnant patient, a collaborative multidisciplinary approach is mandatory. Pregnancy women is simultaneously complicated in amniotic fluid embolism and spontaneous hepatic rupture, similar cases are infrequent in the literature, which is reviewed in this report, explore the pathophysiological changes, we hope that can be helpful for the prevention, diagnosis and treatment of similar cases.

Practical use of C1 esterase inhibitor concentrate for clinical amniotic fluid embolism

Amniotic fluid embolism (AFE) causes consumption coagulopathy, which requires a massive transfusion to save the mother's life. The preparation of such a massive transfusion is too time-consuming in extremely emergent clinical settings and occasionally leads to devastating side effects such as transfusion-associated acute lung injury. C1 esterase inhibitor (C1INH) is a protein with the ability to inhibit complement, coagulation and kinin pathways. The C1INH concentration in AFE patients is low, and it has been speculated that the administration of C1INH concentrate could have a striking and beneficial effect on AFE patients in critical condition by ameliorating their perturbed coagulation system. We report the case of a 32-year-old Japanese AFE patient in whom deteriorated vital signs and coagulopathy recovered within minutes after an injection of C1INH concentrate. C1INH concentrate can quickly revive the deteriorated vital signs and the atonic uterus that stem from AFE and may reduce the total amount of transfusion.

Successful extracorporeal cardiopulmonary resuscitation in a postpartum patient with amniotic fluid embolism

Amniotic fluid embolism (AFE) is a rare but fatal obstetric emergency, which is characterized by a sudden cardiovascular collapse, respiratory failure, and disseminated intravascular coagulation (DIC). We report a case of sudden cardiac arrest due to an amniotic-fluid embolism which was successfully treated with veno-arterial extracorporeal membrane oxygenation (ECMO). A 32-year-old female at 39.1 weeks of gestation was scheduled for induction labor. During labor, a sudden generalized tonic-clonic seizure was developed followed by dyspnea and hypotension. An immediate vaginal delivery was performed, and the baby was healthy. Despite the appropriate cardiopulmonary resuscitation, she became hypoxemic and experienced recurrent cardiovascular collapse. ECMO was applied promptly, and the patient became stable rapidly and was discharged without any complications. ECMO seems to be a proper treatment option for catastrophic amniotic-fluid embolism.

Pulmonary embolism caused by ovarian vein thrombosis during cesarean section: a case report

Background

Ovarian vein thrombosis is a rare complication of pregnancy. The representative complaints of patients with ovarian vein thrombosis are abdominal pain and fever. In some cases, however, fatal pulmonary embolism may develop. We report a case of pulmonary embolism presenting with severe hypotension and loss of consciousness during cesarean section possibly caused by ovarian vein thrombosis.

Case presentation

A 25-year-old woman at 38 weeks 4 days of gestation was scheduled for repeat cesarean section. Her past history was unremarkable, and the progress of her pregnancy was uneventful. She did not experience any symptoms indicative of deep vein thrombosis. Cesarean section was performed under spinal anesthesia, and a healthy newborn was delivered. After removal of the placenta, she suddenly developed dyspnea, hypotension, and loss of consciousness with decreased peripheral oxygen saturation. Blood pressure, heart rate, and oxygen saturation recovered after tracheal intubation and mechanical ventilation with oxygen. Postoperative computed tomography revealed no abnormality in the brain or in the pulmonary artery, but a dilated right ovarian vein with thrombi, extending up to the inferior vena cava, was found. A diagnosis of pulmonary embolism caused by ovarian vein thrombosis was made, and heparin was administered. The tracheal tube was removed on the first postoperative day. Her postoperative course was uneventful, and she was discharged with no complications.

Conclusion

Fatal pulmonary embolism might be caused by ovarian vein thrombosis during cesarean section. Careful and continuous observation of the patient after delivery and prompt treatment are important.

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.

Anesthetic management of amniotic fluid embolism -- a multi-center, retrospective, cohort study

INTRODUCTION

Amniotic fluid embolism (AFE) is a rare and potentially lethal obstetric complication, commonly occurring during labor, delivery, or immediately postpartum. There is a paucity of data regarding incidence, risk factors, and clinical management. Our primary objective in this study was to evaluate clinical presentation of AFE and delineate anesthesia management of these cases.

METHODS

This 10 years retrospective multi-center cohort study was performed in five tertiary university-affiliated medical centers, between the years 2005 and 2015. All documented cases of AFE identified according to the ICD guidelines were reviewed manually to determine eligibility for AFE according to Clark's criteria. All cases confirming Clark's diagnosis were included in the cohort.

RESULTS

Throughout the study period, 20 cases of AFE were identified, with an incidence of 4.1 per 100,000 births. Average age at presentation was 35 ± 5 years. Seventy percent of cases presented during vaginal delivery, 20% occurred throughout a cesarean delivery, and 10% occurred during a dilation and evacuation procedure. The most common presenting symptom was sudden loss of consciousness in 12 parturients (66.7%), fetal bradycardia in 11 parturients (55%), and shortness of breath in 10 parturients (50%). Perimortem cesarean section was performed in 55% of cases, although only one case was performed in the delivery suite, while all others were performed in the operating room. Echocardiography was performed in 60% of the cases and all were pathological. Furthermore, 20% of cases were connected to an extracorporeal membrane oxygenation machine. There was a 15% mortality rate of 15%. A further 15% suffered major neurological disability, 25% suffered minor neurological morbidity, and 45% survived without severe complications.

CONCLUSION

AFE is associated with significant maternal morbidity. This study highlights the importance of providing advanced training for the delivery suite staff for cases of maternal cardiovascular collapse secondary to AFE and increasing awareness for this rare and devastating obstetric condition.

Maternal peripartum septic shock caused by intrauterine infection with Edwardsiella tarda: A case report and review of the literature

Edwardsiella tarda (E. tarda) is a rare pathogen in humans, especially during the peripartum period. Only a few cases of fatal neonatal infection with E. tarda have been reported. Herein, we describe a case of maternal septicemia caused by E. tarda following peripartum chorioamnionitis. The mother developed septic shock, disseminated intravascular coagulation and a post-cesarean wound hematoma with abscess. Her condition improved with multidisciplinary therapy including blood transfusion, antimicrobial agents, recombinant thrombomodulin and surgical debridement. E. tarda was isolated from the maternal blood, cesarean wound and neonatal skin, pharynx and gastric fluid. This case demonstrates that peripartum infection with E. tarda is a rare but life-threatening condition, not only for the neonate but also for the mother.

Sudden maternal hypoxemia during elective cesarean section in a woman with placenta previa

There have been no reports regarding imaging‐documented bronchospasm in patients with amniotic fluid embolism (AFE). In a woman with scheduled cesarean section for placenta previa, transient bronchospasm and pulmonary hypertension were documented explaining a sudden drop in SpO₂. Mild AFE was the most likely diagnosis in this patient.

Amniotic fluid embolism mortality rate

AIM

The objective of this study was to determine the mortality rate of amniotic fluid embolism (AFE) using population-based studies and case series.

METHODS

A literature search was conducted using the two key words: 'amniotic fluid embolism (AFE)' AND 'mortality rate'. Thirteen population-based studies were evaluated, as well as 36 case series including at least two patients.

RESULTS

The mortality rate from population-based studies varied from 11% to 44%. When nine population-based studies with over 17 000 000 live births were aggregated, the maternal mortality rate was 20.4%. In contrast, the mortality rate of AFE in case series varies from 0% to 100% with numerous rates in between.

CONCLUSION

The AFE mortality rate in population-based studies varied from 11% to 44% with the best available evidence supporting an overall mortality rate of 20.4%. Data from case series should no longer be used as a basis for describing the lethality of AFE.

Comparison of the Different Definition Criteria for the Diagnosis of Amniotic Fluid Embolism

INTRODUCTION

There are several sets of criteria for the diagnosis of Amniotic Fluid Embolism (AFE), but little is known about their degree of agreement.

AIM

To evaluate the concordance of the Japan criteria for AFE in comparison with two definitions: the US AFE registration entry criteria (the US criteria) and UK Obstetric Surveillance System criteria for defining cases of amniotic fluid embolism (the UK criteria).

MATERIALS AND METHODS

A retrospective observational study was conducted in which the AFE cases registered in the Obstetrical Gynaecological Society of Kinki District in Japan for the period of April 2005 to December 2012 have been analysed by the expert steering obstetric committee, organized by the members of the Obstetric Research group. Cohen's kappa coefficient was used to calculate the agreement among three clinical diagnoses. For inter-group comparison, the Pearson Chi-square test was used (for categorical) and Mann-Whitney test was used (for continuous variables).

RESULTS

Among the 26 cases registered for this period, a total of 18 women were selected as having AFE according to the Japan criteria. Five women died (case fatality rate 27.8%). Agreement between the Japan criteria and the US and UK criteria was k = 0.453 and k = 0.538, respectively, reflecting moderate agreement. However, only 38.9% were given a diagnosis of AFE according to all three criteria. The factor that most often caused disagreement in diagnosis between the Japan criteria and the US criteria was "onset within 30 minutes postpartum". The UK criteria excluded "women with postpartum haemorrhage as the first presenting feature in whom there was no evidence of cardiorespiratory compromise". The case fatality rates in US and UK are higher than in Japan (50.0% and 38.5% vs 27.8%), but this did not result in a significant difference (p=0.497).

CONCLUSION

The groups of subjects identified as having AFE by the Japan criteria had a medium agreement with the US (k=0.453) or UK criteria (k=0.538). These three definition criteria identified different subgroups of patients. Such disagreement has serious implications for research and treatment.

Procoagulant extracellular vesicles in amniotic fluid

Embolization of amniotic fluid (AF) into the blood circulation leads to disseminated intravascular coagulation (DIC). Procoagulant phosphatidylserine (PS)- and tissue factor (TF)-exposing extracellular vesicles (EVs) might play an important role in AF embolism-induced DIC. It was the aim of the present study to perform analyses of the procoagulant properties of AF with a panel of functional coagulation assays and flow cytometry. We applied a prothrombinase assay (that quantifies PS exposure on EVs), an EV-associated TF activity assay, a fibrin generation assay, a thrombin generation assay, a whole blood clotting model, and flow cytometry in AF and control plasma. We found that PS exposure on EVs was 21-fold increased in AF compared with plasma. Also, EV-associated TF activity was highly increased in AF compared with plasma. AF-derived EVs activated the blood coagulation cascade via PS and TF in the fibrin and thrombin generation assays. In a whole blood clotting model, AF-derived EVs significantly shortened the clotting time from 734 ± 139 seconds in the presence to 232 ± 139 seconds in the absence of an anti-TF antibody. The contact activation pathway via factor XII (FXII) was not affected. Applying flow cytometry, a subpopulation of PS⁺ and TF⁺ EVs was identified in AF but not in control plasma. In conclusion, we investigated the effect of AF on blood coagulation and found that PS⁺ and TF⁺ EVs determine their procoagulant potential. Taken together, our data further delineate the pathomechanisms underlying AF-induced coagulopathy.

Neurologic complications in critically ill pregnant patients

Neurologic complications in a critically ill pregnant woman are uncommon but some of the complications (such as eclampsia) are unique to pregnancy and the puerperal period. Other neurologic complications (such as seizures in the setting of epilepsy) may worsen during pregnancy. Clinical signs and symptoms such as seizure, headache, weakness, focal neurologic deficits, and decreased level of consciousness require careful consideration of potential causes to ensure prompt treatment measures are instituted to prevent ongoing neurologic injury. Clinicians should be familiar with syndromes such as pre-eclampsia, eclampsia, stroke, posterior reversible encephalopathy syndrome, and reversible cerebral vasoconstriction syndrome. Necessary imaging studies can usually be performed safely in pregnancy. Scoring systems for predicting maternal mortality are inadequate, as are recommendations for neurorehabilitation. Tensions can arise when there is conflict between the interests of the mother and the interests of the fetus, but in general maternal health is prioritized. The complexity of care requires a multidisciplinary and multiprofessional approach to achieve best outcome in an often unexpected situation.

Risk factors for fatality in amniotic fluid embolism: a systematic review and analysis of a data pool

PURPOSE

Investigating risk factors for amniotic fluid embolism (AFE)-induced fatality.

METHODS

A systematic review of cases of AFE available on PubMed, Scielo, Scopus and AJOL databases that occurred from 1990 to 2015 was carried out. After careful reading of titles, abstracts and full texts, case reports of AFE were reviewed. Risk factors for AFE were considered as independent variables in logistic regression models. The first model was built on the whole data pool. The second model was built on typical cases of AFE, according to the classical triad of symptoms (heart, lungs, coagulopathy). The dependent variable was fatality in both models.

RESULTS

177 cases of AFE were assessed in the first model, while 121 typical cases of AFE were assessed in the second model. Among typical cases of AFE, only oxytocin infusion during labour increases the likelihood of death (odds ratio 2.890, 95% confidence interval 1.166-7.164, p = 0.022). No risk factors for fatality were found in the whole data pool.

CONCLUSIONS

Further research on national registries should focus on the behaviour of oxytocin infusion during labour in AFE cases.

Reproductive decisions after the diagnosis of amniotic fluid embolism

OBJECTIVE

This study aims to describe the subsequent reproductive outcomes in women who either correctly or incorrectly were diagnosed with amniotic fluid embolism (AFE).

STUDY DESIGN

Medical records were obtained, abstracted and reviewed by authors with extensive experience in critical care obstetrics. Telephone interviews of all survivors were conducted to determine obstetrical and contraceptive history. A subgroup underwent further telephone interview to address subsequent reproductive decisions.

RESULTS

By November 2015, 116 medical records of patients diagnosed with AFE were reviewed. Patients who had undergone hysterectomy (n=26), died (n=9), or developed Sheehan's syndrome (n=1) at the time of the original event were excluded from the present analysis. Of the remaining 80 women, 30% (24/80) had subsequently conceived and 32.5% (26/80) patients or their partners had undergone permanent sterilization. At the time of this report, 66% (21/32) of registry participants were categorized to have had AFE and 34% (11/32) as not likely AFE or indeterminate.

CONCLUSIONS

The syndrome of AFE is over-diagnosed. Women diagnosed with AFE who survive conceive another pregnancy less frequently than US women over similar time intervals and often choose a permanent sterilization method, whether or not they actually had AFE, largely out of fear of AFE recurrence.

Amniotic Fluid Embolism with Isolated Coagulopathy: A Report of Two Cases

Amniotic Fluid Embolism (AFE) is a catastrophic complication of pregnancy with high mortality rate. The most common clinical presentation is an abrupt onset of cardiopulmonary collapse. Here, we present an uncommon variant involving isolated disseminated intravascular coagulation that developed without antecedent cardiopulmonary disturbances. Both patients developed symptoms soon after delivery. Blood test was sent at 14 minutes postpartum for the second patient due to suspected amniotic fluid embolism. Fetal components were observed in the uterine veins of the lower uterine segments in both cases. Amniotic fluid embolism with disseminated intravascular coagulopathy typically progresses faster than disseminated intravascular coagulopathy associated with other causes and symptoms. It usually develops within two hours of delivery. Prompt recognition and treatment of this entity is crucial to survival.

Proposed diagnostic criteria for the case definition of amniotic fluid embolism in research studies

Amniotic fluid embolism is a leading cause of maternal mortality in developed countries. Our understanding of risk factors, diagnosis, treatment, and prognosis is hampered by a lack of uniform clinical case definition; neither histologic nor laboratory findings have been identified unique to this condition. Amniotic fluid embolism is often overdiagnosed in critically ill peripartum women, particularly when an element of coagulopathy is involved. Previously proposed case definitions for amniotic fluid embolism are nonspecific, and when viewed through the eyes of individuals with experience in critical care obstetrics, would include women with a number of medical conditions much more common than amniotic fluid embolism. We convened a working group under the auspices of a committee of the Society for Maternal-Fetal Medicine and the Amniotic Fluid Embolism Foundation whose task was to develop uniform diagnostic criteria for the research reporting of amniotic fluid embolism. These criteria rely on the presence of the classic triad of hemodynamic and respiratory compromise accompanied by strictly defined disseminated intravascular coagulopathy. It is anticipated that limiting research reports involving amniotic fluid embolism to women who meet these criteria will enhance the validity of published data and assist in the identification of risk factors, effective treatments, and possibly useful biomarkers for this condition. A registry has been established in conjunction with the Perinatal Research Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development to collect both clinical information and laboratory specimens of women with suspected amniotic fluid embolism in the hopes of identifying unique biomarkers of this condition.

Clinical course of disseminated intravascular coagulopathy-type amniotic fluid embolism: A report of three cases

Amniotic fluid embolism (AFE) is a rare complication of pregnancy and its mortality rate is high. There have been few reports of AFE with presence of severe coagulopathy and incoagulable bleeding, and absence of cardiopulmonary symptoms or limited cardiopulmonary symptoms, followed by massive blood loss during delivery. Such cases have been referred to as disseminated intravascular coagulopathy-type AFE, and the characteristics of this condition have been presented previously. Here we report three cases that fulfilled the diagnostic characteristics of disseminated intravascular coagulopathy-type AFE.

Amniotic Fluid Embolism: Using the Medical Staff Process to Facilitate Streamlined Care

Amniotic fluid embolism (AFE) is a catastrophic consequence of labor and delivery that often results in maternal and neonatal death. These poor outcomes are related largely to the rarity of the event in a population overwhelmingly biased by overall good health. Despite the presence of national AFE registries, there are no published algorithmic approaches to its management, to our knowledge. The purpose of this article is to share a care pathway developed by a multidisciplinary group at a community teaching hospital. Post hoc analysis of a complicated case of AFE resulted in development of this pathway, which addresses many of the major consequences of AFE. We offer this algorithm as a template for use by any institution willing to implement a clinical pathway to treat AFE. It is accompanied by the remarkable case outcome that prompted its development.

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).

Two Obese Patients with Presumptive Diagnosis of Anaphylactoid Syndrome of Pregnancy Presenting at a Community Hospital

Case series

Patient: Female, 21 • Female, 29

Final Diagnosis: Anaphylactoid syndrome of pregnancy

Symptoms: Coagulation dysfunctional

Medication: —

Clinical Procedure: Cardiac intensive care

Specialty: Obstetrics and Gynecology

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.

Amniotic fluid embolism complicating medical termination of pregnancy

BACKGROUND

Amniotic fluid embolism is always a severe complication and generally occurs during labour or immediately after childbirth.

CLINICAL FEATURES

We report the case of a patient falling victim to amniotic fluid embolism after the medical termination of her pregnancy at 24 weeks of amenorrhea following the discovery of a teratoma-carrying foetus. The amniotic fluid embolism diagnosis was strongly suspected in the face of the sudden onset of severe arterial hypotension, hypoxic respiratory distress, a coma state and disseminated intravascular coagulopathy immediately after the delivery. Additional tests were conducted to support the diagnosis: cytological testing of a peripheral venous sample and maternal broncho-alveolar lavage fluid, dosing of tryptase and alpha-fetoprotein levels as well as screening for insulin-like growth factor binding protein 1.

CONCLUSION

Amniotic fluid embolism is a rare and difficult diagnosis, especially in unconventional settings, yet it can be facilitated by screening for amniotic markers and tryptase.

Acute respiratory failure and mechanical ventilation in pregnant patient: A narrative review of literature

Physiological changes of pregnancy imposes higher risk of acute respiratory failure (ARF) with even a slight insult and remains an important cause of maternal and fetal morbidity and mortality. Although pregnant women have different respiratory physiology and different causes of ARF, guidelines specific to ventilatory settings, goals of oxygenation and weaning process could not be framed due to lack of large-scale randomized controlled trials. During the 2009 H1N1 pandemic, pregnant women had higher morbidity and mortality compared to nonpregnant women. During this period, alternative strategies of ventilation such as high-frequency oscillatory ventilation, inhalational of nitric oxide, prone positioning, and extra corporeal membrane oxygenation were increasingly used as a desperate measure to rescue pregnant patients with severe hypoxemia who were not improving with conventional mechanical ventilation. This article highlights the causes of ARF and recent advances in invasive, noninvasive and alternative strategies of ventilation used during pregnancy.