Amniotic fluid embolism rescued using venoarterial extracorporeal membrane oxygenation without initial anticoagulation: A case report and literature review.

RATIONALE: Amniotic fluid embolism (AFE) is a fatal obstetric condition that often rapidly leads to severe respiratory and circulatory failure. It is complicated by obstetric disseminated intravascular coagulation (DIC) with bleeding tendency; therefore, the introduction of venoarterial extracorporeal membrane oxygenation (VA-ECMO) is challenging. We report the case of a patient with AFE requiring massive blood transfusion, rescued using VA-ECMO without initial anticoagulation. PATIENTS CONCERNS: A 39-year-old pregnant patient was admitted with a complaint of abdominal pain. An emergency cesarean section was performed because a sudden decrease in fetal heart rate was detected in addition to DIC with hyperfibrinolysis. Intra- and post-operatively, the patient had a bleeding tendency and required massive blood transfusions. After surgery, the patient developed lethal respiratory and circulatory failure, and VA-ECMO was introduced. DIAGNOSIS: Based on the course of the illness and imaging findings, the patient was diagnosed with AFE. INTERVENTIONS: By controlling the bleeding tendency with a massive transfusion and tranexamic acid administration, using an antithrombotic ECMO circuit, and delaying the initiation of anticoagulation and anti-DIC medication until the bleeding tendency settled, the patient was managed safely on ECMO without complications. OUTCOMES: By day 5, both respiration and circulation were stable, and the patient was weaned off VA-ECMO. Mechanical ventilation was discontinued on day 6. Finally, she was discharged home without sequelae. LESSONS: VA-ECMO may be effective to save the lives of patients who have AFE with lethal circulatory and respiratory failure. For safe management without bleeding complications, it is important to start VA-ECMO without initial anticoagulants and to administer anticoagulants and anti-DIC drugs after the bleeding tendency has resolved.

Current concepts in the use of cell salvage in obstetrics.

PURPOSE OF REVIEW: The worldwide leading cause of maternal death is severe maternal hemorrhage. Maternal hemorrhage can be profound leading to an entire loss of blood volume. In the past two decades, Patient Blood Management has evolved to improve patient's care and safety. In surgeries with increased blood loss exceeding 500 ml, the use of cell salvage is strongly recommended in order to preserve the patient's own blood volume and to minimize the need for allogeneic red blood cell (RBC) transfusion. In this review, recent evidence and controversies of the use of cell salvage in obstetrics are discussed. RECENT FINDINGS: Numerous medical societies as well as national and international guidelines recommend the use of cell salvage during maternal hemorrhage. SUMMARY: Intraoperative cell salvage is a strategy to maintain the patient's own blood volume and decrease the need for allogeneic RBC transfusion. Historically, cell salvage has been avoided in the obstetric population due to concerns of iatrogenic amniotic fluid embolism (AFE) or induction of maternal alloimmunization. However, no definite case of AFE has been reported so far. Cell salvage is strongly recommended and cost-effective in patients with predictably high rates of blood loss and RBC transfusion, such as women with placenta accreta spectrum disorder. However, in order to ensure sufficient practical experience in a multiprofessional obstetric setting, liberal use of cell salvage appears advisable.

Amniotic fluid embolism: 20-year incidence and case-fatality trends in the United States.

OBJECTIVE: To estimate incidence and case-fatality rates of amniotic fluid embolism (AFE) and to examine their temporal trends. STUDY DESIGN: Population-based retrospective cohort study using the 2000-2019 Health Care Cost and Utilization Project, Nationwide Inpatient Sample (HCUP-NIS). Annual population rates were estimated using HCUP-NIS specific weighting. Descriptive analyses and logistic regression described trends within the cohort. RESULTS: Over the study period, AFE incidence rate remained stable (mean 4.9 cases/100,000 deliveries) and the case-fatality rate declined (mean 17.7 %,95 % CI 16.40-10.09). Highest AFE incidence rates and fatality rates were in women ≥ 35 years, African-Americans, and in urban-teaching hospitals. AFE mortality rates decreased among Hispanics. CONCLUSION: AFE rates remained stable and fatality rates declined over time. Highest rates of AFE occurrence and death were in women who typically have greater risk of experiencing adverse obstetrical outcomes. Continued research into early diagnostic methods and effective treatments are needed to further improve AFE incidence and mortality rates.

Amniotic fluid embolism: a reappraisal.

OBJECTIVES: Using cases from our own experience and from the published literature on amniotic fluid embolism (AFE), we seek to improve on existing criteria for diagnosis and discern associated risk factors. Additionally, we propose a novel theory of pathophysiology. METHODS: This retrospective case review includes eight cases of AFE from two hospital systems and 21 from the published literature. All cases were evaluated using the modified criteria for research reporting of AFE by Clark et al. in Am J Obstet Gynecol, 2016;215:408-12 as well as our proposed criteria for diagnosis. Additional clinical and demographic characteristics potentially correlated with a risk of AFE were included and analyzed using descriptive analysis. RESULTS: The incidence of AFE was 2.9 per 100,000 births, with five maternal deaths in 29 cases (17.2 %) in our series. None of the cases met Clark's criteria while all met our criteria. 62.1 % of patients were over the age of 32 years and two out of 29 women (6.9 %) conceived through in-vitro fertilization. 6.5 % of cases were complicated by fetal death. Placenta previa occurred in 13.8 %. 86.2 % of women had cesarean sections of which 52.0 % had no acute maternal indication. CONCLUSIONS: Our criteria identify more patients with AFE than others with a low likelihood of false positives. Clinical and demographic associations in our review are consistent with those previously reported. A possible relationship between cesarean birth and risk of AFE was identified using our criteria. Additionally, we propose a new hypothesis of pathophysiology.

Use of cell salvage at the time of cesarean delivery: a meta-analysis of randomized controlled trials.

OBJECTIVE: Excess blood loss from obstetrical hemorrhage requires transfusion of donor blood, a finite resource. Intraoperative cell salvage collects a patient's own blood that has been lost during cesarean delivery and returns it to their own circulation. We performed a meta-analysis to examine the perioperative outcomes in patients receiving cell salvage at the time of cesarean delivery. DATA SOURCES: Scopus, PubMed, Cochrane Central Register of Controlled Trials, Ovid Medline, and clinicaltrials.gov were searched from database inception through October 2023. STUDY ELIGIBILITY CRITERIA: Eligible studies included randomized controlled trials comparing the use of cell salvage to standard-of-care during cesarean delivery. METHODS: Two authors independently extracted data. Preferred Reporting Items of Systematic Reviews and Meta-Analysis guidelines were used for data extraction and quality assessment. The primary outcomes were the rate of donor blood transfusion and change in hemoglobin level. The secondary outcomes included transfusion reaction, amniotic fluid embolism, and length of hospital stay. Results were summarized as weighted mean difference or risk ratio with associated 95% confidence intervals. Heterogeneity was measured using Higgins I2. RESULTS: A total of 5 randomized controlled trials (n=3361) comparing cell salvage to standard care during cesarean delivery met the inclusion criteria. Primary analysis showed a significant decrease in receiving allogeneic blood transfusion with intraoperative cell salvage use vs standard care (odds ratio, 0.32; 95% confidence interval, 0.23-0.46), with no change in hemoglobin drop (mean difference, -0.77; 95% confidence interval, -1.67 to -0.14). The secondary outcomes showed no difference in transfusion reaction (odds ratio, 0.56; 95% confidence interval, 0.06-5.59), and length of hospital stay (mean difference, -1.90; 95% confidence interval, -4.85 to 1.06). No cases of amniotic fluid embolism were reported among the 1685 patients who received cell salvage. CONCLUSION: Use of cell salvage during cesarean delivery reduced the overall need for allogeneic blood transfusion without increasing the risk of complications, including no cases of amniotic fluid embolism.

Extracorporeal Cardiopulmonary Resuscitation for Amniotic Fluid Embolism: Review and Case Report.

ABSTRACT: Amniotic fluid embolism (AFE) is a rare, sudden, and catastrophic complication of pregnancy that can result in cardiopulmonary arrest, potentially leading to death. The pathophysiology of an AFE includes an inflammatory and coagulopathic response due to fetal materials entering maternal circulation with the hallmark triad of symptoms: acute respiratory distress, cardiovascular collapse, and coagulopathy. Management of AFE should include high-quality cardiopulmonary resuscitation, immediate delivery of the fetus if applicable, early intubation to provide adequate oxygenation and ventilation, fluid volume resuscitation, and ongoing evaluation of coagulopathy. Priorities include thromoboelastography interpretation if available, control of hemorrhage and coagulopathy with blood component therapy, and cardiovascular support through inotropes and vasopressor administration. More recent approaches include implementing the A-OK (atropine, ondansetron, and ketorolac) protocol for suspected AFE protocol, extracorporeal cardiopulmonary resuscitation (ECPR), and extracorporeal membrane oxygenation (ECMO) therapies to increase survival and decrease complications. Venoarterial ECMO is the highest form of life support that provides support in patients with pulmonary and cardiac failure. ECPR is the application of Venoarterial ECMO during cardiopulmonary resuscitation in cases where the cause of arrest is believed to be reversible. Early implementation of ECPR during the acute phase of AFE can provide support for end-organ perfusion in place of the weakened and recovering heart while optimizing oxygenation, making venoarterial ECMO an ideal adjunctive therapy. Because of the rarity of AFE, many obstetrical teams may have limited prior experience in managing these catastrophic cases; however, with ongoing education and simulation, teams can be better prepared in the recognition and management of these life-threatening events.

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

OBJECTIVE: Amniotic fluid embolism is one of the most serious pregnancy complications. It can cause sudden maternal collapse with high mortality and morbidity. We present a case report regarding the important of prompt decision making and multidisciplinary team work for management of amniotic fluid embolism to yield favorable maternal and neonatal outcome. CASE REPORT: This is a 35-year-old, gravida 2, para 1, woman underwent labor induction at gestational age of 37 + 6 weeks due to elective induction. She had sudden facial cyanosis and shortness of breath right after artificial rupture of membrane. Prompt decision of urgent cesarean section, aggressive and timely massive blood transfusion and multidisciplinary team work had spared patient from extracorporeal membrane oxygenation placement and prolonged hospitalization. A male infant was born with Apgar score 3' -> 5' with estimate body weight of 2958 gm; he was hospitalized for 10 days and no other complications was found at follow up pediatric outpatient clinic. CONCLUSION: One of the most dreadful, but rare pregnancy complications is amniotic fluid embolism (AFE). It can cause serious maternal and neonatal morbidity and mortality. Rapid recognition and multidisciplinary team management are essential to maternal and neonatal prognosis.

Amniotic fluid embolism: A comparison of two classification systems in a retrospective 8-year analysis from two tertiary hospitals.

OBJECTIVE: Amniotic fluid embolism (AFE) is a rare life-threatening complication in obstetrics, but the diagnosis lacks a consensual definition. The objective of this study was to compare two different AFE classification systems by analysing the AFE cases from two university hospitals. MATERIAL AND METHODS: In this retrospective study, all patients with a strong suspicion of AFE between 2014 and 2021 at two university hospitals, LMU Women's University Hospital Munich, and Women's University Hospital Basel, were included. Patient records were checked for the ICD-10 code O88.1 (AFE). Diagnoses were confirmed through clinical findings and/or autopsy. The presence of the diagnostic criteria of the Society of Maternal foetal Medicine (SMFM) and the AFE Foundation (AFEF) and of a new framework by Ponzio-Klijanienko et al. from Paris, France, were checked and compared using Chi-square-test. RESULTS: Within our study period, 38,934 women delivered in the two hospitals. Six patients had a strong suspicion of AFE (0.015%). Only three of six patients (50%) presented with all the four diagnostic criteria of the SMFM/AFEF framework. All six patients met the criteria of the modified "Paris AFE framework". CONCLUSION: Using the "Paris AFE framework" based exclusively on clinical criteria can help clinicians to diagnose AFE, anticipate the life-threatening condition of the patient and prepare immediately for best clinical care.

Amniotic fluid embolism-induced cardiopulmonary collapse successfully treated with combination VA-ECMO and Impella CP.

Amniotic fluid embolism (AFE) is a rare but potentially fatal complication of pregnancy. Prompt and aggressive resuscitative strategies are crucial in promoting survivability. We present a case of AFE resulting in cardiopulmonary collapse and subsequent cardiac arrest where we were able to safely deliver the baby and resuscitate the mother with veno-arterial extracorporeal membrane oxygenation and Impella CP-a novel combination known as ECPELLA. We discuss the implications of this approach as a more efficacious strategy in resuscitating AFE-induced cardiogenic shock and arrest.

Unexpected serum phosphorus lost in an amniotic fluid embolism patient.

BACKGROUND: Serum phosphorus concentration reflects body energy equilibrium and functions of the kidney and the coagulation system. It is regulated by serum calcium concentration and parathyroid hormone (PTH). CASE REPORT: We present a case of constant low concentrations of serum phosphorus in a 34-year-old female who was diagnosed with amniotic fluid embolism (AFE) and was continuously treated with extracorporeal membrane oxygenation (ECMO), continuous renal replacement therapy (CRRT) and blood component transfusion during an observational period of 11 days. CONCLUSION: This case highlights that the release of inorganic phosphorus from platelets and plasma into the blood prompts PTH secretion. The administration of active vitamin D supplement and PTH antagonism should be considered to neutralize the negative regulatory effect of PTH on serum phosphorus and to benefit patients' recovery in the intensive care unit.

Association of Pregnancy Characteristics and Maternal Mortality With Amniotic Fluid Embolism.

Importance: Amniotic fluid embolism (AFE) is an uncommon pregnancy complication but is associated with high maternal mortality. Because of the rarity of AFE, associated risks factors and maternal outcomes have been relatively understudied. Objective: To examine the clinical, pregnancy, and delivery characteristics and the maternal outcomes related to AFE in a recent period in the US. Design, Setting, and Participants: This retrospective cohort study examined hospital deliveries from January 1, 2016, to December 31, 2019, from the Healthcare Cost and Utilization Project's National Inpatient Sample. Main Outcomes and Measures: The primary outcome was clinical, pregnancy, and delivery characteristics of AFE, assessed with a multivariable binary logistic regression model. The coprimary outcome was failure to rescue, defined as maternal mortality after AFE. Associations with other severe maternal morbidity indicators and failure to rescue per clinical and pregnancy characteristics were also assessed. Results: A total of 14 684 135 deliveries were examined, with AFE diagnosed in 880 women, corresponding to an incidence rate of 6.0 per 100 000 deliveries. The cohort-level median patient age was 29 years (IQR, 25-33 years). In a multivariable analysis, (1) patient factors of older age, Asian and Black race, Western US region, pregestational hypertension, asthma, illicit substance use, and grand multiparity; (2) pregnancy factors of placental accreta spectrum (PAS), placental abruption, uterine rupture, polyhydramnios, chorioamnionitis, preeclampsia, fetal growth restriction, and fetal demise; and (3) delivery factors of early gestational age, cervical ripening, cesarean delivery, operative delivery, and manual removal were associated with AFE. Among these characteristics, PAS had the largest association with AFE (adjusted odds ratio [aOR], 10.01; 95% CI, 7.03-14.24). When stratified by the PAS subtypes, more severe forms of PAS had a greater association with AFE (aOR for increta and percreta, 17.35; 95% CI, 10.21-28.48; and aOR for accreta, 7.62; 95% CI, 4.83-12.01). Patients who had AFE were more likely to have coagulopathy (aOR, 24.68; 95% CI, 19.38-31.44), cardiac arrest (aOR, 24.56; 95% CI, 17.84-33.81), and adult respiratory distress syndrome (aOR, 10.72; 95% CI, 8.09-14.20). The failure-to-rescue rate after AFE was 17.0% overall. However, the failure-to-rescue rate exceeded 30% when AFE co-occurred with other severe maternal morbidity indicators: 45.8% for AFE, cardiac arrest, and coagulopathy; 43.2% for AFE, shock, and cardiac rhythm conversion; and 38.6% for AFE, cardiac arrest, coagulopathy, and shock. The failure-to-rescue rate after AFE also exceeded 30% when AFE occurred in the setting of placental pathology: 42.9% for AFE and PAS and 31.3% for AFE and placental abruption. Conclusions and Relevance: This contemporaneous, national-level analysis validated previously known risk factors for AFE and confirmed the dismal outcomes of pregnancy complicated by AFE. The association between PAS and AFE, which was not previously reported, warrants further investigation.

Acute ST-Elevation Myocardial Infarction During Labor Due to Amniotic Fluid Embolism.

BACKGROUND Amniotic fluid embolism (AFE) is an extremely rare, life-threatening complication of labor that leads to hyper-acute induction of inflammation and disseminated intravascular coagulation (DIC). Usually, acute pulmonary hypertension results in acute right ventricular failure, while DIC manifests by hemorrhagic and ischemic complications, ultimately leading to multi-organ failure and death. CASE REPORT A 30-year-old primigravida and primipara woman with no prior medical history was admitted for labor after intrauterine fetal death at 37 weeks of gestation. After medical birth induction, she had a convulsive seizure and cardiorespiratory arrest. Short mechanical resuscitation was performed before spontaneous circulation returned. Simultaneously occurring severe vaginal hemorrhage and an ST-elevation myocardial infarction (STEMI) triggered the diagnosis of AFE. Laboratory results fulfilled the criteria for DIC, and hemostatic resuscitation and mechanical hemostasis were performed. Transesophageal echocardiography revealed hypokinesia to akinesia of the inferior wall. Owing to the ongoing DIC, coronary angiography could not be performed. After the patient's transfer to the Intensive Care Unit, ST-segment elevations resolved and the myocardial infarct was managed medically. Cardiac magnetic resonance imaging performed 3 months later demonstrated myocardial scarring in 2 different areas. Referring to the coronary artery anatomy in a computed tomography scan of the chest, the infarcted areas correlated with 2 different coronary supply territories. CONCLUSIONS AFE should be considered in women with acute cardiorespiratory failure during labor. This is the first report of a STEMI triggered by an AFE. The 2 separate areas of infarction, corresponding to the 2 different coronary territories, suggest an AFE-related thrombotic/thromboembolic etiology.

Pulmonary Embolism and Amniotic Fluid Embolism.

Venous thromboembolism (VTE) as well as other embolic events including amniotic fluid embolism (AFE) remain a leading cause of maternal death in the United States and worldwide. The pregnant patient is at a higher risk of developing VTE including pulmonary embolism. In contrast, AFE is a rare, but catastrophic event that remains incompletely understood. Here the authors review the cause of VTE in pregnancy and look at contemporary and evidence-based practices for the evaluation, diagnosis, and management in pregnancy. Then the cause and diagnostic difficulty of AFE as well as what is known regarding the pathogenesis are reviewed.

Amniotic fluid embolism - review and multicentric case analysis.

Amniotic fluid embolism (AFE) is a rare and often fatal obstetric complication, characterized by sudden cardiovascular collapse, dyspnea, seizures, mental alteration or coma and laboratory and clinically dia-gnosed disseminated intravascular coagulation (DIC). Patients reaction is typically biphasic with initial pulmonary hypertension and right ventricular failure, followed by left ventricular failure during or immediately right after labor. Early recognition of AFE is critical to a successful survival. Aggressive shock management is needed in collaboration with an anesthesiologist. Several aspects of the condition remain a controversy. This review critically examines, from the best available evidence, the current knowledge regarding the epidemiology, pathophysiology, dia-gnosis, and available treatment of AFE. This dia-gnosis still determines perinatal morbidity and mortality and potential permanent neurological symptoms for surviving patients.

Acute respiratory distress and amniotic fluid embolism in pregnancy.

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