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

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

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 Fetal 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 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.

Amniotic Fluid Embolism (AFE) in China: Are maternal mortality and morbidity preventable?

A case of hospital-patient conflict has occurred in China that has lifted billows in the public and highlighted the lethality of amniotic fluid embolism (AFE). AFE is a rare but severe obstetric complication with high maternal mortality and morbidity. Globally, the incidence of AFE is estimated to be approximately 2 to 6 per 100,000 deliveries. The maternal mortality rate (MMR) attributable to AFE ranges between 0.5 to 1.7 deaths per 100,000 deliveries in the developed world and 1.9 to 5.9 deaths per 100,000 deliveries in the developing world. In developed countries, AFE often accounts for a leading cause of maternal mortality; whereas the proportion of maternal death caused by AFE tends to be not as dominant compared to common perinatal complications in developing countries. With the mechanism remaining to be elucidated, AFE can neither be predicted nor prevented even in developed countries. Treatment requires a set of highly intensive advanced emergency obstetric care, challenging obstetric care in developing countries. Although this complication is currently far from preventable, China has potential to improve the prognosis of AFE by strengthening the emergency obstetric care system.

Survival after an amniotic fluid embolism following the use of sodium bicarbonate

Amniotic fluid embolism (AFE) is a rare and potentially fatal complication of pregnancy. In this case report, we highlight the successful use of sodium bicarbonate in a patient with an AFE. We present a case of a 38-year-old mother admitted for an elective caesarean section. Following the delivery of her baby, the mother suffered a cardiac arrest. Following a protracted resuscitation, transoesophageal echocardiography demonstrated evidence of acute pulmonary hypertension, with an empty left ventricle and an over-distended right ventricle. In view of these findings and no improvement noted from on-going resuscitation, sodium bicarbonate was infused as a pulmonary vasodilator. Almost instantaneous return of spontaneous circulation was noted, with normalisation of cardiac parameters. We propose that in patients suspected with AFE and who have been unresponsive to advance cardiac life support measures, and where right ventricular failure is present with acidosis and/or hypercarbia, the use of sodium bicarbonate should be considered.

Amniotic fluid embolism: an interdisciplinary challenge: epidemiology, diagnosis and treatment

BACKGROUND

Amniotic fluid embolism (AFE) is a life-threatening obstetric complication that arises in 2 to 8 of every 100 000 deliveries. With a mortality of 11% to 44%, it is among the leading direct causes of maternal death. This entity is an interdisciplinary challenge because of its presentation with sudden cardiac arrest without any immediately obvious cause, the lack of specific diagnostic tests, the difficulty of establishing the diagnosis and excluding competing diagnoses, and the complex treatment required, including cardio - pulmonary resuscitation.

METHOD

We selectively reviewed pertinent literature published from 2000 to May 2013 that was retrieved by a PubMed search.

RESULTS

The identified risk factors for AFE are maternal age 35 and above (odds ratio [OR] 1.86), Cesarean section (OR 12.4), placenta previa (OR 10.5), and multiple pregnancy (OR 8.5). AFE is diagnosed on clinical grounds after the exclusion of other causes of acute cardiovascular decompensation during delivery, such as pulmonary thromboembolism or myocardial infarction. Its main clinical features are severe hypotension, arrhythmia, cardiac arrest, pulmonary and neurological manifestations, and profuse bleeding because of disseminated intravascular coagulation and/or hyperfibrinolysis. Its treatment requires immediate, optimal interdisciplinary cooperation. Low-level evidence favors treating women suffering from AFE by securing the airway, adequate oxygenation, circulatory support, and correction of hemostatic disturbances. The sudden, unexplained death of a pregnant woman necessitates a forensic autopsy. The histological or immunohistochemical demonstration of formed amniotic fluid components in the pulmonary bloodflow establishes the diagnosis of AFE.

CONCLUSION

AFE has become more common in recent years, for unclear reasons. Rapid diagnosis and immediate interdisciplinary treatment are essential for a good outcome. Establishing evidence-based recommendations for intervention is an important goal for the near future.

Amniotic fluid embolism: the known and not known

Amniotic fluid embolism was first recognized in 1926, in a Brazilian journal case report, on the basis of large amounts of fetal material in the maternal pulmonary vasculature at autopsy. The first English language description appeared in 1941 and consisted of eight parturients dying suddenly in which, once again, fetal material was seen in the pulmonary vasculature. A control group of 34 pregnant women dying of other recognized causes did not have fetal material in their lungs. The incidence of recognized, serious illness is on the order of two to eight per 100,000, with a mortality rate ranging from 13% to 35%. The diagnosis rests largely on one or more of four clinical signs: circulatory collapse, respiratory distress, coagulopathy, and seizures/ coma. The only confirmatory laboratory test remains autopsy findings although serum tests for fetal antigen, insulin-like growth factor binding protein-1, and complement are currently being investigated. One of the paradoxes of diagnosis is that fetal material in the pulmonary circulation at autopsy is specific for amniotic fluid embolism, while the same finding in the living is not. The mechanism of disease remains uncertain although the best available evidence suggests that complement activation might have a role. In contrast, mast cell degranulation probably is not a mechanism, so amniotic fluid embolism is not an anaphylaxis or anaphylactoid reaction as has been occasionally suggested. Perhaps the greatest unknown is not why 1 in 50,000 pregnant women develop what appears to be an immune response to their fetus, but rather why the other 49,999 do not?

Emergency obstetric simulation training: how do we know where we are going, if we don't know where we have been?

BACKGROUND

Obstetric emergencies contribute significantly to maternal morbidity and mortality. Current training in the management of obstetric emergencies in Australia and internationally focusses on utilising a multidisciplinary simulation-based model. Arguments for and against this type of training exist, using both economic and clinical reasoning.

AIMS

To identify the evidence base for the clinical impact of simulation training in obstetric emergencies and to address some of the concerns regarding appropriate delivery of obstetric emergency training in the Australian setting.

METHODS

A literature search was performed to identify research undertaken in the area of obstetric emergency training. The initial literature search using broad search terms identified 887 articles which were then reviewed and considered for inclusion if they provided original research with a specific emphasis on the impact of training on clinical outcomes.

RESULTS

Ninety-two articles were identified, comprising evidence in the following clinical situations: eclampsia, shoulder dystocia, postpartum haemorrhage, maternal collapse, cord prolapse and teamwork training. Evidence exists for a benefit in knowledge or skills gained from simulation training and for the benefit of training in small units without access to high-fidelity equipment or facilities.

CONCLUSIONS

Evidence exists for a positive impact of training in obstetric emergencies, although the majority of the available evidence applies to evaluation at the level of participants' confidence, knowledge or skills rather than at the level of impact on clinical outcomes. The model of simulation-based training is an appropriate one for the Australian setting and should be further utilised in rural and remote settings.

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.

Current concepts of immunology and diagnosis in amniotic fluid embolism

Amniotic fluid embolism (AFE) is one of the leading causes of maternal mortality and morbidity in developed countries. Current thinking about pathophysiology has shifted away from embolism toward a maternal immune response to the fetus. Two immunologic mechanisms have been studied to date. Anaphylaxis appears to be doubtful while the available evidence supports a role for complement activation. With the mechanism remaining to be elucidated, AFE remains a clinical diagnosis. It is diagnosed based on one or more of four key signs/symptoms: cardiovascular collapse, respiratory distress, coagulopathy, and/or coma/seizures. The only laboratory test that reliably supports the diagnosis is the finding of fetal material in the maternal pulmonary circulation at autopsy. Perhaps the most compelling mystery surrounding AFE is not why one in 20,000 parturients are afflicted, but rather how the vast majority of women can tolerate the foreign antigenic presence of their fetus both within their uterus and circulation?

Successful recovery from delayed amniotic fluid embolism with prolonged cardiac resuscitation

Amniotic fluid embolisms (AFE) are one of the most fatal complications of pregnancy. We describe a case of AFE that occurred 2 h after vaginal delivery at 41 weeks of gestation. The diagnosis of AFE was made by symptoms of dyspnea, coagulopathy, and severe hypotension. ZnCP-1, the characteristic component of meconium, was elevated in the serum. Cardiac compressions after repeated cardiac arrests were required during the initial 2 h of resuscitation. Primary resuscitation was performed with airway management and aggressive fluid management, including infusion of 33 units of red cell concentrates and 57 units of fresh frozen plasma. The patient recovered without any aftereffects. This case report warrants that AFE should be considered when coagulopathy and dyspnea are observed during the postpartum period.