Case 33-2019: A 35-Year-Old Woman with Cardiopulmonary Arrest during Cesarean Section

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.

Early treatment with Fibrinogen γ-chain peptide-coated, ADP-encapsulated Liposomes (H12-(ADP)-liposomes) ameliorates post-partum hemorrhage with coagulopathy caused by amniotic fluid embolism in rabbits

BACKGROUND

Amniotic fluid embolism is an unpredictable and sometimes lethal complication of childbirth. Fibrinogen γ-chain peptide-coated, ADP-encapsulated Liposomes (H12-(ADP)-liposomes), which were developed as a platelet substitute, may be useful to control postpartum hemorrhage with consumptive coagulopathy.

OBJECTIVE

This study aimed to establish a hemodynamically stable amniotic fluid embolism animal model and evaluate the efficacy of H12-ADP-liposome infusion in the initial management of postpartum hemorrhage complicated with amniotic fluid embolism-involved coagulopathy.

STUDY DESIGN

Pregnant New Zealand white rabbits (28th day of pregnancy or normal gestation period of 29-35 days) underwent cesarean delivery, followed by intravenous administration of amniotic fluid (a total of 3.0 mL administered in 4 doses over 9 minutes). Thereafter, uncontrolled postpartum hemorrhage was induced by transecting the right midartery and concomitant vein in the myometrium. After initial bleeding for 5 minutes, rabbits received isovolemic fluid resuscitation through the femoral vein with an equivalent volume of blood loss every 5 minutes for 60 minutes. The transfusion regimens included platelet-rich plasma, platelet-poor plasma, and a bolus administration of H12-ADP-liposomes followed by platelet-poor plasma transfusion (8 rabbits per group). Moreover, 60 minutes after initiation of bleeding, rabbits received surgical hemostasis by ligation of bleeding vessels, except in cases with spontaneous hemostasis.

RESULTS

The administration of amniotic fluid caused thrombocytopenia (56±3 × 103/μL) and prolonged both clotting time (before administration: 130.0±3.0 to 171.0±5.0 seconds) and prothrombin time (4.5±0.1 to 4.7±0.1 seconds). After the initial 5-minute bleeding in the rabbits, the mean arterial pressure fell to 43±2 mm Hg. Platelet-poor plasma transfusion alone further prolonged clotting time and prothrombin time at 60 minutes (192.0±10.0 and 5.2±0.1 seconds, respectively) with decreasing mean arterial pressure to <40 mm Hg. By contrast, the administration of H12-ADP-liposomes followed by platelet-poor plasma transfusion reduced the prolonged clotting time (153.0±5.0 seconds) and prothrombin time (4.9±0.1 seconds) similar to platelet-rich plasma transfusion (154.0±11.0 and 4.9±0.1 seconds, respectively) at 60 minutes. These rabbits maintained a mean arterial pressure of >45 mm Hg throughout the experiment. H12-ADP-liposome infusion and platelet-poor plasma transfusion and platelet-rich plasma transfusion yielded spontaneous hemostasis in 4 of 8 rabbits, whereas platelet-poor plasma transfusion did not stop bleeding in any of the rabbits. The total blood loss was 59±17 mL in the H12-ADP-liposomes and platelet-poor plasma group, which was half of that in the platelet-poor plasma group (124±10 mL).

CONCLUSION

H12-ADP-liposome infusion may be effective in the initial management of postpartum hemorrhage complicated with amniotic fluid embolism, resulting in mitigation of consumptive coagulopathy.

Echocardiography findings in amniotic fluid embolism: a systematic review of the literature

PURPOSE

Amniotic fluid embolism (AFE) is a leading cause of obstetrical cardiac arrest and maternal morbidity. The pathogenesis of hemodynamic collapse is thought to be from right ventricular (RV) failure; however, there is a paucity of data documenting echocardiography findings in this population. We undertook a systematic review of the literature to evaluate the echocardiography findings in patients with AFE.

SOURCES

We retrieved all case reports and case series reporting AFE in Embase and MEDLINE from inception to 20 November 2021. Studies reporting AFE diagnosed by fulfilling at least one of three different proposed AFE criteria and echocardiography findings during hospitalization were included. Patient and echocardiographic data were retrieved, and univariate logistic regression analysis was performed for outcomes of interest. Bias was assessed using the Joanna Briggs Institute clinical appraisal tool for case series.

PRINCIPAL FINDINGS

Eighty publications reporting on 84 patients were included in the final review. Fifty-five out of 82 patients with data (67%) showed RV dysfunction, including 11/82 (13%) with biventricular dysfunction; 14/82 (17%) had normal systolic function. No data on RV or left ventricular function were reported for two patients. The presence of RV dysfunction on echocardiography was associated with cardiac arrest (odds ratio [OR], 3.66; 95% confidence interval [CI], 1.39 to 9.67; P = 0.009), and a composite risk of cardiac arrest, maternal death or use of extracorporeal membrane oxygenation (OR, 3.86; 95% CI, 1.43 to 10.4; P = 0.007). A low risk of bias was observed in 15/84 (18%) cases.

CONCLUSIONS

Right ventricular dysfunction on echocardiography is a common finding in AFE and is associated with a high risk of cardiac arrest. The finding of RV dysfunction on echocardiography may help diagnose AFE and help triage the highest risk patients with AFE.

STUDY REGISTRATION

PROSPERO (CRD42021271323); registered 1 September 2021.

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.

Successful ECMO-assisted open chest cardiopulmonary resuscitation in a postpartum patient with delayed amniotic fluid embolism

Background

Amniotic fluid embolism (AFE) is a rare but potentially dangerous severe obstetrics complication, which is accompanied by an incidence between 1.9 and 6.1 per 100,000 births.

Case presentation

Here, we report an AFE case after cesarean delivery diagnosed on a cardiac arrest complicated by acute respiratory distress syndrome and coagulopathy. Diagnosis, risk factors and pathophysiology for AFE have been fully discussed, besides, extracorporeal membrane oxygenation in the early management of cardiac arrest was used, describing the indication, efficacy and successful performed of open-chest cardiopulmonary resuscitation for the patient.

Conclusion

In AFE with cute cardiovascular collapse, extracorporeal membrane oxygenation support can be considered as the alternative therapies.

The rare but dangerous amniotic fluid embolish after cesarean delivery was diagnosed.

A cardiac arrest accompanied by acute respiratory distress syndrome and coagulopathy was recorded.

Diagnosis, risk factors and pathophysiology for amniotic fluid embolish in this case were detailly discussed.

Cardiac Arrest during Cesarean Section - A Case Report and Review of the Differential Diagnosis

AIM

According to the World Health Organization, approximately 810 pregnant women die every day as a consequence of peripartum complications. A large proportion of deaths happen in developing countries. Peripartum cardiac arrest is a rare event that must be treated immediately. It is important to consider the differential diagnoses in order to save lives.

METHODS

In this review, we discuss a differential diagnosis of cardiac arrest according to the BEAU-CHOPS scheme of the American Heart Association in the relation to the case report of our 40-year-old G5/P3 patient who went into cardiac arrest during cesarean delivery.

RESULTS

Typical differentials for cardiac arrest during labor are bleeding, embolism, anesthetic complications, cardiovascular diseases, eclampsia, and sepsis. All of them were considered and ruled out in this patient. In the end, we suspect that physiological cardio-inhibitory reflexes triggered by sudden profound hypovolemia after placental separation along with the patient's risk factors, especially obesity and maternal age, and the administration of spinal anesthesia all potentially contributed to the cardiac arrest.

CONCLUSIONS

This review highlights that the cardiac arrest during labor can be triggered by the multifactorial etiology, but firstly the typical differential diagnosis needs to be excluded.

Amniotic fluid embolism: lessons for rapid recognition and intervention

Amniotic fluid embolism is a rare, often fatal complication of labor and delivery. The classic presentation is the sudden onset of a triad of clinical manifestations: hypoxia, hypotension and coagulopathy. Understanding of the syndrome as an immunologically mediated, complicated and often catastrophic maternal response to fetal or placental antigens is coming into focus. New treatments such as extracorporeal membrane oxygenation (ECMO) and better use of old treatments such as transfusion offer hope, but the condition is often rapidly fatal, so saving the maternal and fetal lives depends on rapid recognition of the syndrome. This series of three cases illustrates the clinical features enabling the rapid recognition needed for successful treatment of amniotic fluid embolism syndrome.

Amniotic Fluid Embolism Treated With Inhaled Milrinone: A Case Report

We present a patient with sudden cardiovascular collapse during cesarean delivery that was attributed to amniotic fluid embolism (AFE). The syndrome of AFE may be initiated by an anaphylactoid response to amniotic fluid in the maternal circulation that triggers the release of pulmonary vasoconstrictors, with transient pulmonary vasospasm, causing hemodynamic collapse and profound left ventricular failure. Milrinone, a pulmonary vasodilator used in the management of emergent right ventricular failure, was administered via a nebulizer in an effort to decrease pulmonary vascular resistance. If used immediately after AFE, inhaled milrinone may mitigate pulmonary vasoconstriction, providing a bridge to extracorporeal membrane oxygenation.

The role of echocardiography in amniotic fluid embolism: a case series and review of the literature

PURPOSE

Amniotic fluid embolism (AFE) is a rare, but often fatal condition characterized by sudden hemodynamic instability and coagulopathy occurring during labour or in the early postpartum period. As the mechanisms leading to shock and the cardiovascular effects of AFE are incompletely understood, the purpose of this case series is to describe how AFE presents on echocardiography and review limited reports in the literature.

CLINICAL FEATURES

We describe three cases of AFE at the Jewish General Hospital, a tertiary care centre in Montreal, Canada. All cases met the Clark diagnostic criteria, which comprise 1) sudden cardiorespiratory arrest or both hypotension and respiratory compromise, 2) disseminated intravascular coagulation, 3) clinical onset during labour or within 30 min of delivery of the placenta, and 4) absence of fever. Two patients had a cardiac arrest and the third developed significant hypotension and hypoxia. In all patients, point-of-care echocardiography at the time of shock revealed signs of right ventricular failure including a D-shaped septum, acute pulmonary hypertension, and right ventricular systolic dysfunction.

CONCLUSION

This case series and literature review of AFE emphasizes the importance of echocardiography in elucidating the etiology of maternal shock. The presence of right ventricular failure may be considered an important criterion to diagnose AFE.

Venoarterial extracorporeal membrane oxygenation as an early treatment for amniotic fluid embolism with cardiac arrest: A case report

Amniotic fluid embolism (AFE) is a rare but fatal obstetric complication, characterized by sudden cardiovascular collapse, respiratory failure, and disseminated intravascular coagulation. Maternal mortality associated with AFE is high, making early recognition and prompt treatment important. In AFE with cardiac arrest, survival following acute cardiopulmonary dysfunction is crucial. In recent years, venoarterial extracorporeal membrane oxygenation (VA-ECMO) has attracted attention as an aggressive treatment for AFE with cardiac arrest. A 40-year-old woman experienced sudden cardiac arrest due to AFE during cesarean section. Cardiopulmonary resuscitation and VA-ECMO (also called percutaneous cardiopulmonary support) were initiated early. Finally, she recovered without any complications. VA-ECMO can provide temporary respiratory and hemodynamic support until cardiopulmonary function improves after a few days in intensive care. VA-ECMO should be considered as an early treatment for AFE with cardiac arrest.

Obstetric Hemorrhage

Peripartum hemorrhage is a leading cause of maternal morbidity and mortality. Anesthesiologists must be familiar with conditions associated with hemorrhage that are unique to labor and delivery and not seen elsewhere in their practice. Regardless of etiology, early recognition and timely treatment of obstetric hemorrhage is necessary to prevent significant blood loss. Massive transfusion protocols are crucial to successful resuscitation, and providers should also consider use of cell salvage, uterine artery embolization, and anti-fibrinolytics. Because more than half the deaths due to hemorrhage are preventable, multidisciplinary care bundles should be used on every labor and delivery unit.

[Maternal Deaths due to Amniotic Fluid Embolism in France 2013-2015]

Amniotic fluid embolism remains the 3rd cause of maternal death in France, with a stable rate and 28 deaths in this triennium, representing 10.7% of maternal deaths and a maternal mortality ratio of 1.2/100,000 live births. Cases are characterized by the suddenness of symptoms: the median delay between symptoms and death was 4h [0.75-696] with 20/28 patients did not reach the intensive care unit. Initial circulatory failure or cataclysmic haemorrhage was the two modes of presentation. Prodromes were reported in 17 (63%) cases and induction of labour was present in 12/27 (44%). One or more factors of sub-optimal care were present in 72% of the cases, and 52% of deaths were considered possibly or probably preventable. This preventability most often concerned the content of care but also the organisation of care (including human resources, communication, sites of care and referrals). The delay in establishing a well-conducted cardio-circulatory resuscitation or the delay in setting up an optimal transfusion strategy were the most frequent elements of substandard care. Absence or delay at hysterectomy during haemorrhagic situations was reported in 15/20 cases. The experts suggest being on the alert to diagnose amniotic embolism at an early stage, initiating intense resuscitation "outside the walls", envisaging a hysterectomy without delay if the haemorrhage is intense. On an organisational level, a "vital emergency maternity care" plan, specific to each establishment could be proposed.

Evolving Role of Anesthesiology Intensivists in Cardiothoracic Critical Care

The role of cardiothoracic anesthesiology intensivists has expanded over the past few decades. Cardiothoracic anesthesiology intensivists are taking on larger roles in cardiac critical care specializing in cardiogenic shock and extracorporeal membrane oxygenation.

Pulmonary Embolism in the Intensive Care Unit: Therapy in Subpopulations

The optimal management of a submassive or massive pulmonary embolism (PE) during pregnancy is unclear because of a lack of large clinical trials. Evaluation of the patient who may be a candidate for more aggressive therapy includes the use of biomarkers and echocardiogram for risk stratification. PE Response teams (PERTs) have gained increasing acceptance by the medical community and are being implemented in hospitals in the United States and worldwide. PERTs bring together a team of specialists from different disciplines to enhance decision-making in the patient with acute submassive and massive PE.

Identifiable relatives in the family history: not without individual consent

The family history is a traditional section of the clinical record. Data on family members in the clinical record may be anonymous but yet these may be easily identifiable; therefore, exposing the relatives of the patient to the fact that a written record is produced, mentioning them, without their consent. This is in direct contradiction with European data protection and other regulations and in contradiction with a reasonable ethical perspective. For the purpose of obtaining an image of the present state of affairs, we used as a convenience sample, the series of Case Records published in 2019 in The New England Journal of Medicine (January to December). From a total number of 40 reports, identifiable relatives were present in 30. The number of identifiable relatives varied between none and 6. It is not the right of each individual to disclose sensitive clinical information regarding other persons, without consent from these latter. Family history should no longer include identifiable relatives, unless consent is obtained from each identifiable person. The authors offer the following guidelines on this topic: (1) Do not mention any identifiable relative of the patient in the medical history without consent from the said relative; (2) Do not mention in the family history clinical conditions seemingly unrelated to the present clinical situation; (3) Do not mention in the family history clinical conditions that the patient does not (him/) herself have and that may be seen as social stigmata; (4) Consult the institutional Ethics committee in case of reasonable doubt.