AFE

AMNIOTIC FLUID EMBOLISM

Speaker: Jayne Needham
Year: 2025

LEARNING OUTCOMES

  • Recognize features of this rare condition.

  • Understand the need for prompt action and involvement of both obstetric and anaesthetic teams.

  • Discuss current recommendations in light of evidence.

  • Acknowledge the importance of maintaining up-to-date basic life support measures.

INTRODUCTION

  • Amniotic Fluid Embolism (AFE) is a rare complication of pregnancy.

  • Incidence: Difficult to estimate; however, all suspected cases should be reported to the National Amniotic Fluid Embolism Register.

HISTORY

  • The first case of AFE was reported in 1926.

  • In 1817, there was a case of unexplained fetal and maternal death considered relevant to AFE.

  • AFE was first included in the Confidential Enquiry from 1955-57.

  • According to MBRRACE 2023, there were 8 deaths reported during the years 2019-2021 related to AFE.

DESCRIPTION

  • In the UK, if a previously healthy asymptomatic woman experiences cardiac or respiratory failure during labour, at lower segment caesarean section (LSCS), or immediately post-birth, AFE should be suspected (Boyle, 2016).

CONSIDERATIONS

  • The presence of amniotic fluid in the maternal circulation triggers an anaphylactoid reaction; thus, the term 'embolus' can be misleading.

  • AFE is usually associated with a tear in the membranes.

  • It can occur during caesarean sections and may also happen during termination of pregnancy.

OTHER FACTORS

  • AFE can occur at any gestational age.

  • Most cases occur after the onset of labour.

  • The onset of AFE is totally unpredictable.

PREDISPOSING FACTORS

  • Placental Abruption

  • Uterine Over-Distension

  • Fetal Death

  • Trauma

  • Oxytocin-Stimulated Labour

  • Multiparity

  • Advanced Maternal Age

  • Rupture of Membranes

PATHOPHYSIOLOGY

  • AFE involves several physiological events:

    • Transient pulmonary vasospasm occurs, leading to acute anaphylactic responses to amniotic fluid, fetal hair, meconium entering the maternal circulation rather than the fluid itself, causing obstruction.

    • This results in left ventricular failure, which leads to pulmonary oedema and hypotension.

    • Neurological effects may include seizures, confusion, and coma.

    • Disseminated intravascular coagulation can occur, leading to uncontrollable uterine bleeding, as well as bleeding from puncture sites.

EFFECTS ON FETUS

  • Changes may be observed on electronic fetal monitoring (EFM) even before maternal symptoms manifest.

  • Possible effects include:

    • Decreased uterine perfusion.

    • Decreased uterine blood flow.

    • Rapid depletion of fetal reserve.

    • Signs of hypoxia observed, resulting in a non-reassuring cardiotocography (CTG).

DIAGNOSIS

  • Until recently, AFE was diagnosed primarily post-mortem.

  • Diagnosis is now based on clinical features and the presentation of symptoms.

SIGNS AND SYMPTOMS

  • Key signs and symptoms of AFE include:

    • Respiratory Distress / Cyanosis

    • Hypotension

    • Pulmonary Oedema

    • Shock

    • Neurological Manifestations

    • Cardio-Respiratory Arrest within Minutes

    • Coagulopathy

MANAGEMENT

  • Advanced Cardiac Life Support (ACLS) is critical.

  • Implement Continuous Fetal Monitoring.

  • Ensure proper Oxygenation and circulation are maintained.

  • Control of any bleeding is paramount.

  • Consider Fetal well-being during management.

  • Offer Family Support during the crisis.

DISCUSSION OF CASES

  • From 2019 to 2021, 8 cases were reported and published in 2023.

    • Five of these women who died underwent induction of labour.

    • Three women died following a caesarean section.

    • Six women succumbed on the day of giving birth, while two others died within three days post-birth.

    • One of the women was admitted to intensive care after initial resuscitation but later died.

RECOMMENDATIONS

  • Ensure early involvement of senior staff in suspected AFE cases.

  • All staff must be up to date with basic life support techniques.

  • Conduct regular emergency drills to prepare for potential AFE incidents.

  • Consider attendance at Advanced Life Support in Obstetrics (ALSO) and Managing Obstetric Emergencies and Trauma (MOET) courses.

FURTHER RECOMMENDATIONS

  • All suspected or proven AFE cases should be reported to the National Amniotic Fluid Embolism Register.

  • Staff should be vigilant regarding sudden changes in a woman’s behaviour, which may indicate an impending AFE.

  • Emphasize the importance of staying current with medical practices and guidelines.

CONCLUSIONS

  • The number of maternal deaths due to AFE remains relatively stable.

  • AFE is considered a rare, unpredictable condition that can progress rapidly.

  • Management strategies are primarily supportive.

  • Maternal outcomes improve with timely access to intensive care units (ITU).

  • Early recognition facilitates quicker action from appropriate medical teams.

  • It is crucial to keep up to date with advancements in understanding and managing AFE.