Amniotic fluid embolus

Background

• Maternal mortality rate ~80%
• 85% of survivors have neurologic sequelae
• Occurs in 2-8 per 100,000 deliveries
  • Responsible for ~10% of maternal mortality in US

Risk Factors

• Cesarean delivery
• Advanced maternal age
• Abnormal placental implantation
• Uterine rupture
• Eclampsia
• Amniocentesis
• Trauma

Clinical Features

• Typically occurs during labor and delivery or 30 minutes after delivery
• Any of the following:
  • Respiratory distress
  • Pulmonary edema
  • Hypoxia
  • Altered mental status
  • Seizures
  • Sudden maternal cardiovascular collapse
  • DIC

Differential Diagnosis

3rd Trimester/Postpartum Emergencies

• Acute fatty liver of pregnancy
• Amniotic fluid embolus
• Chorioamnionitis
• Eclampsia
• HELLP syndrome
• Mastitis
• Peripartum cardiomyopathy
• Postpartum endometritis (postpartum PID)
• Postpartum headache
• Postpartum hemorrhage
• Preeclampsia
• Resuscitative hysterotomy
• Retained products of conception
• Septic abortion
• Uterine rupture

Evaluation

Post cesarean chest X-ray in a patient with acute amniotic fluid embolus.

Chest X-ray with diffuse infiltration throughout the lungs in a patient with acute amniotic fluid embolus.

Chest CT showing homogeneous ground-glass opacities in a patient with acute amniotic fluid embolus.

• Diagnosis of exclusion
• Consider CXR and/or chest CT

Management

• Treat hypoxia (may require intubation)
• Treat hypotension → Pressors / blood products
• Avoid hypoperfusion → Place patient in left lateral decubitus position
• Immediate delivery of fetus → Emergent c-section
  • Resuscitative hysterotomy within 5min of cardiac arrest if mother cannot be resuscitated

A-OK Medications

Only case reports have described the following three therapies

1. Atropine - 1mg IV
   • Vagolytic properties may help
2. Ondansetron 8 mg IV
   • Blocking of serotonin receptors can inhibits the release of more inflammatory mediators.
3. Ketorolac - 30mg IV
   • Can block thromboxane production and prevent coagulopathies.

Disposition

• Admit

See Also

• Postpartum emergencies