What is the management of suspected amniotic fluid embolism?

Management of Suspected Amniotic Fluid Embolism

Immediate high-quality cardiopulmonary resuscitation with standard basic and advanced cardiac life support protocols is the cornerstone of management for suspected amniotic fluid embolism (AFE), followed by targeted interventions for respiratory support, hemodynamic stabilization, and aggressive management of coagulopathy. 1

Initial Recognition and Diagnosis

• AFE should be considered in any pregnant or immediately postpartum woman who experiences:

  • Sudden cardiovascular collapse or cardiac arrest
  • Severe respiratory difficulty or hypoxia
  • Seizures
  • Unexplained coagulopathy 2, 1

• No specific diagnostic laboratory test can confirm or refute AFE diagnosis; it remains a clinical diagnosis 2

• Bedside echocardiography showing right ventricular dysfunction favors AFE over other conditions 2

Immediate Management Algorithm

1. Cardiopulmonary Support

• Initiate high-quality CPR if cardiac arrest occurs:

  • Chest compressions at 100/minute
  • Compression depth of at least 2 inches
  • Allow complete chest recoil between compressions 2, 1

• For undelivered patients:

  • Tilt patient to left lateral decubitus position or
  • Have an assistant manually displace the uterus laterally to prevent aortocaval compression 2

• Perform early echocardiography (transthoracic or transesophageal) to identify right ventricular failure 3

2. Respiratory Management

• Administer oxygen to maintain saturation >95%
• Consider early intubation for respiratory distress 1

3. Hemodynamic Stabilization

• For right ventricular failure:
  • Administer inotropes: dobutamine (2.5-5.0 μg/kg/min) or milrinone (0.25-0.75 μg/kg/min) 1, 3
  • Use vasopressors to maintain mean arterial pressure ≥65 mmHg
  • Avoid excessive fluid administration as it can worsen right ventricular failure 2, 3

4. Coagulopathy Management

• Perform early assessment of clotting status 2
• Activate massive transfusion protocol immediately:
  • Use hemostatic resuscitation with 1:1:1 ratio of packed red cells, fresh frozen plasma, and platelets
  • Administer cryoprecipitate as needed to maintain serum fibrinogen >150-200 mg/dL 1, 3
• Consider antifibrinolytics such as tranexamic acid for bleeding 1

5. Delivery Management

• If cardiac arrest occurs with a fetus ≥23 weeks gestation, perform immediate delivery 2, 1
• For post-delivery uterine atony:
  • Aggressively manage with uterotonics (oxytocin, ergot derivatives, prostaglandins)
  • For refractory cases, consider uterine tamponade with packing or intrauterine balloons
  • Extreme cases may require bilateral uterine artery ligation, B-Lynch stitch, or hysterectomy 1

Advanced Considerations

• For prolonged cardiac arrest or severe ventricular dysfunction refractory to medical management, consider venoarterial extracorporeal membrane oxygenation (VA-ECMO) 3
• Maintain serum glucose between 140-180 mg/dL with insulin infusions if needed 1
• Consider targeted temperature management (36°C) in patients without significant bleeding or coagulopathy 1

Multidisciplinary Approach

A multidisciplinary team including anesthesia, respiratory therapy, critical care, and maternal-fetal medicine should be involved in the ongoing care of women with AFE 2, 1

Common Pitfalls and Caveats

• Avoid diagnosing AFE based solely on hemorrhage from persistent atony with secondary coagulopathy 2
• Consider alternative diagnoses such as pulmonary embolism, air embolism, anesthetic complications, anaphylaxis, eclampsia, transfusion reactions, and sepsis 2
• Recombinant factor VIIa may lead to increased mortality and should not routinely be used 4
• For diffuse bleeding after cesarean delivery not amenable to surgical control, consider packing the pelvis and transfer to ICU for delayed closure 1

While some emerging therapies like C1 esterase inhibitors 4 and atropine-ondansetron-ketorolac (AOK) 5 have been proposed as potential treatments, they are not yet part of standard management guidelines and require further research before routine implementation.