What is the management of an amniotic fluid embolism?

Management of Amniotic Fluid Embolism (AFE)

The management of amniotic fluid embolism requires immediate implementation of high-quality cardiopulmonary resuscitation with standard BCLS and ACLS protocols, followed by aggressive hemodynamic support and management of coagulopathy through massive transfusion protocols. 1

Initial Response and Stabilization

Immediate Actions

• Activate multidisciplinary team including anesthesia, respiratory therapy, critical care, and maternal-fetal medicine 1
• Initiate high-quality cardiopulmonary resuscitation (CPR) with ACLS protocols 1
• Consider immediate delivery in pregnancies ≥23 weeks gestation if cardiac arrest occurs 1
• Perform bedside transthoracic echocardiography to assess cardiac function, particularly right ventricular failure 2

Respiratory Support

• Secure airway with endotracheal intubation and mechanical ventilation
• Provide adequate oxygenation to maintain saturation >95% 1

Circulatory Support

• Avoid excessive fluid administration as it may worsen right ventricular failure 1
• Use vasopressors and inotropic agents based on hemodynamic status:
  • Norepinephrine to maintain blood pressure 1
  • Dobutamine or milrinone for right ventricular failure 1
  • Consider inhaled nitric oxide or prostacyclin for pulmonary hypertension 1

Management of Coagulopathy

Early Assessment and Intervention

• Perform early assessment of clotting status 1
• Activate massive transfusion protocol immediately 1
• Administer blood products in 1:1:1 ratio (packed red cells:fresh frozen plasma:platelets) 2
• Maintain platelet count above 50,000/mm³ 1
• Target fibrinogen levels >150-200 mg/dL with cryoprecipitate as needed 2

Monitoring and Additional Hemostatic Measures

• When available, use bedside thromboelastography to guide transfusion therapy 1
• Consider antifibrinolytics (tranexamic acid or epsilon aminocaproic acid) if hyperfibrinolysis is identified 1
• Recombinant activated Factor VII should only be considered as a last resort when hemorrhage cannot be controlled with standard measures 1

Management of Uterine Atony and Hemorrhage

• Aggressively manage uterine atony with uterotonics (oxytocin, ergot derivatives, prostaglandins) 1
• For refractory cases, consider:
  • Uterine tamponade with packing or intrauterine balloons
  • Bilateral uterine artery ligation
  • B-Lynch suture
  • Hysterectomy in extreme cases 1
• Thoroughly inspect cervix and vagina for lacerations in vaginal deliveries 1
• For diffuse bleeding during cesarean delivery not amenable to surgical control, consider packing the pelvis and transfer to ICU for delayed closure 1

Advanced Considerations

Refractory Cases

• For cases with prolonged CPR or severe ventricular dysfunction refractory to medical management, consider venoarterial extracorporeal membrane oxygenation (VA-ECMO) 2, 3
• If using VA-ECMO in the setting of coagulopathy, consider initiating without anticoagulation until bleeding tendency resolves 3

Differential Diagnosis

• Consider other causes of sudden cardiorespiratory collapse including:
  • Pulmonary embolism
  • Myocardial infarction
  • Air embolism
  • Anesthetic complications
  • Anaphylaxis
  • Eclampsia
  • Sepsis 1

Common Pitfalls and Caveats

• Do not delay blood product administration while awaiting laboratory results 1
• Avoid making the diagnosis of AFE based solely on hemorrhage from persistent atony with secondary coagulopathy 1
• Recognize that AFE typically presents with the classic triad of hypotension, hypoxia, and subsequent coagulopathy 1
• Be aware that the early phase is commonly characterized by right ventricular failure, while the second phase involves left ventricular failure and cardiogenic pulmonary edema 1
• Understand that AFE can rarely occur during first or second trimesters, pregnancy termination, or amniocentesis 1

Prognosis

The mortality rate of AFE remains high, with case fatality rates exceeding 50% in classic cases characterized by cardiovascular collapse and coagulopathy 1. However, with advances in acute care and early recognition, outcomes have improved in recent years 4.