Amniotic fluid embolism: diagnosis and management

Diagnosis/definition: 

• Triad of sudden hypoxia and hypotension, followed in many cases by coagulopathy, all occurring in relation to labor and delivery
• DDX in any women with sudden cardiovascular collapse or cardiac arrest seizures, severe respiratory difficulty or hypoxia, particularly if such events are followed by a coagulopathy that cannot be otherwise explained
• DDX (long): myocardial infarction, pulmonary embolism, air embolism, anesthetic complications, anaphylaxis, and eclampsia and sepsis
• Period of anxiety, change in mental status, agitation, and a sensation of “doom” may precede the event
• May progress rapidly to cardiac arrest, with pulseless electrical activity (PEA), asystole, ventricular fibrillation, or pulseless ventricular tachycardia
• DIC is present in up to 83% of cases 
• Diminished uterine perfusion, uterine atony

Epidemiology/Incidence: 

• AFE is so rare that there are no risk factors sufficiently established to justify any alteration in standard obstetric care
• 70% of cases of AFE occur during labor, 11% after a vaginal delivery, and 19% during a cesarean delivery

Management: 

Screening/Work-up:

• The use of any specific diagnostic laboratory test to either confirm or refute the diagnosis of AFE is not recommended at the present time; AFE remains a clinical diagnosis. (GRADE 1C)

Cardiac Arrest

• Immediate high quality cardiopulmonary resuscitation  with standard BCLS and ACLS protocols in patients who develop cardiac arrest associated with AFE. (GRADE 1C) 
• Involvement of a multidisciplinary team including anesthesia, respiratory therapy, critical care, and maternal-fetal medicine should be involved in ongoing care of such women. (Best Practice)
• Use of vasopressors, anti-arrhythmic agents, and defibrillating doses is not different than those utilized in non- pregnant individuals
• Preparations for emergent perimortem cesarean should be initiated simultaneously with initiation of CPR – if the cardiac arrest is still ongoing as the instruments become available, proceed with cesarean delivery
• Following cardiac arrest with AFE, we recommend immediate delivery in the presence of a fetus > 23 weeks of gestation. (GRADE 2C)

Post cardiac arrest management

• Fluids, vasopressors, and inotropes with the goal is to maintain a mean arterial blood pressure of 65 mmHg
• Fever may worsen ischemia-reperfusion injury to the brain and should be aggressively treated
• Hyperoxia will also worsen ischemia-reperfusion injury, and administration of 100% oxygen after survival of cardiac arrest should be avoided
• The inspired fraction of oxygen should be weaned to maintain a pulse oxymetry value of 94%-98%
• Serum glucose should be maintained between 140-180 mg/dL with the use of insulin intravenous infusions if needed

 Coagulopathy

• Coagulopathy may follow cardiovascular collapse with AFE, early assessment of clotting status and early aggressive management of clinical bleeding with standard massive transfusion protocols is recommended (GRADE 1C)

Last Reaffirmed: Aug 1, 2022