Amniotic Fluid Embolism (AFE)

Rare, often fatal obstetric emergency — anaphylactoid syndrome of pregnancy. Sudden hemodynamic collapse, hypoxemia, and DIC during labor, delivery, or postpartum (within 30 min).

Recognition

•Sudden hypotension, hypoxemia, altered mental status near delivery
•DIC within minutes (uncontrolled bleeding from puncture sites, uterine atony)
•Cardiac arrest in 1/3 of cases
•Differential: PE, anaphylaxis, eclampsia, peripartum cardiomyopathy

Steps

1
Call code blue + OB + maternal-fetal medicine
2
ACLS — left uterine displacement
Prepare for perimortem C-section ≤4 min into arrest.
3
Secure airway + 100% O₂
Most patients require intubation.
4
A-OK protocol
Atropine 1 mg + Ondansetron 8 mg + Ketorolac 30 mg IV — anti-PG/anti-vagal cocktail.
5
Massive transfusion protocol
1:1:1 (PRBC:FFP:platelets), cryo, fibrinogen concentrate.
6
Vasopressors + inotropes
NE first-line; epi for cardiac dysfunction; vasopressin pulmonary-sparing.
7
Inhaled NO or milrinone for RV failure
Pulmonary HTN often the proximate cause of cardiac arrest.
8
Consider VA-ECMO if available + refractory

Drugs + doses

Drug	Dose	Note
Atropine	1 mg IV (A-OK)
Ondansetron	8 mg IV (A-OK)
Ketorolac	30 mg IV (A-OK)
Norepinephrine	0.05–1 mcg/kg/min
Vasopressin	0.04 U/min infusion
Cryoprecipitate	10 U for fibrinogen < 200
TXA	1 g IV over 10 min

Pitfalls

!Mortality 20–60% even with optimal care — early recognition is everything.
!Don't delay perimortem C-section — fetal + maternal survival both improve.
!Avoid lactated Ringer's during massive transfusion (calcium binds citrate).

Sources

SMFM Consult Series 2016
Pacheco Obstet Gynecol 2020
AANA Position Statement

Anatomy reference

Sourced reference images. 4 matches for "uterus pulmonary circulation".

EB1911_Tunicata_-_Blood_Circulation_in_an_Ascidian

Wikimedia · Public domain

Wikimedia · CC BY 4.0

The_capillary_circulation_of_the_lungs._Wellcome_M0010777

Wikimedia · CC BY 4.0

The_Capillary_Circulation._Wellcome_M0010778

Wikimedia · CC BY 4.0

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Education only — not a substitute for facility protocols, MOC certification, or clinical judgment. Always follow your institutional crisis algorithm and confirm doses against current package inserts.