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).
⚡ Rehearsal mode
Walk the algorithm step by step
8 steps · click-through one at a time. Forces you to pre-read each action before moving on — the way you should rehearse the real thing.
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
- 1Call code blue + OB + maternal-fetal medicine
- 2ACLS — left uterine displacementPrepare for perimortem C-section ≤4 min into arrest.
- 3Secure airway + 100% O₂Most patients require intubation.
- 4A-OK protocolAtropine 1 mg + Ondansetron 8 mg + Ketorolac 30 mg IV — anti-PG/anti-vagal cocktail.
- 5Massive transfusion protocol1:1:1 (PRBC:FFP:platelets), cryo, fibrinogen concentrate.
- 6Vasopressors + inotropesNE first-line; epi for cardiac dysfunction; vasopressin pulmonary-sparing.
- 7Inhaled NO or milrinone for RV failurePulmonary HTN often the proximate cause of cardiac arrest.
- 8Consider 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".
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📊 Related teaching panels
Standalone diagrams matched to this topic.
Panel 1 of Anesthesia for non-obstetric surgery in pregnancy
Anesthesia for non-obstetric surgery in pregnancy
Panel 1 of Anesthesia for non-obstetric surgery in pregnancy
Anesthesia for non-obstetric surgery in pregnancy
Panel 1 of Anesthesia for non-obstetric surgery in pregnancy
Anesthesia for non-obstetric surgery in pregnancy
Panel 1 of Anesthesia for non-obstetric surgery in pregnancy
Anesthesia for non-obstetric surgery in pregnancy
Other crisis algorithms
- Malignant Hyperthermia (MH)
Hypermetabolic crisis triggered by volatile anesthetics or succinylcholine in genetically susceptible patients (RYR1, CACNA1S). Treat with dantrolene immediately.
- Perioperative Anaphylaxis
IgE-mediated (or pseudo-allergic) hemodynamic collapse from drug, latex, or transfusion exposure. Most common triggers in OR: NMBAs (rocuronium, succinylcholine), antibiotics, latex.
- LAST (Local Anesthetic Systemic Toxicity)
Cardiovascular and CNS toxicity from inadvertent IV injection or systemic absorption of local anesthetic. Bupivacaine highest cardiotoxicity. Ropivacaine + lidocaine slightly safer.
- Laryngospasm
Reflex closure of the vocal cords from light-anesthesia airway stimulation. Common in pediatrics, recent URI, and emergence. Untreated → hypoxia → bradycardia → arrest.
- High / Total Spinal
Cephalad spread of neuraxial local anesthetic causing apnea + cardiovascular collapse. Most common with epidural-to-subarachnoid migration in OB.
- Intraoperative Pulmonary Embolism
Sudden ↑PA pressure → RV failure → cardiovascular collapse. May be thrombus, fat (long-bone fracture, IM rod), gas (laparoscopy CO₂, sitting craniotomy), or amniotic.