Amniotic Fluid Embolism (AFE)
OVERVIEW
- diagnosis of exclusion
- amniotic in maternal circulation not always pathognomonic
- 1:25,000 live births
- 3rd most common cause of maternal death (UK)
- 1st most common cause of maternal death (Australasia)
- mortality 50% in first hour -> if patients survive usually have neurological deficits.
PATHOPHYSIOLOGY
- uncertain
- probably due to an anaphylactic reaction to fluid or fetal tissue
- intravascular entry of prostaglandins, leukotrienes, endothelin and fetal debris
- within 30min -> complement activation + intense pulmonary vasoconstriction -> right heart failure -> hypoxia, hypercarbia & acidosis -> left heart failure + APO
CLINICAL FEATURES
No typical presentation! -> ‘Classic’ triad = hypoxia, haemodynamic collapse, DIC
- APO/ALI (>90%)
- Cardiac arrest (>90%)
- Fetal distress (100%)
- SOB
- Bronchospasm
- Cough
- Arrhythmia
- Chest pain
- Seizure
- Headache
- Uterine atony
RISK FACTORS
- Age > 25 yrs
- Multiparous
- Obstructed labor with oxytocics
- Short labour
- Maternal history of allergy or atopy
- Chorioamnionitis
- Meconium liquor
- Polyhydramnios
- Placental abruption
- Uterine rupture
- IUFD
DIAGNOSIS
- clinical grounds
- specific antigen testing of maternal bloods can help
- plasma concentration of zinc coproporphyrin (a component of meconium)
MANAGEMENT
Supportive!
- Call for help – anaesthetic, obstetric, haematological, ICU, paediatric, midwifery
Goals:
(1) Prompt recognition
(2) Prompt resuscitation
(3) Early delivery of fetus
- A – ETT (RSI)
- B – FiO2 1.0 + PEEP
- C – CPR + left uterine displacement, IVF, inotropes, PAC may be needed -> initially develop right heart failure then this recovers and left heart begins to fail -> treat left sided heart failure aggressively
- Early delivery of fetus vital for both patients – if mum having CPR delivery within 5 min.
- Manage coagulopathy
- Oxytocics + bimanual massage & uterine packing +/- hysterectomy may be indicated.
- ICU Admission
- Notify Local Data Collection Agency
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC