1. Amniotic Fluid Embolism
Max Brinsmead MB BS PhD
May 2015

2. Amniotic Fluid Embolism
A rare event – 3.3 per 100,000 deliveries in an Australian study based on ICD10
Was once associated with an 85% maternal mortality - 50% within the first hour
35% maternal mortality with modern intensive care and 32% perinatal mortality if it occurs before delivery

3. AFE – Risk Factors Multiparity Abruption Intrauterine Fetal Death
Tumultuous labour
Oxytocin or Prostaglandin hyperstimulation
Caesarean section
Manual removal of the placenta

4. AFE - Pathophysiology
Probably an anaphylactoid-type reaction to the intravascular ingress of amniotic fluid
This causes widespread vasoconstriction including pulmonary and cardiac vessels
There is ↓myocardial contractility and acute left heart failure
If the mother survives the initial cardiorespiratory failure then DIC and haemorrhage is inevitable
Survivors may suffer stroke due to cerebral infarction
The presence of fetal amniotic squames in the maternal lung at autopsy is said to be “diagnostic”

5. AFE – Clinical Presentations
Acute fetal distress followed quickly by maternal collapse with hypotension, dyspnoea and cyanosis
Sudden loss of consciousness or seizure
Often proceeds or occurs immediately after delivery
Maternal collapse during Caesarean section
Followed by profuse post partum haemorrhage

6. AFE – Diagnosis The diagnosis is a clinical one
Exclude alternatives (if possible)
Placental abruption
Uterine rupture
Eclampsia
Thromboembolism
Cardiogenic causes of acute CCF
Drug toxicity e.g. Local anaesthetics
Anaphylaxis
Transfusion reaction
Massive aspiration of gastric contents
Useful Tests
Blood gases
ECG
Blood Coagulation tests
Lung CT to look for signs of thromboembolism
Serum zinc coproporphyrin >35 nmol/L

7. AFE - Management Remember A, B, C
Endotracheal intubation and IPPV with 100% O2 ASAP
Aggressive fluid replacement preferably with CVP monitoring
Aggressive use of oxytocic agents plus whatever to control PPH
Pressor agents eg Dopamine usually required
Multidisciplinary Intensive Care (including a haematologist)
FFP and Platelets for DIC
?Heparin ?Factor VIIa