Max Brinsmead MB BS PhDMay 2015

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

AFE – Risk FactorsMultiparityAbruptionIntrauterine Fetal DeathTumultuous labourOxytocin or Prostaglandin

hyperstimulationCaesarean sectionManual removal of the placenta

AFE - PathophysiologyProbably an anaphylactoid-type reaction to

the intravascular ingress of amniotic fluidThis causes widespread vasoconstriction

including pulmonary and cardiac vesselsThere is ↓myocardial contractility and acute left

heart failureIf the mother survives the initial cardiorespiratory

failure then DIC and haemorrhage is inevitableSurvivors may suffer stroke due to

cerebral infarctionThe presence of fetal amniotic squames in

the maternal lung at autopsy is said to be “diagnostic”

AFE – Clinical PresentationsAcute 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

AFE – DiagnosisThe diagnosis is a clinical oneExclude alternatives (if possible)

Placental abruptionUterine ruptureEclampsiaThromboembolismCardiogenic causes of acute CCFDrug toxicity e.g. Local anaestheticsAnaphylaxisTransfusion reactionMassive aspiration of gastric contents

Useful TestsBlood gasesECGBlood Coagulation testsLung CT to look for signs of thromboembolismSerum zinc coproporphyrin >35 nmol/L

AFE - Management Remember A, B, C Endotracheal intubation and IPPV

with 100% O2 ASAP Aggressive fluid replacement

preferably with CVP monitoringAggressive use of oxytocic agents plus

whatever to control PPH Pressor agents eg Dopamine usually

requiredMultidisciplinary Intensive Care

(including a haematologist) FFP and Platelets for DIC ?Heparin ?Factor VIIa