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

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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