Maternal Arrest

Epidemiology and Risk Factors

  • Rare
    • 1:20,000 pregnancies with an OOHCA

Pathophysiology

Causes include:

  • Common
    • PE (29%)
    • Haemorrhage (17%)
    • Sepsis (13%)
    • Cardiomyopathy (8%)
  • Obstetric-specific
    • AFE
    • Neuraxial anaesthesia
    • Hypertensive disorders of pregnancy
  • Other
    • Poisoning and self-harm
    • Anaphylaxis

Key changes:

  • ↑ CO, VO2, and ↓ FRC
    Hypoxaemia occurs more quickly.
  • Gravid uterus compresses abdominal organs

Modifications to Standard Life Support

ALS:

  • Call for obstetrician and neonatologist
  • If >20 weeks or uterus palpable above the umbilicus:
    • Prepare for emergency hysterotomy
    • Manually displace the uterus, and place wedge to achieve lateral tilt
      15-30°.
  • Plan for early intubation ↑ Aspiration risk.
  • If indicated, perform emergency hysterotomy:
    • If resuscitation not successful within 4 minutes
    • Aiming for delivery within 5 minutes of arrest
      i.e. 1 minute between initiation of procedure and completed delivery.

References