ECMO

 

How does it work:

Components

·      Draining cannula

·      Pump

·      Membrane oxygenator

·      Return cannula

Types

Common:

·      VV (lung bypass)

·      VA (heart + lung bypass)

Uncommon:

·      VAV

·      VVA

·      VPA (with LVAD)

Workflow

·      Insertion: OT if central, ICU if peripheral

·      Maintenance: need protocols

·      Weaning: ensure heart and lungs are working properly

·      Decannulation: OT if central, ICU if peripheral

 

Decision making:

Indications

Cardiac:

·      Cardiac arrest

·      Failure to wean from CPB

·      Fulminant myocarditis

·      Acute cardiomyopathy e.g. peri-partum

·      Pulmonary embolism

·      Toxidromes

·      Heart transplant failure

Respiratory:

·      ARDS e.g. flu

·      Lung transplant failure

·      Pulmonary vasculitis

·      Pulmonary haemorrhage

Contraindications

·      Advanced age

·      Severe comorbidities

·      Acute multi-organ failure

 

Complications:

Body

·      Bleeding (brain, cannula sites)

·      Thrombosis

·      Embolism (brain, gut, limb)

·      Infection

·      Vessel injury

·      Limb ischaemia (peripheral VA)

·      Differential hypoxia (central VA)

o  Central VA ECMO only

o  Branches of proximal aorta get blue blood

o  Put sats probe on the right hand

Machinery

·      Access insufficiency (e.g. against vessel wall)

·      Accidental decannulation

·      Draining circuit breach -> air embolism

·      Return circuit breach -> bleeding

·      Oxygenator failure (accumulation of fibrin etc)

·      Pump failure

Drugs

·      Large increase in central volume of distribution

·      Oxygenator sequesters lipophilic, highly protein-bound drugs

·      Risk of both inefficacy and toxicity

·      Careful with a) anaesthetic b) vasopressor c) anticoagulant

 

 

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