Extracorporeal membrane oxygenation

Overview

• aka ECMO
• Extracorporeal circuit, oxygenates blood and removes carbon dioxide, like an out-of-body lung
  • Can be high flow (1 venous line) or low flow (1 venous line)
• Types:
  • Veno-venous (VV)
    • Most common
    • Blood drained from central vein --> oxygenator --> vein near RA
    • Supports severe respiratory failure without cardiac dysfunction
  • Veno-arterial (VA): can be peripheral or central
    • Blood drained from central vein --> oxygenator --> aorta
  • Supports cardiac failure with or without respiratory failure
  • Veno-pulmonary artery
    • Blood drained from central vein --> oxygenator --> pulmonary artery
    • Short term right ventricular/respiratory support after LVAD placement

Indications

• Acute, severe respiratory or cardiac failure + REVERSIBLE cause + refractory to usual treatment + high risk of death
  • Poor gas exchange
  • Compliance < 0.5ml/cmH20/kg
  • P:F Ratio <100
  • Shunt fraction >30%
• Veno-venous (VV)
  • Pneumonia, ARDS, acute GVHD, pulmonary contusion, smoke inhalation, status asthmaticus, airway obstruction, drowning, bridge to lung transplant
• Veno-arterial (VA)
  • massive PE, nonischemic cardiogenic shock, failure of transplanted heart or heart-lung, cardiac or great vessel trauma, massive pulmonary hemorrhage/trauma, sepsis, anaphylaxis, drug overdose, bridge to LVAD

Contraindications

• Absolute
  • >120 kg
  • unwitnessed cardiac arrest
  • non-reversible, progressive cardiac disease in a patient who is not a transplant candidate
  • non-reversible, progressive respiratory disease
  • severe, chronic pulmonary hypertension
  • advanced cancer
• Relative
  • older than 75 years
  • multisystem trauma
  • CNS injury
  • multiple organ failure
• VV
  • unsupported cardiac failure, cardiac arrest, severe pulmonary hypertension, significant immunosupression
• VA
  • Aortic dissection or severe aortic regurgitation