What are the indications for Extracorporeal Membrane Oxygenation (ECMO)?

Indications for Extracorporeal Membrane Oxygenation (ECMO)

ECMO should be considered as a rescue therapy for patients with severe, potentially reversible cardiorespiratory failure when conventional medical therapies have failed or are likely to fail. 1

Types of ECMO and Their Primary Indications

Venovenous (VV) ECMO - Respiratory Support

• Indicated for severe acute respiratory failure with:
  • PaO₂/FiO₂ < 80 mmHg for at least 3 hours despite optimal ventilation 2, 3
  • pH < 7.25 with hypercapnia for at least 3 hours despite optimal ventilation 3
  • Failure of conventional ventilation strategies and rescue therapies (prone positioning, neuromuscular blockade, inhaled nitric oxide/prostacyclin) 2
• Common clinical scenarios:
  • Severe ARDS (Acute Respiratory Distress Syndrome) 4, 3
  • Severe pneumonia 4
  • Respiratory failure due to trauma 4
  • Primary graft failure following lung transplantation 4
  • Inhalation injuries/poisoning with respiratory failure 2

Venoarterial (VA) ECMO - Cardiac and Respiratory Support

• Indicated for:
  • Severe refractory cardiogenic shock 5
  • Refractory ventricular arrhythmias 5
  • Active cardiopulmonary resuscitation for cardiac arrest (ECPR) 5, 6
  • Acute or decompensated right heart failure 5
• Common clinical scenarios:
  • Post-cardiotomy cardiogenic shock 4
  • Post-heart transplant failure 4
  • Severe cardiac failure due to cardiomyopathy, myocarditis, or acute coronary syndrome 4

Timing of ECMO Initiation

• VV-ECMO should be initiated within 7 days of respiratory failure onset for optimal outcomes 2
• For VA-ECMO in cardiac arrest (ECPR), rapid initiation is critical to improve neurologic outcomes 6
• Early consideration is recommended before irreversible end-organ damage occurs 1

Patient Selection Considerations

• ECMO should be considered for patients with potentially reversible cardiorespiratory failure 1
• Factors supporting ECMO use:
  • Young age with fewer comorbidities 1
  • Potentially reversible etiology (e.g., viral pneumonia, status asthmaticus) 1
  • Failure of conventional therapies 2
• Relative contraindications:
  • Irreversible cardiac or pulmonary disease without transplant options 5
  • Severe, irreversible neurological injury 5
  • Prolonged cardiac arrest without adequate CPR 6
  • Multiple organ failure 5

Institutional Requirements

• ECMO should only be performed at centers with sufficient experience, volume, and expertise 1
• Centers caring for more than 20-25 ECMO cases per year have significantly better outcomes 1, 2
• The learning curve to establish competence requires at least 20 cases for optimal results 1, 2
• Recommended minimum annual volume is 20 cases per year for the entire center, with at least 12 ECMO cases for acute respiratory failure 1
• Centers should maintain expertise in the care and ventilatory management of patients with severe acute respiratory failure 1

Special Considerations

• Mobile ECMO teams should be available for retrieval of patients from centers without ECMO capability 1
• Hospitals without ECMO capability should establish relationships with ECMO-capable institutions for timely transfer 2
• ECMO may serve as a bridge to recovery, transplantation, or more permanent mechanical support devices 4, 5
• AVWS (Acquired von Willebrand Syndrome) develops in almost all ECMO patients within hours of device implantation and may contribute to bleeding complications 1

Cautions and Pitfalls

• ECMO is a complex, high-risk, and costly modality that should be used judiciously 1
• Bleeding complications are common and associated with high mortality rates, particularly intracranial hemorrhage 1
• Thrombotic and thromboembolic complications can occur despite anticoagulation 1
• Evidence supporting ECMO use in some indications remains limited, and further clinical trials are needed 1
• Concentration of complex care at high-volume centers with advanced cardiac capabilities may improve outcomes 5