What are the guidelines for managing patients on Extracorporeal Membrane Oxygenation (ECMO) due to severe cardiac or respiratory failure?

Guidelines for Managing Patients on ECMO for Severe Cardiac or Respiratory Failure

ECMO should be considered for patients with severe, potentially reversible cardiac or respiratory failure who have failed conventional therapy, and should only be conducted in centers with sufficient experience (minimum 20 cases per year) and expertise in therapeutic modalities for severe acute respiratory failure. 1

Patient Selection and Indications

Respiratory Failure Indications

• Venovenous (VV) ECMO for severe ARDS with:
  • Very severe hypoxemia (PaO2/FiO2 < 80) for at least 3 hours despite optimal conventional management 2
  • Uncompensated hypercapnia with pH < 7.25 for at least 3 hours 2
  • Failure to respond to conventional therapies including:
    • Lung-protective ventilation strategies
    • Prone positioning
    • Higher PEEP without lung recruitment maneuvers 3
    • Neuromuscular blockade in early severe ARDS 3

Cardiac Failure Indications

• Venoarterial (VA) ECMO for:
  • Severe refractory cardiogenic shock
  • Refractory ventricular arrhythmia
  • During active cardiopulmonary resuscitation
  • Acute or decompensated right heart failure 4
  • Refractory pediatric septic shock 3

Contraindications

• Irreversible underlying condition
• Conditions incompatible with normal life
• Preexisting conditions significantly affecting quality of life
• Age and size limitations
• Contraindications to anticoagulation 1
• Neonates dependent on right-to-left shunting of blood (specific contraindication for inhaled nitric oxide) 5

ECMO Center Requirements

Staffing and Organization

• ECMO program director: Physician responsible for overall operation 3
• ECMO coordinator: Assists with training, staffing, quality improvement 3
• Multidisciplinary team including:
  • Physicians with ECMO expertise
  • Perfusionists or ECMO specialists
  • Critical care nurses (ratio 1:1 or 1:2 for ECMO patients)
  • Respiratory therapists
  • Surgeons for cannulation 1

Volume Requirements

• Minimum 20 ECMO cases per year for the entire center
• Minimum 12 ECMO cases for acute respiratory failure per year
• Centers should cover a catchment area of at least 2-3 million population 3

Physical Facilities and Equipment

• Wet-primed circuit available for immediate use (24/7)
• Backup components and supplies for all circuit components
• Uninterrupted power system supporting all equipment for at least 45 minutes
• Mobile ECMO cart and transport equipment
• Doppler echocardiography machines
• Surgical instruments for cannula revision or bleeding exploration 3

Management of Patients on ECMO

Ventilation Strategy

• Use lung-protective ventilation strategies during ECMO 3
• Limit tidal volume (4-8 mL/kg predicted body weight)
• Limit inspiratory pressures
• Consider higher PEEP without lung recruitment maneuvers 3
• Avoid prolonged lung recruitment maneuvers in moderate to severe ARDS 3

Anticoagulation Management

• Standard protocol:
  • Loading dose of 100 U/kg heparin before cannulation
  • Continuous infusion to maintain ACT between 180-220 seconds
  • Monitor multiple parameters: anti-FXa levels, PT, PTT, fibrinogen, platelet count, and AT III levels 1
  • Do not rely solely on ACT for anticoagulation management 1

Medication Considerations

• Consider corticosteroids for patients with ARDS on ECMO 3
• Consider neuromuscular blockers in early severe ARDS 3
• Monitor drug toxicity labs as drug metabolism may be altered 3
• For neonates with pulmonary hypertension, inhaled nitric oxide may be used to improve oxygenation and reduce ECMO need 5

Complication Management

• Bleeding complications (45-62% of cases):
  • Intracranial hemorrhage
  • Surgical site bleeding
  • Acquired von Willebrand syndrome (AVWS) 1
• Thrombotic complications (20-25% of cases):
  • Circuit thrombosis
  • Systemic thromboembolism 1
• Rebound pulmonary hypertension after discontinuation of inhaled nitric oxide 5
• Methemoglobinemia with nitric oxide therapy 5

Transport and Network Organization

Mobile ECMO Team

• Available 24/7 for patient retrieval
• Experienced personnel trained in:
  • Transport of critically ill patients
  • Insertion of ECMO cannulae
  • Circuit and patient management 3
• Team should include physicians, transport specialists, nurses, perfusionists, or other ECMO specialists 3

Network Organization

• Local, regional, or interregional networks of hospitals around each ECMO center
• Regular meetings between referral centers and network members
• Clear pathways for transition of care to centers capable of providing advanced cardiac therapies (VAD, transplant) 4

Weaning and Discontinuation

Weaning Protocol

• Assess possibility of weaning regularly with multidisciplinary team 6
• Do not determine futility solely by duration of ECMO 6
• For inhaled nitric oxide, avoid abrupt discontinuation to prevent rebound pulmonary hypertension 5
• Downtitrate in several steps, pausing at each step to monitor for hypoxemia 5

Transition Planning

• Consider advanced cardiac support options for patients unable to wean from VA ECMO:
  • Durable ventricular assist device
  • Heart transplantation 4
• For respiratory ECMO, consider prolonged support for lung recovery when appropriate 6

By following these comprehensive guidelines for ECMO management, clinicians can optimize outcomes for patients with severe cardiac or respiratory failure while minimizing complications associated with this complex therapy.