When is Veno-Venous (VV) Extracorporeal Membrane Oxygenation (ECMO) considered for a patient in severe respiratory failure?

From the Guidelines

Veno-Venous (VV) ECMO is considered for patients with severe respiratory failure when conventional mechanical ventilation fails to maintain adequate oxygenation or ventilation despite optimal management, as indicated by a PaO2/FiO2 ratio less than 80 mmHg despite high PEEP (>10 cmH2O) and FiO2 >80% for at least 3 hours, or pH <7.25 with PaCO2 >60 mmHg for over 6 hours, as supported by the most recent evidence 1.

Indications for VV ECMO

• Severe Acute Respiratory Distress Syndrome (ARDS)
• Pneumonia
• Status asthmaticus
• Bridge to lung transplantation

Considerations Before Initiating VV ECMO

• Reversible lung injury
• No absolute contraindications such as irreversible brain injury, terminal malignancy, or prolonged mechanical ventilation (>7 days)
• Careful assessment of potential benefits versus risks including bleeding, thrombosis, and infection, as highlighted in recent studies 1

Mechanism of VV ECMO

• Removes deoxygenated blood from a large vein
• Passes it through an oxygenator membrane where gas exchange occurs
• Returns oxygenated blood to the venous system, allowing the lungs to rest and heal while maintaining adequate tissue oxygenation

Recent Evidence and Recommendations

• The most recent study 1 emphasizes the importance of understanding the complex interplay between ECMO and acquired von Willebrand syndrome (AVWS) in patients supported by ECMO
• The study 1 suggests that VV ECMO can be indicated in patients with severe ARDS within 7 days after onset and with persistent life-threatening hypoxemia unresponsive to optimized supportive therapy
• The guideline 1 recommends considering VV ECMO in the process of invasive mechanical ventilation when the patient is still in the state of hypoxia, combined with increased partial pressure of carbon dioxide (excluding ventilation dysfunction, PaCO2 > 60 mmHg)

From the Research

Veno-Venous (VV) Extracorporeal Membrane Oxygenation (ECMO) Considerations

VV ECMO is considered for patients in severe respiratory failure when conventional treatments have failed. The decision to use VV ECMO is based on the patient's underlying condition and the risk of bleeding.

Indications for VV ECMO

• Severe respiratory failure due to adult respiratory distress syndrome (ARDS) 2
• Respiratory failure caused by diffuse alveolar hemorrhage 3
• Severe respiratory failure resulting from burns and smoke inhalation injury 4
• Critical respiratory failure accompanied by coagulopathy in multiple trauma patients 5

Patient Selection Criteria

• Patients with severe hypoxemic respiratory failure secondary to ARDS 2
• Patients with refractory respiratory failure who have failed conventional mechanical ventilation 6
• Patients with high risk of bleeding, where the use of ECMO with no initial anticoagulation could be considered a valid option 2

Management of VV ECMO

• Close vigilance and management of complications during ECMO 6
• Identification of strategies post-ECMO, such as recovery, transplantation, etc. 6
• Use of heparin-free VV ECMO in patients with high risk of bleeding 5
• Use of a heparin infusion keeping an activated clotting time (ACT) target shorter than 150 seconds in patients with moderate risk of bleeding 2