The ECMO candidate

ECMO (Extracorporeal Membrane Oxygenation) is a life-support technique used for patients with severe cardiac or respiratory failure who are unresponsive to conventional treatments. The criteria for initiating ECMO can vary depending on the specific clinical scenario, institution, and guidelines, but generally include the following:

Respiratory Failure (Veno-Venous ECMO – VV-ECMO):

Severe Hypoxemia:

• PaO₂/FiO₂ ratio < 80 mmHg despite optimal mechanical ventilation (e.g., high PEEP, FiO₂ > 90%).
• Oxygenation index (OI) > 40 (OI = [FiO₂ × Mean Airway Pressure × 100] / PaO₂).

Hypercapnia with Acidosis:

• pH < 7.20 with PaCO₂ > 60 mmHg despite optimal mechanical ventilation.

Refractory Respiratory Failure:

• Failure to maintain adequate oxygenation or ventilation despite maximal conventional therapy.
• Conditions such as ARDS (Acute Respiratory Distress Syndrome), pneumonia, or trauma.

Imminent Risk of Barotrauma:

• High ventilator pressures (e.g., plateau pressure > 30 cm H₂O) with risk of lung injury.

Bridge to Recovery or Transplant:

• Patients with potentially reversible lung disease or those awaiting lung transplantation.

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Cardiac Failure (Veno-Arterial ECMO – VA-ECMO):

Cardiogenic Shock:

• Refractory to inotropes, vasopressors, and intra-aortic balloon pump (IABP) or other mechanical support.
• Systolic blood pressure < 90 mmHg or cardiac index < 1.8 L/min/m² despite maximal support.

Cardiac Arrest (ECPR – ECMO for CPR):

• During or after cardiac arrest with unsuccessful conventional CPR.
• Ideally initiated within 60 minutes of arrest.

1. Acute Decompensated Heart Failure:

• Severe heart failure with end-organ dysfunction (e.g., renal or hepatic failure).

Post-Cardiotomy Shock:

• Inability to wean from cardiopulmonary bypass after cardiac surgery.

Bridge to Recovery, Transplant, or LVAD:

• Patients with potentially reversible cardiac injury or those awaiting heart transplantation or LVAD (Left Ventricular Assist Device).

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General Considerations:

Reversibility:

• The underlying condition should be potentially reversible or the patient should be a candidate for transplant or long-term mechanical support.

Age and Comorbidities:

• Younger patients with fewer comorbidities are generally preferred candidates.
• Advanced age or severe comorbidities may be relative contraindications.

No Contraindications:

• Absence of irreversible brain injury, advanced malignancy, or other conditions that would preclude recovery or transplantation.

Timing:

• Early initiation of ECMO before multi-organ failure develops is associated with better outcomes.

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Contraindications (Relative):

Irreversible Conditions:

• Severe brain injury, terminal malignancy, or other irreversible conditions.

Advanced Age:

• Age > 70-75 years (varies by institution).

Prolonged CPR:

• CPR duration > 60 minutes without adequate perfusion.

Severe Coagulopathy or Bleeding:

• Uncontrolled bleeding or high risk of hemorrhage.

Severe Multi-Organ Failure:

• Advanced liver or renal failure with poor prognosis.

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Monitoring and Weaning:

• Patients on ECMO require continuous monitoring of hemodynamics, oxygenation, and organ function.
• Weaning is considered when the underlying condition improves, and the patient can sustain adequate oxygenation and circulation without ECMO support.

These criteria are general guidelines and should be tailored to individual patient circumstances and institutional protocols.