Extracorporeal Membrane Oxygenation (ECMO)

Extracorporeal membrane oxygenation (ECMO) is a life-support therapy used to support the heart and lungs when they are unable to function properly. It is a type of extracorporeal circulation, which means that it involves circulating blood outside of the body.

Indications for ECMO

ECMO is typically used in critically ill patients who have severe and potentially reversible cardiac or respiratory failure. The indications for ECMO include:

• Severe acute respiratory distress syndrome (ARDS)
• Cardiogenic shock
• Myocarditis
• Pulmonary embolism
• Post-cardiotomy cardiac failure
• Bridge to heart transplantation or lung transplantation

How ECMO Works

The ECMO circuit consists of a few key components:

• A cannula, which is inserted into a major blood vessel (usually the femoral vein or artery) to drain deoxygenated blood from the body
• A pump, which propels the blood through the circuit
• A membrane oxygenator, which removes carbon dioxide and adds oxygen to the blood
• A heat exchanger, which regulates the temperature of the blood
• A return cannula, which returns the oxygenated blood to the body

The ECMO circuit can be configured in two main modes:

• Veno-venous (VV) ECMO: This mode is used for respiratory support only. Deoxygenated blood is drained from a vein, oxygenated, and then returned to a vein.
• Veno-arterial (VA) ECMO: This mode is used for both cardiac and respiratory support. Deoxygenated blood is drained from a vein, oxygenated, and then returned to an artery.

Benefits of ECMO

The benefits of ECMO include:

• Ability to support the heart and lungs during severe failure
• Potential for recovery of cardiac and respiratory function
• Bridge to transplantation or other definitive therapy
• Improved survival rates in certain patient populations

Risks and Complications of ECMO

The risks and complications of ECMO include:

• Bleeding and thrombosis due to anticoagulation requirements
• Infection and sepsis
• Cardiovascular instability
• Neurological complications (e.g. stroke, seizures)
• Renal failure
• Multi-organ dysfunction syndrome

Contraindications for ECMO

The contraindications for ECMO include:

• Severe and irreversible brain damage
• Advanced age (usually >65 years)
• Severe and irreversible organ dysfunction (e.g. liver, kidney)
• Prolonged cardiopulmonary resuscitation (>30 minutes)
• Absence of potential for recovery or transplantation

ECMO Team and Management

The ECMO team typically consists of:

• Cardiothoracic surgeons
• Intensivists (critical care physicians)
• Perfusionists
• Nurses with specialized training in ECMO management
• Respiratory therapists

The management of ECMO requires close monitoring and adjustment of the circuit, as well as careful attention to the patient's overall clinical status.

Frequently Asked Questions (FAQs)

What is Extracorporeal Membrane Oxygenation (ECMO)?
A life-support therapy used to support the heart and lungs when they are not functioning properly.

When is ECMO typically used?
In cases of severe respiratory or cardiac failure, such as acute respiratory distress syndrome (ARDS) or cardiogenic shock.

How does ECMO work?
By pumping blood outside the body to a membrane oxygenator, which removes carbon dioxide and adds oxygen before returning it to the body.

What are the types of ECMO?
Venovenous (VV) ECMO for respiratory support and venoarterial (VA) ECMO for cardiac support.

What are the benefits of ECMO?
Can provide life-sustaining support, allowing the heart and lungs to rest and recover from injury or illness.

What are the risks associated with ECMO?
Bleeding, infection, blood clotting, and potential damage to organs such as the kidneys or liver.

How long can a patient be on ECMO?
Typically several days to several weeks, depending on the underlying condition and response to treatment.

Can ECMO be used in pediatric patients?
Yes, ECMO is sometimes used to support newborns and children with severe respiratory or cardiac failure.

Is ECMO a cure for underlying conditions?
No, ECMO is a supportive therapy, not a cure, and is often used as a bridge to other treatments, such as lung transplantation or cardiac surgery.

What is the survival rate for patients on ECMO?
Varies widely depending on the underlying condition, age, and other factors, with reported survival rates ranging from 20-60%.