VV-ECMO

VV-ECMO (veno-venous ECMO) is a type of temporary life support that takes over the work of your lungs when you have respiratory failure. A machine adds oxygen to your blood and removes carbon dioxide. This is called “gas exchange,” and it’s what your lungs normally do. The machine acts as an artificial lung, allowing your lungs to rest and heal.

Healthcare providers use VV-ECMO only when there’s a chance your lungs can recover their function or when you’re a candidate for a lung transplant. Typically, VV-ECMO is used only as a last resort, once it’s clear that medications or other treatments aren’t helping your lungs recover quickly enough.

VV-ECMO doesn’t treat the underlying cause of respiratory failure. But it can keep you alive while healthcare providers give you medications or do procedures to treat the issue.

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VV-ECMO keeps you alive when you’re in respiratory failure. A machine removes blood from a vein, adds oxygen to it, and sends it back into another vein for your heart to pump out to your body.

VV-ECMO can be lifesaving, but it comes with risks. The most common include bleeding, infections and blood clots, which may travel through your bloodstream and block blood flow.

Only certain hospitals are qualified to provide ECMO. These hospitals have highly trained teams of physicians, surgeons and other specialists who decide if ECMO is right for you. They review your health history and weigh the benefits and risks. They also decide if you need VV-ECMO or another type called VA-ECMO, which takes over for your lungs and heart.

How does VV-ECMO work?

A VV-ECMO machine removes blood from your veins and runs it through a special device, called a membrane oxygenator. The membrane adds oxygen and removes carbon dioxide. Another device, called a heat exchanger, keeps the blood warm enough to match your body temperature. Then, the machine pumps the blood back into your veins. From there, your heart receives the blood and pumps it out to your body.

The term “VV-ECMO” describes this process:

• Veno-venous: A machine removes blood from a vein and sends it back into another vein.
• Extracorporeal: This word means outside your body.
• Membrane: This is the part of the machine that adds oxygen to your blood and removes carbon dioxide.
• Oxygenation: This means your blood is gaining oxygen. That’s vital for keeping you alive.

VV-ECMO is different from VA-ECMO, which removes blood from a vein but sends it back into an artery. Another key difference is that with VV-ECMO, your heart is still able to meet your body’s needs. It’s only your lungs that need help. VA-ECMO, on the other hand, is used for people who have failing lungs and a failing heart.

What happens during VV-ECMO?

To connect you to VV-ECMO, your team of healthcare providers will:

1. Sedate you and give you anesthesia: These medications let you enter a painless sleep.
2. Place a drainage canula: Providers place a strong tube called a canula into a vein — typically the femoral vein in your groin — and guide its tip close to your heart. This tube drains blood from a large vein called your vena cava and sends it to the ECMO machine.
3. Place a return canula: Providers place another tube into another vein — typically the internal jugular vein in your neck. They guide its tip to your heart’s top right chamber. This tube sends oxygenated blood back into your heart, which pumps it out to your body.
4. Give you medication to prevent blood clots: Any time your blood touches artificial parts, like plastic tubing, there’s an increased risk of dangerous clots forming. Providers give you heparin to lower the risk.
5. Monitor you: Providers connect you to devices that constantly monitor blood pressure, blood oxygen levels and other vital signs. Your care team keeps a close eye on these monitors and adjusts the ECMO settings as needed.
6. Wake you up: If possible, your team wakes you up once setup is complete. But in some cases, you may need to stay sedated. They’ll do what’s best in your case.

How long will I need VV-ECMO?

It depends on your condition and how your body responds to treatment. Most people are on VV-ECMO for nine to 14 days. But some stay on it for four weeks or longer.

When your care team thinks your lungs are ready to take over again, they’ll wean you from ECMO. This means they gradually adjust the settings so your lungs take on more of the work and the machine does less. Weaning can take anywhere from several hours to days.

It’s possible that, despite treatments while on ECMO, you won’t show signs of recovery. When this happens, it may be necessary to remove you from ECMO. Hospital care teams discuss next steps with loved ones or others who can make health decisions on your behalf.

What is the outlook for a person on VV-ECMO?

Your outlook depends on the reason you need ECMO and how your body responds to treatment. Your care team can give you and your loved ones the most accurate sense of what to expect.