Patient education: Extracorporeal membrane oxygenation (ECMO) (The Basics)

What is extracorporeal membrane oxygenation? — Extracorporeal membrane oxygenation (ECMO) is a very serious form of life support. ECMO can support the heart, lungs, or both. It is used when a person is very ill, has life-threatening lung or heart failure, and has not gotten better with other treatments.

Most people who need ECMO are only on it for a few days. But in some cases, they are on ECMO for a few weeks.

When is ECMO used? — Doctors might order ECMO for very serious conditions like:

●"Congenital diaphragmatic hernia" or "meconium aspiration syndrome" in children

●Lung problems like pneumonia, respiratory failure, near drowning, pulmonary hypertension, or a serious air leak

●Heart problems like heart defects, heart attack, shock, or problems following a heart transplant

●Problems before or after a heart or lung transplant

●Very bad infections like coronavirus disease 2019 (COVID-19)

When a person is on ECMO, their lungs and heart have a chance to rest and heal.

How does ECMO work? — The ECMO machine can do the work of the lungs and heart. This allows the blood to "bypass" these organs so they can rest and recover (figure 1).

The ECMO machine pumps the person's blood through an artificial lung or "oxygenator." Here, oxygen is added and carbon dioxide is removed from the blood. This allows the lungs to rest. Then the ECMO machine pumps the blood back to the body. This allows the heart to rest. The blood is also warmed before it is returned to the body.

There are 3 types of ECMO:

●Venous-arterial or "VA" ECMO

●Venous-venous or "VV" ECMO

●Venoarterial-venous or "VAV" ECMO

The doctor will choose the type of ECMO based on whether your heart or lungs need more support.

How do I prepare for ECMO? — ECMO is most often done in an emergency, when a person is very sick. Sometimes, doctors might put a person on ECMO at the end of a surgery.

The doctor will order tests to make sure the person's body can handle ECMO. They might include:

●Ultrasound of the head

●Chest X-ray

●Blood tests

●Echocardiogram (to look at the heart)

What happens during ECMO? — ECMO is done in the hospital's intensive care unit, or "ICU." The doctor will first decide what area to use for the procedure. It might involve blood vessels in the upper thigh, chest, or neck.

The doctor cleans the area and places 1 or more tubes (called a "cannula") into large blood vessels (figure 1):

●For venous-arterial (VA) ECMO, the doctor might place 2 tubes: 1 into a vein and 1 into an artery

●For venous-venous (VV) ECMO, they might only place 1 tube into a vein. Or they might place 2 tubes in 2 different veins.

The tubes are carefully stitched in place and covered with a bandage. The doctor will do an X-ray or ultrasound to make sure the tubes are in the right place. Then they will attach the tubes to the ECMO machine.

The person's own blood is removed by the ECMO machine. It is usually dark red because oxygen levels are low. The blood is brighter red after it gets oxygen added and is pumped back to the person's body. The doctors and nurses will do tests and monitor the person to make sure the blood is flowing properly.

The person's breathing tube is left in place during ECMO. The doctor might adjust the settings on the breathing machine so the lungs can rest some more.

A special team of doctors, nurses, and others care for people on ECMO. The staff will carefully monitor the person's heart rate, blood pressure, and oxygen levels. While on ECMO, people also have to be on medicines to prevent blood clots. These medicines are sometimes called "blood thinners." They help keep blood clots from forming, but they can also make it easier to bleed. The staff will also do frequent blood tests and check the dose of blood thinner to make sure it is correct. They will also give blood transfusions (extra blood) if needed.

What happens after ECMO? — As the person's condition gets better, the doctors can turn down the ECMO machine to see if the lungs and heart are ready to work on their own. If so, they can stop ECMO. Then, the doctor takes the tubes out of the blood vessels. Often the person is still very sick, even after ECMO.

What are the downsides of ECMO? — ECMO does come with many risks. These include:

●Bleeding or blood clots, often in the brain or lung, respectively

●Infection

●Injury to other organs

●Problems with platelets in the blood

●Problems with the equipment like the tubing breaks, the pump stops, or the cannula moves out of place

●The lungs and heart do not get better

●Death

What else do I need to know? — When a person is on ECMO, they are very sick. The person will have a lot of equipment attached to them in addition to the ECMO pump. Most people have a breathing tube and ventilator, many IVs, and a catheter (tube) to drain urine. But in rare cases, they can be awake and even walk a little.

While ECMO can allow a person's body to rest and recover, there is a chance that they will not get better. This depends on how sick the person is and why they needed ECMO. The doctors and nurses are always available to answer questions.

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Patient education: COVID-19 overview (The Basics)
Patient education: Heart transplant (The Basics)
Patient education: Lung transplant (The Basics)