Extracorporeal Membrane Oxygenation Therapy
In 1995 Loma Linda University Children's Hospital launched the Extracorporeal Membrane Oxygenation (ECMO) therapy program for our region's most critically infants and children. Our team of extensively trained ECMO Specialists have saved the lives of hundreds of babies.
What is ECMO?
ECMO is a procedure that uses a machine to replace the work of the lungs and occasionally the heart. Extracorporeal means that the blood circulates outside of the body with the help of a machine. Membrane oxygenation acts as artificial lungs, which utilizes a special part of the machine to deliver oxygen into the blood and remove carbon dioxide. It is not a treatment or cure for heart or lung disease, rather it substitutes the work of the heart and lungs, allowing them to rest until the underlying problem is resolved. The support is gradually removed once the body has recovered enough to function on its own, this can range from several days to several weeks.
How Does ECMO Work?
Dark blood (containing little oxygen) is removed from the patient through a catheter placed in a large vein in the neck. The pump, which acts as a heart, pumps the blood through the tubing into the oxygenator, which acts as a lung, where it will pick up oxygen and remove carbon dioxide. The now oxygenated blood will appear bright red in color and is warmed and retruned to the child through another catheter. The blood leaving the body is simultaneously replaced with blood that was already been through the procedure so it mimics the body's natural process as much as possible.
Who Qualifies for ECMO?
Typically ECMO is necessary for children with a severe lung or heart condition that has not responded to our usual therapy of mechanical ventilation, medicine, and extra oxygen. Those needing ECMO may have one of the following conditions:
- Meconium Aspiration
- Respiratory Distress Syndrome
- Persistent Pulmonary Hypertension
- Diaphragmatic Hernia
- Cardiac Failure
Every child's medical needs are different, the need for ECMO is determined by the medical team responsible for the care of each individual child.
Types of ECMO?
There are two types of ECMO therapy:
- Venoarterial (VA)
- Venovenous (VV)
These terms refer to the blood vessels that are used during the ECMO procedure.
In VA ECMO, a catheter must be placed in both a vein and an artery. This technique give excellent support for the heart in addition to the lungs, and is the method of choice when heart function is concerned. It is also used in children with possible blood pressure problems who need the added support.
In VV ECMO, a single catheter is placed in a vein. It is used in children who have no significant heart or blood pressure issues since it is primarily used to support lung function. The advantage of this method is that the carotid artery is not altered as it is in the VA method.
What are the Risks of ECMO?
The most common complication during ECMO is bleeding. A blood thinner is given to the child to prevent clotting while the blood goes through the machine, this can lead to bleeding. The amount of the blood thinner given is closely monitored and all measures to minimize the risk of bleeding are taken. If bleeding does occur and cannot be controlled the ECMO therapy may have to be discontinued.
Whenever an invasive procedure is performed, such as placing a catheter into a blood vessel, there is an increased risk of infection. As a standard practice we give antibiotics as a precautionary measure and watch every child carefully for signs of infection.
Children on ECMO require frequent blood transfusions. Blood transfusions carry the risk of a blood reaction and transmitting a blood-borne illness such as hepatitis or AIDS. This risk is minimized by extensive screening performed by the blood bank in which we receive blood products, however there remains a very small risk that this can occur.
Small blood clots or air bubbles can get into the bloodstream from the line, this can be fatal in some circumstances. Every safety precaution is taken so that this does not occur.
A result of this procedure may involve tying off the carotid artery, which is one of the blood vessels that supplies blood flow to the brain. Although there are other blood vessels that will take over and carry blood to the brain, stroke is considered a long term risk as the child continues into adulthood. This complication is very rare and to date we have not had a patient experience this type of problem.