Extracorporeal membrane oxygenation (ECMO)
Extracorporeal membrane oxygenation (ECMO) is a critical medical technique that temporarily takes over the function of the heart and lungs by oxygenating a patient's blood outside the body. This method is primarily used for infants with underdeveloped lungs, but it can also benefit older children and adults facing severe respiratory or cardiac issues. ECMO operates using a machine that removes deoxygenated blood, oxygenates it through a membrane, and returns it to the body, effectively acting as an artificial lung.
There are two main types of ECMO: veno-venous (VV) ECMO, which is utilized when lung function is primarily affected, and veno-arterial (VA) ECMO, which supports both heart and lung function. While ECMO has been lifesaving for many, it is typically reserved for cases where all other treatment options have been exhausted, and patients may have only a 20% chance of survival before the procedure, improving to about 60% during treatment.
Despite its potential to save lives, ECMO carries significant risks, such as infection and bleeding, due to the invasive procedures involved. Careful monitoring is essential, and treatment is generally temporary, allowing the patient's body to gradually resume normal function. Follow-up care varies based on individual patient needs.
On this Page
Extracorporeal membrane oxygenation (ECMO)
Extracorporeal membrane oxygenation, or ECMO, is a medical technique that uses mechanical means to replace a person's spent blood with freshly oxygenated blood. It is most often used for infants whose lungs are underdeveloped or who have other problems. However, it can be used on older children and adults as well. It can also be used to help a patient awaiting surgery to fix a problem with the heart or lungs or to help a patient survive while natural and/or medically assisted healing is taking place. ECMO is only used for short periods, ranging from a few days to about a month, and it is often utilized only in cases in which all alternatives have been exhausted.
Background
Extracorporeal membrane oxygenation refers to the process of using an artificial lung (membrane) to replace the oxygen supply in a person's body (oxygenation) while that blood is outside the body (extracorporeal). It uses a relatively large machine similar to the heart/lung machines used to support a person during heart surgery. It has tubes that remove blood that has circulated through the body and used up its oxygen. The blood flows through these tubes into the machine and through the membrane, which uses special equipment to remove the carbon dioxide from the blood and add oxygen. The blood is then pumped back into the body through special tubes.
There are two main types of ECMO. Veno-venous, or VV ECMO, uses veins for both removing and returning blood to the patient. This process is utilized when the patient's condition mainly affects the lungs. Veno-arterial, or VA ECMO, removes the blood from a vein and puts it back through an artery. This type of ECMO is used when the patient's condition also affects the heart. It is a more serious form of the procedure because it sometimes requires that the carotid artery, the primary artery connecting the heart to the brain, be sealed after the patient is removed from ECMO.
Overview
ECMO has been used since 1975, and the procedure helps nearly three thousand infants a year. Many of these infants are born prematurely and have underdeveloped lungs. ECMO helps keep the child alive while the lungs mature to the point where they can provide adequate oxygen. The process is also used on infants who breathe in meconium, which is the first stool passed by a child. When meconium is passed before or during birth, the child can breathe it in and develop a condition known as meconium aspiration syndrome. ECMO may also be used for children who have persistent pulmonary hypertension, certain kinds of hernias or holes in the diaphragm muscle that separates the stomach area from the chest, congenital heart conditions, sepsis infections, or pneumonia.
Older children and adults may also be treated with ECMO if they have certain heart conditions or a severe case of pneumonia. ECMO may also be appropriate for patients who have experienced an accident or breathed in poisonous chemicals. It can be used for patients who have severe asthma or severe infections and for those who are undergoing heart surgery. Additionally, ECMO can help keep patients of all ages alive for short periods while they await a heart and/or lung transplant.
Patients who are placed on ECMO have several tubes entering and exiting their bodies. These include breathing tubes connected to a ventilator to provide oxygen to the lungs and remove secretions, intravenous tubes to administer medications, and cannulas, which are placed into the groin, neck, or chest to remove and replace blood. The patient is usually sedated when placed on ECMO and throughout its use. Medical professionals carefully observe patients on ECMO and monitor their condition with chest X-rays and other tests.
ECMO is a serious procedure, and it is generally used for patients who have life-threatening conditions. In most cases, all alternative procedures have been exhausted before ECMO is recommended. It is estimated that most patients have only a 20 percent chance of living when they are placed on ECMO. The survival rate is generally improved to about 60 percent when ECMO is used.
Although ECMO can save lives, it carries significant risks that increase the longer the patient continues the treatment. One significant risk is infection. Anytime the skin is broken, the body is more susceptible to infection. ECMO requires several surgical incisions to place tubes and needle punctures for intravenous lines and blood tests. Feeding tubes and ventilator tubes are also used. All of these have the potential to introduce an infection. The patient may also acquire an infection from transfused blood if it is needed to supplement the patient's own supply.
Bleeding is also a risk during ECMO. Drugs such as heparin are used to prevent the blood from forming life-threatening clots during the transfer process. These drugs, called anticoagulants, work by thinning the blood. This prevents clots but also increases the chance of uncontrolled bleeding.
In addition, equipment issues could cause the ECMO machinery to fail. Emergency procedures are used to help the patient if this should happen. However, since patients on ECMO are already seriously ill, machinery failure may result in death.
ECMO is meant to be a temporary treatment. When patients improve and are able to be removed from the machinery, the physician will start by reducing the amount of blood that is processed through the machine. This allows the patient's body to take over the functions that had been handled by the machine. A ventilator will often be used for a time even after the patient is removed from ECMO. Follow-up care will depend on the patient's specific condition.
Bibliography
Aokage, Toshiyuki, et al. "Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome." Journal of Intensive Care, vol. 3, no. 17, 17 June 2015, jintensivecare.biomedcentral.com/articles/10.1186/s40560-015-0082-7. Accessed 26 Dec. 2016.
"Extracorporeal Membrane Oxygenation." MedlinePlus, medlineplus.gov/ency/article/007234.htm. Accessed 26 Dec. 2016.
"Extracorporeal Membrane Oxygenation." University of California San Francisco, www.ucsfhealth.org/treatments/extracorporeal‗mechanical‗oxygenation/. Accessed 26 Dec. 2016.
"Extracorporeal Membrane Oxygenation: ECMO." Children's Hospital of Philadelphia, www.chop.edu/treatments/extracorporeal-membrane-oxygenation-ecmo. Accessed 26 Dec. 2016.
"Extracorporeal Membrane Oxygenation (ECMO)." Cincinnati Children's Hospital, www.cincinnatichildrens.org/health/e/ecmo. Accessed 26 Dec. 2016.
Makdisi, George, and I-wen Wang. "Extra Corporeal Membrane Oxygenation (ECMO) Review of a Lifesaving Technology." Journal of Thoracic Disease, vol. 7, no. 7, July 2015, www.ncbi.nlm.nih.gov/pmc/articles/PMC4522501/. Accessed 26 Dec. 2016.
Moores, Danielle. "ECMO (Extracorporeal Membrane Oxygenation)." Healthline, 22 June 2012, www.healthline.com/health/extra-corporeal-membrane-oxygenation. Accessed 26 Dec. 2016.
Rodriquez-Cruz, Edwin, et al. "Pediatric Extracorporeal Membrane Oxygenation." Medscape, 26 Dec. 2016, emedicine.medscape.com/article/1818617-overview?pa=mj5CFjiXGTT5R7eLP%2BxccD2t3deFZz%2BxN8YdeK1ahYYZM%2B8Eev0h3mBbylc61nQJDRsmUx34vavLwMZtBQAYWbOwhd8Mdk7tVO%2FdkscsGC4%3D. Accessed 26 Dec. 2016.