HomeDiseaseCOVID-19ECMO: what it is, how it works and possible complications

ECMO: what it is, how it works and possible complications

ECMO, or extracorporeal membrane oxygenation, is a machine that provides support for the respiratory and / or cardiac system, generally used for babies, but which can also be indicated for children and adults with severe pulmonary or cardiac diseases, when there is a risk of that the lungs or heart stop working properly.

This machine works like an artificial lung allowing the necessary oxygenation of the body while treating the cause, such as lung infection, shock after heart attack or severe acute respiratory syndrome caused by COVID-19.

ECMO is used only in the ICU, in hospitals, and its use must be indicated by the medical team. Generally, ECMO is used for a few hours a day, and the person must be sedated and receive food support through a nasogastric tube or parenteral nutrition. Understand what nasogastric tube feeding or parenteral nutrition is.

What is it for

ECMO is used when the lungs cannot supply enough oxygen to the body, even when oxygen is already being received through a nasal catheter, or when the lungs cannot get rid of carbon dioxide, even with the help of a mechanical ventilator.

In addition, this machine can also be used when the heart cannot pump enough blood to the body.

Thus, the main indications for ECMO include:

  • Severe pneumonia;
  • Severe lung infections;
  • Respiratory failure;
  • Acute respiratory syndrome;
  • Congenital hernia in the diaphragm;
  • Aspiration of toxic substances by the lungs;
  • Meconium aspiration by babies;
  • Asthma;
  • Pulmonary hypertension;
  • Cardiac insufficiency;
  • Congenital heart defects;
  • Cardiac surgery;
  • Generalized infection.

In addition, ECMO can be indicated for people with heart or lung disease that cannot be cured while waiting for a heart or lung transplant.

Can ECMO be used in cases of COVID-19?

The World Health Organization (WHO) has recommended the use of ECMO for people with COVID-19, who have acute respiratory distress syndrome with severe respiratory failure, low blood oxygenation and do not improve with the use of mechanical ventilation [1].

The use of ECMO is also recommended by the Extracorporeal Life Support Organization (ELSO) for people with severe COVID-19 infection, depending on the financial resources of the hospital and the training of the health team to use the machine. In these cases, the doctor should also make a regular assessment of the patient’s viral load [2].

In addition, the American Respiratory Care Association (AARC) recommends using ECMO only for adults with severe acute respiratory syndrome caused by COVID-19 [3].

However, ECMO has contraindications for use, especially for the elderly and people who already have a disease such as diabetes, chronic lung disease, heart failure or who are on prolonged mechanical ventilation, because in these cases the risk of mortality due to COVID- 19 is high.

It is important to note that ECMO can help a person recover from severe COVID-19, but it does not treat the disease or fight the coronavirus.

How it works

ECMO uses a type of artificial lung that is connected to the body through tubes connected in arteries of the leg, neck or chest. These tubes collect blood from the body, which enters the machine in order to receive oxygen and remove carbon dioxide. Then the blood is returned to the body to oxygenate all tissues. This means that ECMO, completely replaces the function of the lungs and helps in pumping the heart.

When using ECMO, the doctor must indicate the use of heparin, an anticoagulant, which is used to prevent blood from forming small clots in the tubes, which can cause complications, such as stroke or infarction. In addition, it is also common for a person to receive blood transfusions during treatment.

How is recovery

Recovery after using ECMO is done slowly, as the doctor must gradually reduce the amount of blood oxygenated by the machine as the person improves and, after turning the machine off completely, the person must remain on a mechanical ventilator , for a period of time established by the doctor and which varies from person to person.

In addition, people who have used ECMO should be closely monitored to treat the disease that caused respiratory or heart failure.

Possible complications

The biggest complication of ECMO is the risk of bleeding, due to the use of heparin, which is used to prevent blood clotting during the use of the machine. Therefore, blood tests are performed frequently to assess blood clotting and prevent bleeding.

Other complications that can arise with the use of ECMO are infection by insertion of the tubes or by blood transfusions that the person must receive while using the ECMO.

In addition, there is also an increased risk of clots forming in ECMO cannulas, which can result in stroke.

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