What is ECMO? When does the patient need ECMO intervention?

Typically, people who need assistance use ECMO only for a few hours to a few days, but some people may need to use ECMO for a few weeks, depending on the course of the disease.

How is ECMO?

ECMO - Extracorporeal membrane oxygenation is a method of oxidation through the outer membrane of the body, using a circulatory system to perform oxygen exchange on the outside of the body to support and maintain maintenance of life function in patients with severe circulatory or respiratory failure.

Illustration of ECMO's operation.(Photo: JACC).

In it, extra-body circulation is a technique to temporarily replace heart and lung function when surgery is required to repair or replace large cardiovascular structures or blood vessels in the body.

Extracurricular circulation is performed thanks to artificial cardiopulmonary machines and must be controlled by specialized doctors and technicians.

This is a semi-closed system, which can completely replace the patient's heart and lung function thanks to the pumping system in combination with the gas exchange system connected to the patient's tubing, cannula and heart tank.

This system will create physiological changes in the body that are actively controlled changes such as arterial blood pressure, systemic blood pressure, pulmonary venous pressure, blood components. , partial pressure of CO ₂ , O ₂ , N ₂ and body temperature. This leads to self-regulating and self-protective reactions of the patient.

External circulatory system can completely replace or partially support the operation of the cardiopulmonary system, or it may be a complete replacement but placed simultaneously in many different cannula in different positions combined with stopping circulation. temporary.

Principle of operation of ECMO

The ECMO system is connected to the patient's body through plastic tubes (cannula tubes) placed in arteries, large veins in the legs, neck and chest.

The ECMO machine system draws blood from a patient's body pumped through an oxygen exchange membrane of the artificial lung system. Here, the dialysis fluid runs around the membrane, creating a difference in osmotic pressure and concentration, which is a condition for the exchange of fluids and solutes, and it also increases the amount of oxygen. in the blood and help eliminate carbon dioxide out.

Then, by using a pumping force equal to the force of the heart's contraction, ECMO helps return the exchange of gases and substances to the circulatory system.

There are two configurations of oxygen exchange through the outer membrane of the body: vein-vein and vein-vein. The venous-arterial configuration is used to ensure both gas exchange and hemodynamic support. The venous-vein configuration is mainly used to ensure the demand for oxygen and circulating volume for the body.

Simulate breathing machine operation (front) and ECMO (rear). (Video: Texas Children's Hospital) .

When do I need an ECMO intervention?

Patients who need to use ECMO are seriously ill patients who may be at risk for respiratory arrest or circulatory arrest.

ECMO is used when the lungs are not able to supply oxygen to the body even when oxygenated ventilation is supported, for example, severe pneumonia with respiratory distress, or patients diagnosed with acute pulmonary edema. accompanied by severe respiratory distress .

Or when the lungs cannot flush out carbon dioxide even with the help of a ventilator, the pumping action of the heart is insufficient to supply blood to the body.

Or may be indicated for cases of pulmonary heart disease and waiting for the organ to be transplanted.