"The Key to Life" - The Miraculous Power of Extracorporeal Membrane Oxygenation (ECMO)

Author: Liang Liwen, First Affiliated Hospital of Air Force Medical University

Reviewer: Tao Ling, Chief Physician, First Affiliated Hospital of Air Force Medical University

Dear friends, have you ever thought about whether it is possible to regain vitality when our heart and lung functions are seriously failing? Perhaps many people's answer is no. But the good news is that the rapid development of modern medicine has opened a "door to rebirth" for us. Now, let's explore the mystery of extracorporeal membrane oxygenation (ECMO), an incredible "life machine". It can inject a ray of hope into people when their lives are in danger, and become the "priceless key" to open the door to life. Let's embark on this journey of exploration and appreciate the extraordinary power of cutting-edge technology!

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The mystery of ECMO

What is ECMO? What secrets are hidden behind this abbreviation? ECMO (extracorporeal membrane oxygenation) is a temporary life support system that drains blood outside the body, uses an artificial heart-lung machine (membrane oxygenator) to oxygenate and expel carbon dioxide, and then pumps the blood back into the body[1]. In short, ECMO temporarily replaces part of the functions of the heart and lungs to buy precious recovery time for severely failing organs.

The secrets of ECMO operation

Our heart and lungs are two vital organs of the human body. The heart is like an "oil transporter" that ensures that all organs get adequate blood supply. The lungs are the body's "air filter" that delivers oxygen to the whole body through breathing. Once this pair of "life partners" stops working for some reason, our lives will be in danger. ECMO replaces part of the heart and lung functions at this critical moment, seeking more treatment opportunities for patients.

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There are two working modes of ECMO[2].

(1) Pulmonary replacement (VV mode): This mode draws venous blood from the body, processes it through an artificial lung (oxygenation, removal of carbon dioxide), and then delivers it back to the venous system to help the lungs share the burden of breathing. In clinical practice, doctors usually choose a combination of femoral vein blood drainage and internal jugular vein blood return, and sometimes bilateral femoral veins are used for the operation.

(2) Cardiopulmonary replacement (VA mode): When the heart and lung functions are severely damaged, this "double-effect enhancement" mode comes in handy. It is to artificially oxygenate the venous blood immediately after it is drawn out, and then inject it into the arterial system in one go, completely "skipping" the heart and lungs, the "silent working partners". This mode usually draws blood from the femoral vein and then returns it to the femoral artery.

ECMO has a wide range of applications

ECMO can be called the “battlefield commander” of contemporary critical care medicine, and its application areas are astonishingly wide[3].

(1) Rescue of severe cardiopulmonary failure: For patients with cardiopulmonary failure, such as fulminant myocarditis, severe myocardial infarction, etc., ECMO can ensure that the body obtains the necessary oxygen and wins precious rescue time.

(2) Rescue of severe respiratory diseases: Whether it is pneumonia, lung abscess, or acute respiratory distress syndrome, the use of ECMO can promptly share the respiratory burden of the lungs and create favorable conditions for disease control and recovery. During the COVID-19 epidemic, ECMO also played an important role. Doctors used ECMO to reduce the lung burden of COVID-19 patients and help them survive the crisis of respiratory failure.

(3) "Escort" before and after high-risk surgery: Before performing high-risk surgery (such as high-risk percutaneous coronary intervention, or PCI), ECMO is used to provide patients with circulatory support to reduce the burden on the heart and lungs and "escort" the safety of the surgery.

Beware of complications and contraindications of ECMO

Although ECMO is powerful, it is not omnipotent. After all, ECMO needs to drain the body's blood out of the body, which deviates from the body's own physiological laws, so it is inevitable that there will be complications such as bleeding, thrombosis, and infection. Therefore, ECMO treatment is not recommended for the following situations: ① Active and uncontrollable bleeding; ② Advanced malignant tumors; ③ Severe damage to the central nervous system; ④ The primary disease cannot be reversed and there is no other treatment.

In addition, even if ECMO is implemented, we must closely monitor possible complications to prevent "loss of effort". Common complication risks [4] include: ① infection, such as blood infection, lung infection, etc. Strict aseptic operation and rational use of drugs are the key; ② bleeding, such as puncture site bleeding, gastrointestinal bleeding, etc. Closely monitor the patient's bleeding and take targeted prevention measures; ③ thrombosis, which requires timely anticoagulant treatment to prevent equipment failure; ④ nervous system damage, such as cerebral edema, intracranial hemorrhage, etc. Complications such as cerebral edema should be monitored and corresponding protective measures should be taken in a timely manner; ⑤ other organ damage, such as kidney damage, liver dysfunction, etc., which requires close attention to the function of organs such as kidneys and liver.

As a cutting-edge technology representing the level of medicine, ECMO has brought hope and courage to countless families. I believe that with the in-depth research and continuous improvement of ECMO in the future, ECMO will become safer and more convenient, adding new impetus to mankind's victory over disease!

References

[1] He Junqing, Chen Sisi, Cheng Rong, et al. Development trend of extracorporeal membrane oxygenation (ECMO) oxygenation membrane technology from the perspective of patents [J]. Science and Technology Review, 2023, 41(21): 98-113.

[2] Yang Zhenzhen, Xu Na, Zheng Wenyuan, et al. Clinical benefits of early cardiac rehabilitation in patients with extracorporeal membrane oxygenation[J]. Chinese Journal of Interventional Cardiology, 2023, 31(07): 521-525.

[3] Cao Liping, Gao Rui, Chen Na. Visual analysis of the current status of research in the field of extracorporeal membrane oxygenation at home and abroad from 2013 to 2023 based on CiteSpace[J]. Chinese Journal of Emergency Medicine, 2023, 43(08): 659-664.

[4] Ai Tingting, Liu Sijie. Complications related to extracorporeal membrane oxygenation and their prevention[J]. International Journal of Cardiovascular Diseases, 2023, 50(06): 383-386.