Extracorporeal membrane oxygenation (English: extra-corporeal?membrane?oxygenation, abbreviated ECMO), is a medical or emergency device that provides breathing and circulation outside the body for patients during cardiopulmonary surgery, such as procedures for severe heart and lung failure and heart transplantation.
Also used in first aid, ECMO was first successfully utilized by the University of Michigan Medical School in the U.S. In addition to temporarily replacing a patient's cardiopulmonary function and reducing the burden on the patient's heart and lungs, ECMO also buys more time for medical staff to save the patient's life.
The use of ECMO in pediatric patients is usually limited to a week to a few days due to complications, while the use of ECMO in adult patients is much longer. The guidelines for the use of ECMO are set by the Extracorporeal Life Support Organization (ELSO), a group of experts in the field.
History of development
ECMO was first invented by John Gibbon in the 1950s, and continued to be developed by Clarence Walton Leahy. Due to the early immaturity of purely mechanical extracorporeal support systems, Lillahay used the bold experiment of using a living human being as an extracorporeal support system for the patient, and demonstrated its efficacy by using it for the first time in a newborn infant in 1965.
In 1972, Robert H. Bartlett, a surgeon at the University of Michigan, successfully used it for the first time in the treatment of patients with acute respiratory distress.
Extended information:
Basic Principles
When ECMO is in operation, blood is drawn from a vein, oxygenated through the membranopulmonary oxygenation, and carbon dioxide is expelled, and the oxygenated blood can be returned to the vein (V-V diversion) or to the artery (V-A diversion).
I. V-V diversion:
Mainly used for extracorporeal respiratory support, the venous blood has been partially exchanged before flowing through the lungs, to make up for the insufficiency of the lung function.V-V diversion through the vein will be the venous blood out of the oxygenation through the oxygenator oxygenation and elimination of carbon dioxide pumped into another vein. The femoral vein is usually chosen for drainage and the internal jugular vein is pumped in, or both femoral veins can be chosen according to the patient's condition.
V-V diversion is indicated in cases of purely impaired pulmonary function without risk of cardiac arrest.V-V diversion only partially replaces pulmonary function because only a portion of the blood is preoxygenated and there is recirculation through the tubing. Repeated circulation phenomenon means that part of the blood is pumped into the vein through the ECMO line and then sucked into the ECMO line, repeating the oxygenation.
Second, V-A diversion:
It can be used for both extracorporeal respiratory support and cardiac support, and the blood pump can replace the pumping function of the heart to maintain blood circulation.V-A diversion draws venous blood from the vein, and then pumps it into the arteries after oxygenation and elimination of carbon dioxide through the oxygenator.V-A diversion is a kind of connection to support the cardiorespiratory function at the same time, and it is suitable for cardiac failure, pulmonary function, and severe failure with cardiac arrest. severe failure with potential for cardiac arrest.
The extracorporeal circulatory line of V-A diversion is connected to the heart and lungs in parallel, and the operation increases cardiac afterload and reduces the amount of continuation page flow through the lungs, which can lead to pulmonary edema and even pink foamy sputum during prolonged operation. In addition, when the heart stops completely, the blood in the heart stagnates in the V-A mode and is prone to thrombosis, which can lead to irreversible damage.
ECMO mode should be chosen flexibly with reference to the cause and condition. Generally speaking, V-V diversion is the lung alternative mode, and V-A diversion is the combined cardiopulmonary alternative mode.
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