What is ECMO?
During cardiac arrest, blood cannot carry oxygen to the brain, causing brain cells to decay irreparably, making recovery uncertain. CPR, in which circulation is manually stimulated to delay brain damage, has long been considered the last chance for patients.
However, with ECMO, those same patients can be brought back from the brink and kept alive while doctors work toward diagnosis and treatment, making CPR seem primitive by comparison. This high-tech method of resuscitation is known as ECPR and could mark a revolution in medical practice if adopted by hospitals worldwide.
How does it work?
An extracorporeal membrane oxygenation machine (ECMO) is an advanced life-support apparatus. Two catheter needles are inserted, one into a major vein and one into a major artery, allowing a synthetic pump to begin drawing blood out of the body, circulating it through the apparatus, before returning it to the bloodstream. The blood passes through a membrane oxygenator, in which oxygen is introduced and carbon dioxide removed, much like the exchange of gases that takes place in the lungs.
Some ECMO machines also include a heat exchanger, which can cool or warm the blood according to the patient’s condition.
A dedicated team is required to place a patient on ECMO, but once that patient is stabilized, the machine can be supervised by specially trained nurses and can maintain stability for sustained periods.
This allows the patient to live without a functioning cardiopulmonary system for days or even weeks, giving diseased organs a valuable holiday in which to recover.
When is it used?
Until recently, it has been used largely for severe lung failure in babies. In the UK, it is principally thought of as an intensive care treatment used in the ward, but more and more US hospitals are adding ECPR to their emergency treatment options.
In an emergency, when a patient has shown no return of spontaneous circulation after conventional CPR, a doctor would decide whether the patient merits being attached to an ECMO machine, which must be carried out in a matter of minutes.
Emergency ECMO is therefore administered as a last resort to patients who stand a good chance of full recovery.