A heart-lung machine is connected by tubes, called cannulas, that interface your circulatory system with the machine. These cannulas both draw blood away from the body to be oxygenated and return the oxygenated blood.
Here's a more detailed breakdown:
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Cannulation: The process of inserting cannulas into the patient's blood vessels. This is typically done by a surgeon.
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Draining Blood: Cannulas are placed in veins (usually the vena cavae, which bring blood to the heart) to drain oxygen-poor blood from the body. This blood is then directed into the heart-lung machine.
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Oxygenation and Filtration: Inside the heart-lung machine, the blood is oxygenated and carbon dioxide is removed. It is also filtered.
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Returning Blood: Another cannula is placed in an artery (usually the aorta) to return the oxygen-rich blood back into the body's circulation. The aorta distributes oxygenated blood throughout the body.
In summary, the heart-lung machine provides a bypass for the heart and lungs by drawing blood, performing the functions of those organs, and then returning the blood to the body. This is achieved through cannulas that connect the machine to the patient's blood vessels.
