Cardiopulmonary bypass is a procedure that supports many surgeries, including CABG. Another name for it is being “on the pump," which means a heart-lung machine takes over for your heart and lungs during your surgery. The machine adds oxygen to your blood before pumping it back out to nourish your body.
Cardiopulmonary bypass is a procedure that diverts blood circulation away from your heart and lungs. It’s a routine part of many heart surgeries. “Cardio” refers to your heart, and “pulmonary” refers to your lungs. “Bypass” means to avoid something by going around it. So, cardiopulmonary bypass allows your blood to avoid your heart and lungs during your surgery.
Instead of flowing through your heart and lungs, your blood drains into a machine outside your body. This machine is a cardiopulmonary bypass machine, or a heart-lung machine. This machine takes over the jobs of your heart and lungs. These jobs include adding oxygen to your blood, removing carbon dioxide from your blood and then pumping this refreshed blood back into your body.
Another name for cardiopulmonary bypass is being “on the pump.” Usually, if you’re on the pump, your surgeon will also use medication (cardioplegia solution) to stop your heart from beating. Cardiopulmonary bypass with cardioplegia allows your surgeon to perform surgery on a still (non-beating) heart. This procedure also allows the rest of your body to receive the oxygen-rich blood it needs to survive.
No, they’re not the same. But they often occur together. And they both involve a “bypass,” or a detour around something.
CABG stands for coronary artery bypass grafting. This surgery creates a detour around one or more blockages in your coronary arteries. It helps people who have plaque buildup due to coronary artery disease. Your surgeon creates a new path for blood to flow to your heart.
Cardiopulmonary bypass is a procedure that often supports CABG. So, healthcare providers perform the procedures at the same time. Cardiopulmonary bypass creates a detour for blood to flow away from your heart and lungs. This helps your surgeon perform CABG more easily and safely.
People who have the following surgeries may need cardiopulmonary bypass:
Typically, open-heart surgery requires cardiopulmonary bypass. But some people who need coronary artery bypass grafting (CABG) may benefit from off-pump bypass surgery. This type of open-heart surgery doesn’t use a heart-lung machine. Instead, your surgeon uses a device to stabilize your heart during the surgery. So, your heart still beats during the surgery. That’s why another name for off-pump surgery is “beating heart” surgery.
Talk with your provider about the method that’s better for you.
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Cardiopulmonary bypass creates a circuit for blood to flow outside your body, avoiding your heart and lungs. The heart-lung machine takes over the functions of your heart and lungs throughout your surgery. Its key responsibilities include:
The cardiopulmonary bypass (heart-lung) machine consists of many parts, including:
Additional tubes connect the parts together. All of these parts form a circuit that replaces the usual work of your heart and lungs. So, to understand how the heart-lung machine works, it’s helpful to know how your heart and lungs normally manage blood flow.
Each time your heart beats, blood flows through your heart and lungs to gain oxygen. Oxygen-poor blood from your body enters your heart through large veins called your superior and inferior vena cava. These veins drain blood into the top right chamber of your heart (right atrium). From there, your blood flows through the right side of your heart and into your lungs.
In your lungs, your blood gains oxygen before returning to the left side of your heart. The bottom left chamber of your heart (left ventricle) pumps this blood out to your body through your aorta.
So, when this circuit is complete, your blood has traveled through both sides of your heart and your lungs. It now has oxygen and is ready to nourish your body.
During some surgeries, your surgeon needs to access your heart without blood flowing through it. So, the normal circuit needs to pause. But your body still needs the oxygen-rich blood that the circuit provides. That’s where the heart-lung machine steps in.
The heart-lung machine creates a detour outside your body for your blood to receive oxygen. The detour begins at the right side of your heart and works like this:
Your surgical care team manages the heart-lung machine throughout your surgery. Your care team includes your surgeon, anesthesiologist and perfusionist. Perfusionists are medical professionals who have special training in managing cardiopulmonary bypasses.
Your care team connects you to the heart-lung machine and monitors you throughout the surgery. After your surgery, your care team slowly weans you from the heart-lung machine so that your heart and lungs can begin working on their own again.
To conduct cardiopulmonary bypass, your care team must perform the following steps:
When you’re off the pump, your care team continues to monitor your levels before transferring you to the intensive care unit (ICU) for recovery.
Cardiopulmonary bypass allows your body to receive oxygen-rich blood during your surgery. It takes over the work of your heart and lungs so your surgeon can work in a still and bloodless space.
As with any procedure involving your heart, cardiopulmonary bypass carries risks. Talk with your healthcare provider about the risks and how your surgical care team will manage them. In general, the risk of complications increases the longer you need to be on the pump. Your risk also depends on your health before the surgery.
Possible complications include:
Surgeons try to keep people on cardiopulmonary bypass for the shortest time possible. Generally, your risk of complications is lower if you’re on the pump for under three hours.
Your healthcare provider is the best person to ask about your recovery. It varies based on the type of procedure you had, your medical history, your age and how long you were on the pump. Talk with your provider about what you can expect after your surgery.
Your provider will tell you when you need to come in for follow-up appointments. Be sure to keep all of your appointments and follow your provider’s instructions closely. Call your provider any time you have questions or concerns about your recovery.
Call 911 or your local emergency number if you have symptoms of a stroke. These include:
A note from Cleveland Clinic
Cardiopulmonary bypass helps surgeons perform life-saving operations every day. It’s an essential part of medical practice. But even though it’s common, you might still feel nervous about a machine taking over for your heart and lungs. Share any questions and concerns with your provider. The more you learn about your surgery and the role of cardiopulmonary bypass, the more comfortable you may feel on the day of your surgery.
Last reviewed by a Cleveland Clinic medical professional on 08/31/2022.
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