Cardiopulmonary bypass is a medical technique used during cardiac surgery to temporarily take over the function of the heart and lungs. During the procedure, the patient's blood is rerouted through a machine that removes carbon dioxide, adds oxygen, and pumps the blood back into the body. This allows the surgeon to perform the necessary procedures on the heart while the patient's blood continues to circulate throughout the body. Cardiopulmonary bypass is a critical component of many cardiac surgeries and has greatly improved the success rates of these procedures.