Cardiopulmonary bypass is a medical procedure used during cardiac surgery to divert blood from the heart and lungs to an artificial pump, allowing surgery on the heart itself. The word "cardiopulmonary" refers to the heart and lungs, while "bypass" means to redirect blood flow. The word is spelled /ˌkɑrdioʊˈpʊlmənɛri ˈbaɪpæs/ in IPA phonetic transcription, with stress on the second syllable of "cardio" and the first syllable of "pulmonary." The "p" sound is silent in the final syllable of "pulmonary."
Cardiopulmonary bypass, commonly referred to as CPB, is a medical procedure that allows the diversion of blood flow away from the heart and lungs during certain types of surgeries. It involves the use of a heart-lung machine, also known as a bypass machine, which takes over the functions of the heart and lungs temporarily.
During CPB, the patient's blood is rerouted through the machine, where it is oxygenated, purified, and returned to the body, effectively bypassing the heart and lungs. This allows surgeons to perform complex procedures on these organs while maintaining a stable blood flow and oxygenation.
Cardiopulmonary bypass is commonly used in open-heart surgeries, such as coronary artery bypass grafting and valve replacements. By temporarily halting the heart's pumping action and diverting blood flow, surgeons gain a clear surgical field and can perform delicate procedures with precision.
The bypass machine consists of a heart-lung pump, a blood reservoir, and an oxygenator. It closely monitors and adjusts the patient's blood temperature, pressure, and volume. Additionally, the machine may be equipped with filters to remove air bubbles, micro-emboli, or other contaminants from the blood.
Although cardiopulmonary bypass is critical in supporting the life of a patient during complex heart surgeries, it does pose certain risks. These include potential damage to blood cells, activation of the inflammatory response, and the potential for clot formation. However, advancements in technology and techniques aim to minimize these risks and improve patient outcomes during CPB.
The word "cardiopulmonary" originates from the combination of two Greek words: "cardio" meaning "heart" and "pulmonary" meaning "relating to the lungs". These words were derived from the Greek roots "kardia" and "pulmo" respectively.
The term "bypass" comes from the Middle English word "bipassen", which means "to go around". It was formed by combining the prefix "bi-" (indicating "around" or "on both sides") and the word "passen" (meaning "to go or move"). "Bypass" has been used in English since the 19th century to describe the act of circumventing or avoiding something.