What Is a Heart Lung Machine?

A heart lung machine is a colloquial term for a medical procedure known as a cardiopulmonary bypass (CPB). A heart lung machine assumes the functions of the heart and lungs, which must sometimes be stopped during open-heart surgery to provide a stable platform during the operation.

Purpose of the Heart Lung Machine

• The heart lung machine assumes the functions of the heart and the lungs and continues the circulation and oxygenation of blood throughout the body. The patient would die quickly without the support of a heart lung machine.

How Does It Work?

• The heart lung machine uses polyvinyl chloride (PVC) tubing to divert blood through a mechanical pump. Another set of PVC tubing delivers blood to an oxygenator, or artificial lung. A cannula or catheter is used to connect the PVC tubing to the aorta and other parts of the heart.

Risks

• During the CPB, the blood of the patient is in contact with a foreign surface, and then recirculated through the body; the body may have a toxic reaction to this contact. Also, the kidneys may be particularly impacted by this procedure, leading to problems urinating or renal failure.

Atelectasis

• A condition known as atelectasis may occur. This is when the lungs fail to re inflate after the patient is off the lung machine.

Heart Lung Machine: First Use

• The first surgical use of a heart lung machine on a human occurred in 1953, when Dr. John H. Gibbon used the machine to perform surgery on a patient. The machine assumed all the circulatory and respiratory functions for 26 minutes.