A cardiovascular perfusionist is a healthcare professional, theoretically trained in general, pediatric, cardiac and thoracic surgery who operates the cardiopulmonary bypass during cardiac surgery and other surgeries that require cardiopulmonary bypass to manage the patient's physiological status. As an extremely crucial member of the cardiovascular surgical team, the perfusionist helps maintain blood flow to the body's tissues as well as regulate levels of oxygen and carbon dioxide in the blood, using a heart–lung machine.