<P> CPB mechanically circulates and oxygenates blood for the body while bypassing the heart and lungs . It uses a heart -- lung machine to maintain perfusion to other body organs and tissues while the surgeon works in a bloodless surgical field . The surgeon places a cannula in right atrium , vena cava , or femoral vein to withdraw blood from the body . The cannula is connected to tubing filled with isotonic crystalloid solution . Venous blood that is removed from the body by the cannula is filtered , cooled or warmed , oxygenated , and then returned to the body . The cannula used to return oxygenated blood is usually inserted in the ascending aorta , but it may be inserted in the femoral artery . The patient is administered heparin to prevent clotting , and protamine sulfate is given after to reverse effects of heparin . During the procedure , hypothermia may be maintained ; body temperature is usually kept at 28 ° C to 32 ° C ( 82.4 -- 89.6 ° F ) . The blood is cooled during CPB and returned to the body . The cooled blood slows the body 's basal metabolic rate , decreasing its demand for oxygen . Cooled blood usually has a higher viscosity , but the crystalloid solution used to prime the bypass tubing dilutes the blood . </P>
<P> CPB mechanically circulates and oxygenates blood for the body while bypassing the heart and lungs . It uses a heart -- lung machine to maintain perfusion to other body organs and tissues while the surgeon works in a bloodless surgical field . The surgeon places a cannula in right atrium , vena cava , or femoral vein to withdraw blood from the body . The cannula is connected to tubing filled with isotonic crystalloid solution . Venous blood that is removed from the body by the cannula is filtered , cooled or warmed , oxygenated , and then returned to the body . The cannula used to return oxygenated blood is usually inserted in the ascending aorta , but it may be inserted in the femoral artery . The patient is administered heparin to prevent clotting , and protamine sulfate is given after to reverse effects of heparin . During the procedure , hypothermia may be maintained ; body temperature is usually kept at 28 ° C to 32 ° C ( 82.4 -- 89.6 ° F ) . The blood is cooled during CPB and returned to the body . The cooled blood slows the body 's basal metabolic rate , decreasing its demand for oxygen . Cooled blood usually has a higher viscosity , but the crystalloid solution used to prime the bypass tubing dilutes the blood . </P>
where are the cannula most commonly placed for cardiopulmonary bypass procedures
where are the cannula most commonly placed for cardiopulmonary bypass procedures
ascending aorta
ascending aorta