If you are having open heart surgery what happens to your blood?

The duration depends on the complexity of the procedure. The patient is put under anesthesia and is unconscious during the surgery. Don't worry about it, you will feel no pain during the surgery, and afterwards you will be on painkillers. The surgeons are skilled professionals who have performed the operation hundreds of times; you are in good hands. http://heart-disease.emedtv.com/open-heart-surgery/open-heart-surgery.html