Blood clotting abnormalities or problems that happen during surgery ? even minor surgery ? are serious because of the possibility of serious bleeding that cannot be stopped. The current standard practice for people with clotting abnormalities is to transfuse additional blood before the surgery, in an effort to decrease bleeding problems. However, transfusing blood before the surgery is not very effective in decreasing bleeding complications. In addition, it may be associated with other complications, including fluid buildup and swelling in the lungs. For this study, a person with a mild clotting problem is defined as one with an INR (International Normalized Ratio) between 1.5 and 3. Severe clotting is defined as an INR greater than 3. This study will aim to test if limiting or restricting transfusion for those patients with severe clotting problems (an INR greater than 3) will result in fewer transfusion problems and fewer unnecessary transfusions in comparison with the current, more liberal, transfusion use for all patients with both mild and severe clotting problems (an INR greater than 1.5).The investigators will also determine if liberal blood transfusion decreases the risk of bleeding after surgical procedures.