Still, these antigens may become a factor in matching blood for a person who has had many transfusions in the past, as is the case for some people with cancer. These are rare because people don’t make antibodies against them unless they have had transfusions before. There are other antigens on red blood cells that can lead to transfusion reactions. Her anti-Rh antibodies can attack Rh-positive blood cells in the fetus.
If an Rh-negative woman makes antibodies like this, it can seriously harm any Rh-positive babies she may have in the future. This is because an Rh-positive blood transfusion can cause a person with Rh negative blood to make antibodies against the Rh factor, causing a transfusion reaction (discussed below). But people with Rh-negative blood should only get Rh-negative red blood cells except in extreme emergencies. If you have Rh-positive blood, you can get Rh-positive or Rh-negative red blood cell transfusions. A person who has type B, Rh-positive blood is called B positive, whereas a person with type B, Rh-negative blood is B negative.
Blood typesīlood types are important when it comes to transfusions. At that point, more blood tests must be done to find a donated blood component that closely matches the patient. If a transfusion is needed, it must be prescribed by a health care provider. Tests of clotting (coagulation) may also be done if abnormal bleeding is a problem. A CBC measures the levels of components within the blood such as red blood cells, white blood cells, and platelets. The amount and part of the blood transfused depends on what the patient needs.įirst, blood tests such as a complete blood count (CBC) are done to find out if the patient’s symptoms are likely to be helped by a transfusion. A blood transfusion is given through tubing connected to a needle or fine tube (catheter) that’s in a vein.