Emergency blood transfusions have many benefits and can be lifesaving. But they also have a few risks. If you have an emergency transfusion, you may need to be watched for a reaction or other problems.
Some people may have a reaction to the new blood, such as a fever or breathing problems. They could also have an allergic reaction, like hives or swelling. Severe reactions are rare.
Sometimes people get an infection at the transfusion site. This can cause redness, swelling, pain, bleeding, or pus. Your doctor will tell you how to care for the site, if needed.
An infection from the new blood may also happen, but it’s rare. The U.S. Food and Drug Administration (FDA) enforces strict guidelines on the collection, testing, storage, and use of blood.
If you get blood that doesn’t match your blood type, this may also lead to problems. An example of this is getting an emergency transfusion of O-positive blood when you have an Rh-negative blood type, such as A-negative, B-negative, AB-negative, or O-negative.
When a person who is Rh-negative receives Rh-positive blood, their immune system may make antibodies. This response is called Rh sensitization. It may cause a harmful reaction during a future blood transfusion of Rh-positive blood. And in some cases it can affect the health of future pregnancies.
If you are Rh-negative and receive Rh-positive blood, you can be tested for Rh antibodies. If these antibodies are found, you will receive follow-up counseling from your doctor and care team. They can answer any questions you may have. They can let you know how to manage future blood transfusions. They also can help you plan for future pregnancies, if needed.