There are several different components of the blood that can be transfused into an adult. Red blood cells are the most common type of blood product transfusion. If a health care provider has decided that a patient might need a transfusion of blood, or blood products, he or she will explain the reasons for the transfusion. There are several reasons why a patient may require a blood transfusion, including the following:
- A sudden loss of blood because of trauma.
- An anticipated or actual loss of blood during surgery.
- Low hemoglobin before, during, or after surgery.
- Severe heart, lung, liver, or kidney disease.
- Bone marrow failure.
- Moderate to severe anemia.
Blood donated by volunteers is collected and stored in sterile bags. The bags are used once and then thrown away. Before blood is given to the patient, it is crossmatched by blood type with the patient’s own blood to make sure it is compatible. While all blood is made of the same basic elements, the presence of absence of certain substances determines a specific blood type.
The blood will be given through a needle or catheter placed in the vein. The patient’s temperature, blood pressure, and heart rate will be checked many times while the blood is being given. It may take a few hours to complete the process.