The process in which donated blood is introduced into the blood-stream of a patient is called a blood transfusion. The recipient may receive whole blood, platelets, plasma or blood cells according to need. Transfusions of either whole blood or components of blood are given intravenously through an IV.
Before the procedure, the frozen donor blood will be thawed out, mixed with the a sample of the recipient blood and monitored for compatibility. The donor blood and the recipient blood must be compatible in order for the transfusion to be successful. The blood will be given in a slowly dripping IV over a period of up to two hours.
During the Transfusion
According to the University of Illinois Medical Center, most adverse reactions occur 15 minutes into the blood transfusion. Therefore, the recipient will be closely monitored by medical professionals for any symptoms associated with adverse reaction. Certain reactions might occur even if the blood products are compatible with each other. The most common reaction is hypersensitivity to the donated blood. Symptoms of hypersensitivity include itching, difficulty breathing and rash. If this happens, the transfusion will be stopped and the donor blood will be switched.
The recipient may also experience severe chills. This is a transient symptom due to the low temperature of the donor blood.
Immediately After Transfusion
If the patient receives mismatched blood, which is extremely rare, the recipient's immune system will attack the red blood cells in the donor blood. This is called an acute hemolytic reaction. Acute hemolytic reaction can be fatal in rare instances. Symptoms of acute hemolytic reaction usually begin immediately after the transfusion and can include anxiety attack, pallor, chest discomfort, severe back pain or difficult respiration. The doctor can diagnose a hemolytic reaction by testing the urine or blood for hemoglobin from the red blood cells that were destroyed. In the case of acute hemolytic reaction, the recipient will be given a diuretic such as Lasix and receive a hydrating IV to encourage the body to excrete the dead cells quickly.
Delayed hemolytic reaction is a rare possibility. This event is much less dangerous than acute hemolytic reaction because the red blood cells are destroyed more slowly, allowing the body time to produce more. Delayed hemolytic reaction usually produces no symptoms and often goes undiagnosed. Routine post-transfusion hemoglobin tests may reveal delayed hemolytic reaction. The onset of this reaction is between four and eight weeks post procedure, but it can be as late as one month. No intervention is required, unless the patient experiences fever. In this case, the fever should be treated symptomatically.