Blood transfusion risks range from mild to severe reactions. Some occur infrequently, while others are more common. Some occur within minutes, and others can take weeks to manifest. Risks depend, in part, on the blood product being transfused. Blood products are the various components harvested from fresh whole blood and spun down, separated, washed or filtered to isolate certain elements of what makes up the blood--platelets, plasma, white blood cells, immune globulins and packed red blood cells. Since the symptoms of each reaction can overlap somewhat, transfusions are typically stopped until the exact cause of the reaction is known. Symptoms associated with transfusion reactions may include chills, fever, anxiety, lightheadedness, facial flushing, itching, urticarial rash, low back or flank pain and shortness of breath.
Nonhemolytic Febrile Reaction
Hemolysis is a breakdown of the red blood cells; therefore, a nonhemolytic febrile reaction consists of a fever without accompanying red cell destruction. Nonhemolytic reactions themselves are self-limiting and benign and can occur during or just after a transfusion. According to the FDA's Circular of Information, the risk of this type of reaction is approximately 1 percent. It is more common in pregnant females and those with a history of previous transfusions. An antipyretic medication such as acetaminophen to control the fever is usually all that is required to treat this.
Allergic Reactions
An allergic reaction to a blood product is similar to an allergic response to a medication or particular food. A mild case can include itching, an urticarial skin rash, swelling of the lips or eyes and nausea, vomiting or diarrhea. More severe allergy can turn into full blown anaphylaxis--cough, wheeze and acute shortness of breath. A drop in blood pressure with an increased heart rate can also appear. An antihistamine such as diphenhydramine (Benadryl) or a corticosteroid are used to mitigate most mild to moderate allergic responses. For anaphylaxis, epinephrine and intravenous fluids may be necessary.
Acute Hemolytic Transfusion Reaction
Generally more severe than nonhemolytic febrile reactions, acute hemolytic febrile reactions occur when red blood cells are actually destroyed, releasing their contents into the bloodstream and on to the organs of the body. Some of these released chemicals can affect liver and kidney function, manifesting as jaundice (yellowing of the skin) and decreased urine output or a discoloration of the urine.
Delayed Hemolytic Transfusion Reaction
Because some people will only mount a mild response to a previous transfusion; a reaction from a subsequent transfusion could be delayed several weeks. Some people will not even show any symptoms, while others may have a slight fever. Lab work may reveal evidence of red blood cell destruction, but consequences are typically mild.
Transfusion-Related Acute Lung Injury
Transfusion-related acute lung injury is a rare but potentially fatal blood transfusion risk that can cause severe shortness of breath, low blood pressure and a characteristic pattern on a chest X-ray within hours of the transfusion. Close observation is required, and treatment usually involves supplemental oxygen and respiratory support.
Graft Versus Host Disease
This is a serious and often fatal reaction where lymphocytes--a type of infection-fighting cell--from the donor incorporate themselves into the recipient and slowly attack the recipient's own tissues. This can take up to a month after the transfusion to appear and is more common in immune-compromised recipients.
Infection Risks
Infectious organisms can be transferred during a blood transfusion. While bacterial infections are overall quite rare, Yersinia species and syphilis, as well as a few other organisms, can potentially be transmitted. Viral transmission includes the human immunodeficiency virus (HIV) as well as hepatitis B and C viruses, human T-lymphotropic virus (HTLV-1 and HTLV-2) and cytomegalovirus (CMV). There also exists a theoretical possibility of transmission of the prion linked to Creutzfeldt-Jakob Disease (CJD). Malaria is an additional risk.
Other Risks
Other risks include the potential for wash-out (or dilution) of a person's own blood because of massive transfusion of donor blood with less effective platelets. This can cause increased bleeding of small cuts or significant bruising. Another risk is heart failure from an overload of volume to the vasculature. Because transfused blood products can draw fluid out of the cells, a higher volume of fluid courses through the vessels. In someone with an underlying heart condition or kidney problem, this can lead to heart failure--an inability of the heart to effectively pump this increased volume of blood. Iron overload is another risk. Rarely, hypothermia can occur from large transfusions of inadequately warmed blood products. Those with underlying kidney or liver conditions may be susceptible to certain electrolyte imbalances after a blood transfusion.
References
- The Merck Manuals Online Medical Library: Complications of Transfusion
- National Heart Lung and Blood Institute: What Are the Risks of a Blood Transfusion
- American Cancer Society: Possible Risks of Blood Product Transfusions
- U.S. Food and Drug Administration: Transfusion Related Acute Lung Injury (TRALI)
- U.S. Food and Drug Administration: Circular of Information
