Complications of Blood Transfusion

Blood transfusions most often occur during or after surgery, but you might also require one following an injury, or if you suffer from an inherited blood disorder or from cancer. The transfusion involves directly adding donated blood, or a blood component, to another person through an intravenous line. Blood is made up of several parts: red blood cells, which carry oxygen to tissues or organs; platelets, which promote blood clotting; plasma, which carries blood cells throughout the body and contains proteins essential for blood clotting; white blood cells, which fight infection; and cryoprecipitate, which is another component essential for blood clotting. Blood can be separated into any of these individual components, so any or all of these might be included in a transfusion. According to the National Institutes of Health, about 5 million Americans each year need a blood transfusion. Most transfusions are successful and can often save lives. Sometimes, minor complications occur, and in rare instances, serious complications result.

Blood Type Incompatibility

• Every person has a blood type (categorized as A, B, AB or O) and must be matched to donor blood of the same type. In addition, people have an RH factor (either positive or negative) and certain antigens that must be deemed compatible with a donor's blood before a transfusion is given. In some cases, a person's antibodies reject donor blood during a transfusion. Often this is due to basic human error, when a provider gives a patient an incompatible blood type. When this happens, a conscious patient may display symptoms such as chills, fever, nausea, chest pain and flank pain. If a patient is unconscious, he may experience a rise in temperature, unexplained rapid heart rate, a drop in blood pressure, seeping at the surgical wound site, shock and kidney failure. These reactions are life-threatening but occur in only about 1 in 25,000 people. Incompatibility involving the RH factor results in less acute reactions that may not appear for months. A general feeling of unwellness, jaundice, fever, a fall in red blood cell counts and an increase in liver enzymes may all result. After diagnosis, medical support is given to the patient to treat symptoms, but these cases usually resolve themselves. Occurrence is approximately 1 in 2500.

Other Reactions

• About 1% to 3% of patients experience a fever after a blood transfusion. Hives and itching, without an elevation of temperature, also occur fairly often, in about 1% of patients. In very rare instances, a patient might experience a life-threatening allergic reaction to the donor's white blood cells, called anaphylaxis. Another very rare complication, pulmonary edema or fluid accumulation in the lungs, may occur. Both of these complications happen in less than 1 in 150,000 cases. In immunocompromised patients (such as those with HIV or leukemia), graft-versus-host disease can result from a blood transfusion. Graft-versus-host disease manifests when a recipient's white blood cells develop an immune response against the white blood cells in the donor blood. If a patient is known to have a compromised immune system, the donor blood can be irradiated to eradicate the offending cells.

Transmission of Infection

• A number of infectious diseases may be passed through the blood supply. When donating blood, participants must answer questions about their potential risk factors and health history. In addition, United States blood banks test all donated blood for HIV, Hepatitis B and C, HTLV-1 and 2, West Nile virus, and Treponema pallidum. Labs discard any blood with a positive screen for these diseases, so it never enters the blood supply. If you receive a blood transfusion in an undeveloped country, possibility of infection from any of these diseases is greater as screening is not as strict.

Possibility of Immune Suppression

• Some evidence exists that a person's immune system becomes suppressed as a result of a blood transfusion. In some patients, scientists observed a decrease in the number of cells that promote immunity (particularly killer T-cells). The medical community is unsure of the reason for this reaction and is equally unsure of all the medical implications. It might increase the likelihood of a recurrence of cancer in some patients and might also increase the risk of infection after surgery.

Massive Transfusions

• In extreme cases, a person might need a massive transfusion of blood---defined as 50% or more of total blood volume in 12 to 24 hours. Because of the enormity of the blood loss and donor volume, serious complications may arise, including problems with blood clotting, calcium binding, hypothermia, an imbalance in the acid and base components of the blood, and an increase in serum potassium. All of these complications can adversely affect major organ functions and can be life-threatening.

Plan Ahead

• If you know you are going in for surgery and will possibly need a transfusion, it is possible to donate your own blood to be used. If you are unable to donate your own blood, directed donations from a family member may also be preferred. Blood transfusions save lives, but as with any medical procedure, risks exist. Your doctor and medical support staff will always do their best to prevent complications and to mitigate any that might occur.