What is a Blood Transfusion?

Blood is usually collected from voluntary blood donors. Donated blood undergoes extensive checking and testing to prevent the transmission of blood-borne infections through the transfusion of contaminated blood. Common infections that may be transmitted in this manner include HIV and Hepatitis B and C.

Risks associated with blood transfusion

Blood transfusion is associated with several risks. In the past, the transmission of infections was one of the most important risk factors associated with blood transfusion. Nowadays, this risk is much smaller due to stringent blood screening processes. Other risk factors associated with blood transfusion include:

• An allergic reaction to the blood may occur. These reactions range in severity from a mild skin reaction or fever, for example, through to more severe and life threatening reactions
• A severe allergic reaction may occur as a result of mismatched transfusion due to ABO or Rh incompatibility, for example. Blood is typed into 4 major groups: A, B, O and AB. In cases of ABO incompatibility, the reaction is invariably severe and leads to destruction of circulating donor RBCs, respiratory collapse and acute renal failure.
• Transfusion associated circulatory overload (TACO)
• Transfusion associated lung injury (TRALI)
• Over time, repeated blood transfusions may cause iron overload that leads to iron deposition in the tissues and organ injury.