What are the potential adverse effects of a blood transfusion?

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Last updated: May 15, 2025View editorial policy

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From the Guidelines

Blood transfusions can cause several side effects, including fever, allergic reactions, fluid overload, transfusion-related acute lung injury (TRALI), hemolytic reactions, iron overload, and infections, with the risk of fatal hemolysis estimated to be 1:1,250,000 or 8 per 10 million red blood cell units 1.

Common Side Effects

  • Fever (febrile nonhemolytic transfusion reactions) was estimated to be 1.1% with prestorage leukoreduction and 2.15% with poststorage leukoreduction 1
  • Allergic reactions, which can range from mild itching to severe anaphylaxis requiring immediate medical attention
  • Fluid overload may occur, especially in patients with heart or kidney problems, causing shortness of breath and swelling, with an estimated risk of 4% for transfusion-associated circulatory overload (TACO) 1

Serious Complications

  • Transfusion-related acute lung injury (TRALI) is a serious complication causing breathing difficulties and low oxygen levels
  • Hemolytic reactions when the immune system attacks transfused red blood cells, causing fever, pain, and kidney damage, with an estimated risk of fatal hemolysis of 1:1,250,000 or 8 per 10 million red blood cell units 1
  • Iron overload can develop in patients receiving multiple transfusions over time
  • Infections, though rare due to rigorous blood screening, remain a potential risk
  • Delayed hemolytic reactions can occur days to weeks after transfusion

Management and Monitoring

These side effects occur because transfusions introduce foreign biological material into the recipient's body, potentially triggering immune responses or causing circulatory system stress. Most transfusion reactions are manageable when identified promptly, which is why patients are closely monitored during and after receiving blood products 1.

From the Research

Types of Side Effects

  • Acute adverse reactions to transfusion occur within 24 hours and include:
    • Acute hemolytic transfusion reaction
    • Febrile nonhemolytic transfusion reaction
    • Allergic and anaphylactic reactions
    • Transfusion-related acute lung injury
    • Transfusion-related infection or sepsis
    • Transfusion-associated circulatory overload 2
  • Delayed transfusion adverse reactions develop 48 hours or more after transfusion and include:
    • Erythrocyte and platelet alloimmunization
    • Delayed hemolytic transfusion reactions
    • Posttransfusion purpura
    • Transfusion-related immunomodulation
    • Transfusion-associated graft versus host disease
    • Iron overload with long-term transfusion 2

Symptoms and Management

  • Symptoms of transfusion reactions are often overlapping and nonspecific 3
  • When a reaction is suspected, it is critical to stop the transfusion immediately and report the reaction to the blood bank 3
  • New evidence-based algorithms of transfusion, newer blood screening methods and donor policies and deferrals, new laboratory testing, electronic verification systems, and improved hemovigilance can lead to the avoidance of unnecessary transfusions and decrease the incidence of serious transfusion reactions 3

Classification of Complications

  • All noninfectious complications of transfusion are classified as noninfectious serious hazards of transfusion 4
  • Acute complications occur within minutes to 24 hours of the transfusion, whereas delayed complications may develop days, months, or even years later 4

Prevention of Reactions

  • Clinical strategies may reduce the likelihood of reactions and improve patient outcomes 2
  • The use of acetaminophen and diphenhydramine premedication before blood component transfusions has been questioned, as they have failed to prevent transfusion reactions and have potential toxicity 5, 6

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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