washed red blood cells

Medically Reviewed on 1/9/2023

Generic Name: washed red blood cells

Other Names: washed RBCs

Drug Class: Blood Components

What are washed red blood cells, and what are they used for?

Washed red blood cells are red blood cells separated from whole blood that undergo a washing process before transfusion. Red blood cells (RBCs), also known as erythrocytes, are cellular components of blood that give blood its characteristic red color. Red blood cells contain hemoglobin, an iron-rich protein that carries oxygen from the lungs to all the tissues, and carbon dioxide back to the lungs to be eliminated in exhalation.

Red blood cells are used for transfusion in patients who have insufficient tissue oxygen because of active bleeding or symptomatic anemia, to increase the red blood cell count, hemoglobin level, and consequently, blood’s oxygen carrying capacity. Washed red blood cells are used for transfusion in patients who have severe allergic reactions (anaphylactic) to standard red blood cell transfusions. Washing removes 98-99% of the plasma constituents that can cause anaphylactic reactions in some patients.

Red blood cells are separated by centrifugal process from whole blood collected from donors and screened for infectious diseases. The collected RBCs undergo additional centrifugation for 2 hours, which removes most of the plasma constituents, including some white cells and platelets, proteins, antibodies and electrolytes such as potassium. The washed RBCs are suspended in normal saline, saline with glucose, or an additive solution before transfusion. The shelf-life of washed RBCs is 4 hours at 20 to 24 degrees C or 24 hours if stored at 1 to 6 C.

Washing of red cells is performed only if it is clearly needed because it reduces the quality and quantity of the end product. Washed red blood cells are also matched for blood group (ABO) compatibility with the recipient before transfusion. Red blood cells used for transfusion in certain patients with special requirements may undergo other processes such as special filtering or irradiation to inactivate blood components such as leukocytes, before transfusion.

Uses of washed red blood cells include transfusion in patients with:

  • Recurrent severe allergic reactions to standard RBC transfusion
  • Immunoglobulin A (IgA) deficiency with anti-IgA antibodies when IgA deficient donor RBCs are not available, to prevent anaphylactic transfusion reaction
  • Risk for excessive increase in blood potassium levels (hyperkalemia)


  • Do not use red blood cell transfusion to treat anemia that can be corrected with non-transfusion treatments such as iron therapy, unless immediate correction is required.
  • Do not administer RBC transfusion to merely increase blood volume and/or oncotic pressure, or to improve wound healing or to provide a sense of wellbeing.
  • Washing RBCs reduces approximately 85% of the leukocytes and is not adequate for use in patients who require leukocyte-reduced RBCs. Only irradiated RBCs should be used to prevent transfusion-associated graft-versus-host disease (TA-GVHD).
  • Washing RBCs should be performed only when it is clearly needed, because it can take up to 2 hours and yield lower quality and quantity of RBCs. In addition, washing drastically reduces the shelf life and should be administered within a short time to prevent potential bacterial contamination and septic transfusion reactions.
  • All washed RBC transfusions must be given using blood administration sets containing 170- to 260-micron filters or 20- to 40-micron microaggregate filters, unless transfusion is given via a bedside leukocyte reduction filter.
  • No other medications or fluids other than normal saline should be simultaneously given through the same line as washed RBCs without prior consultation with the medical director of the blood bank.
  • Monitor patients for signs of transfusion reaction, including vital signs, before, during, and after transfusion. If transfusion reaction is suspected, stop the transfusion, assess and stabilize the patient, and notify the blood bank to initiate an investigation.
  • Monitor for iron overload due to hemoglobinopathies such as sickle cell disease or thalassemia in patients chronically transfused with RBCs.
  • RBC transfusions carry risk for non-septic infections including human immunodeficiency virus (HIV) hepatitis B and C viruses (HBV and HCV), human T-lymphotropic virus (HTLV), cytomegalovirus (CMV), West Nile virus (WNV), parvovirus B19, Lyme disease, babesiosis, malaria, Chagas disease and variant Creutzfeldt-Jakob disease (vCJD).
  • Consult with the blood bank medical director or a hematologist if you have questions regarding special transfusion requirements.


Sickle cell disease is named after a farming tool. See Answer

What are the side effects of washed red blood cells?

Common side effects of washed red blood cells include:

  • Hemolytic transfusion reactions that destroy red blood cells 
  • Feverish (febrile) non-hemolytic reactions
  • Post-transfusion bruising (purpura)
  • Transfusion-associated circulatory overload (TACO)
  • Transfusion-related acute lung injury (TRALI)
  • Allergic reactions such as:
  • Serious allergic (anaphylactic) reactions including:
    • Swelling under the skin and mucous membrane (angioedema)
    • Respiratory distress
    • Shock
  • Transfusion-transmitted infections and septic reactions
  • Transfusion-associated graft-versus-host disease (TA-GVHD)

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

What are the dosages of washed red blood cells?

Recurrent Severe Allergic Reactions to Red Cell Transfusions

  • 1 unit increase hemoglobin 1 g/dL in average sized adults without active bleeding or hemolysis; usually given over 1-2 hours but not longer than 4 hours
  • Rarely necessary to transfuse to hemoglobin over 10 g/dL
  • Actively bleeding patients dosing and rate of administration varies depending on rate of bleeding and must be evaluated on a case-by-case basis
  • Washed RBC units may not provide full 1 g/dL increase in hemoglobin per unit because 10-20% of the RBCs are lost in the washing process.

Other Indications and Uses

  • Recurrent severe allergic transfusion reactions such as anaphylaxis or severe urticarial reactions not prevented by pre-transfusion antihistamine and corticosteroid administration
  • Depletion of potassium and anticoagulants prior to transfusion to a fetus or to a neonate with renal failure or when large amount of RBC component needed for neonate (i.e., RBC exchange, dialysis, ECMO, etc.) when fresh RBCs are not available.
  • IgA deficiency with documented anti-IgA antibodies when IgA deficient donors are not available to prevent anaphylactic transfusion reactions
  • Atypical hemolytic-uremic syndrome (HUS) with T-antigen activation (controversial)
  • Recurrent febrile non-hemolytic transfusion reactions not prevented by leukocyte reduction and antipyretics
  • Consult with your blood bank medical director for questions regarding indications of washed blood products


  • 10-15 mL/kg increases hemoglobin 2-3 g/dL in patients without active bleeding or hemolysis
  • Actively bleeding patients dosing and rate of administration varies depending on rate of bleeding and must be evaluated on a case-by-case basis

What drugs interact with washed red blood cells?

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

  • Washed red blood cells have no known severe, serious, moderate, or mild interactions with other drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider about all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or healthcare provider if you have any questions about the medication.

Pregnancy and breastfeeding

  • Cytomegalovirus-seronegative or CMV reduced risk (leukocyte reduced) red blood cells should be used in pregnant or breast-feeding women who are CMV-seronegative or whose CMV status is unknown.

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Washed red blood cells are used for transfusion in patients who have severe allergic reactions (anaphylactic) to standard red blood cell transfusions. Common side effects of washed red blood cells include hemolytic transfusion reactions that destroy red blood cells, feverish (febrile) non-hemolytic reactions, post-transfusion bruising (purpura), transfusion-associated circulatory overload (TACO), transfusion-related acute lung injury (TRALI), allergic reactions, serious allergic (anaphylactic) reactions, and transfusion-transmitted infections and septic reactions.

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Medically Reviewed on 1/9/2023