Acute haemolytic transfusion reaction

This occurs during or within the first 24 hours of a blood transfusion.

When to suspect this adverse reaction?

It characteristically begins with an increase in temperature and pulse rate.

Symptoms may include chills, rigors, dyspnoea, chest and/or flank pain, discomfort at infusion site, sense of dread, abnormal bleeding and may progress rapidly to shock.

Patients may develop oliguria, haemoglobinuria and haemoglobinaemia.

In anaesthetised patients, hypotension and evidence of disseminated intravascular coagulation (DIC) may be the first sign. This may be a fatal reaction.

Usual causes?

Acute haemolytic transfusion reactions can be both immune mediated or nonimmune mediated.

Immune mediated reactions may be associated with:

  • ABO/Rh mismatch
  • Red cell alloantibodies (non-ABO) as a result of patient immunisation from previous pregnancy or transfusion.(1)
  • Rare cases when Group O donor platelets with high titres of anti-A and/or anti-B are transfused to a non-Group O recipient.(1)

Transfused red cells are destroyed, due to incompatibility of antigen on transfused cells with antibody in the recipient circulation.

The most common cause is transfusion of ABO/Rh incompatible blood due to clerical errors or patient identification errors such as improper labelling of samples, administering blood to the wrong patient or testing errors.(1) As little as 10 mL of incompatible blood can produce symptoms of an acute haemolytic reaction (2). ABO/Rh incompatibility occurs in about 1:40 000 transfusions.(2)

This may also occur in the presence of non-ABO red cell alloantibodies in the patient’s plasma which have not been previously identified. Occasionally a patient may have an antibody at levels below the detection capabilities of the antibody screening method or a clerical error occurs in the labelling of patient samples. Rarely is it caused by emergency uncrossmatched blood being given to an alloimmunised patient.


Clinically assess patients for common features of haemolysis occurring within 24 hours of transfusion.

Check clerical records, such as ABO typing of patient and unit.

Repeat patient ABO grouping and antibody screen in both pre- and post-transfusion samples.

Perform Direct Antiglobulin Test (DAT) and Indirect Antiglobulin Test (IAT), renal function, and tests for haemolysis (eg serum haptoglobulin).

What to do?

Stop transfusion immediately and follow other steps for managing suspected transfusion reactions.

Seek urgent medical assistance.

Maintain blood pressure and renal output.

Induce diuresis with intravenous fluids and diuretics.

This may become a medical emergency so support blood pressure and maintain an open airway.

Do not administer additional blood packs until cleared by haematologist or Transfusion Service Provider.

  1. Callum JL, Lin Y, Pinkerton PH, Karkouti K, Pendergrast JM, Robitaile N et al. Chapter 5, Transfusion Reactions. Bloody Easy 3: Blood Transfusions, Blood Alternatives and Transfusion Reactions: A Guide to Transfusion Medicine, 3rd edition. Canada: Ontario Regional Blood Coordinating Network, 2011. [cited 2012 Sep 13]. Available from:
  2. Fung MK (ed). Non-infectious complications of blood transfusion. Chapter 27, AABB Technical Manual, 18th edition. AABB, Bethesda, 2014.