Definition
A Haemolytic Transfusion Reaction (HTR) occurs when antibodies in the patient’s plasma react with antigens on transfused allogeneic red blood cells, causing haemolysis.
Symptoms include fever, rigors, chills, hypotension, pain, dyspnoea, tachycardia, nausea, or restlessness; acute HTR can be life-threatening.
Acute haemolytic transfusion reactions (AHTR) occur during or within 24 hours of transfusion.
Delayed haemolytic transfusion reactions (DHTR) occur more than 24 hours following a transfusion (may occur days or weeks after a transfusion).
Hyperhaemolysis is a severe subtype of DHTR predominantly seen in patients with sickle cell disease and characterised by the destruction both of transfused donor red cells and the patient's own red cells.
Frequency
Rare (≥1/10,000 to < 1/1,000).
Patients with haemoglobinopathies (in particular patients with sickle cell disease) are at a higher risk of HTR.
Reducing the risk
Patients are encouraged to report any unusual sensation experienced during or after their transfusion. They should also be discharged with information about signs/symptoms to look out for and who to contact.
Patients with a history of HTRs are at higher risk of recurrence and further transfusion must be carefully considered and specialist advice sought.
Historical red cell antibodies should be clearly documented in clinical notes and transfusion records including the transfusion laboratory information system, and compatible blood should be issued. Where patients have complex blood requirements, the transfusion plan should clearly define blood availability and use.
Patients who have red cell antibodies should be informed of this and encouraged to alert healthcare professionals to this in future if transfusion is planned.
Further information/ resources
SHOT Haemolytic Transfusion Reactions (HTR) Cumulative Data
SHOT HTR Webinar 2021
SHOT Bite No.14: Transfusion Errors and Reactions in Patients with Haemoglobinopathies
SHOT Bite No.15: Hyperhaemolysis
SHOT Bite No. 31: The role of Sp-ICE in preventing Haemolytic Transfusion Reactions
BSH Guideline on the Investigation and Management of Acute Transfusion Reactions (2023)