MINIMUM STANDARDS FOR INVESTIGATION OF TRANSFUSION RELATED ADVERSE REACTIONS

This document has been developed by SHOT, in the absence of a definitive guideline, and is intended to provide a checklist of investigations to support the differential diagnosis and assessment of transfusion related adverse reactions.  The standards are endorsed by the Transfusion Taskforce of the British Committee for Standards in Haematology, and it will be expected that, when reactions are reported to SHOT and to MHRA, the following investigations will have been carried out, as a minimum.

All severe transfusion reactions must be reported immediately to the hospital transfusion laboratory and the implicated blood pack returned to them.

Acute haemolytic transfusion reaction

Definition:
Fever and other symptoms/signs of haemolysis within 24 hours of transfusion. Confirmed by a fall in Hb, rise in LDH, positive  DAT and positive crossmatch.

Investigations:
Check correct identification of patient, blood unit and laboratory samples.
Repeat blood group determination, antibody screen, DAT, cross-match using pre-and post transfusion samples
Look for evidence of increased red cell destruction; fall in Hb, rise in LDH, bilirubin (LFTs) Hburia
Look for evidence of disseminated intravascular coagulation; coagulation screen including fibrinogen level and thrombin time, FDPs or equivalent.
Assess renal function; U&E,  creatinine
Urinalysis
Blood cultures to exclude bacterial contamination.

Delayed transfusion reaction

Definition:
Fever and other symptoms/signs of haemolysis more than 24 hours after transfusion. Confirmed by fall in Hb, rise in bilirubin, positive DAT and positive crossmatch not detectable pre-transfusion. Simple serological reactions (development of antibody without pos DAT or evidence of haemolysis) are excluded.

Investigations:
Antibody screen, DAT, cross-match using pre-and post transfusion samples if available. Consider refer to reference lab.
Look for evidence of increased red cell destruction; fall in Hb, rise in LDH, bilirubin

 Anaphylactic/severe allergic reaction

Definitions:
Anaphylactic reaction: Hypotension with one or more of: rash, dyspnoea, stridor, wheezing, angioedema, pruritus, urticaria, during or within 24 hrs of transfusion.

Severe allergic reaction: A severe allergic reaction with immediate risk to life occuring during or within 24 hours of transfusion, characterised by bronchospasm causing hypoxia, or angioedema causing respiratory distress .

Investigations:
If patient is dyspnoeic, CXR to exclude TRALI
Blood gases if patient is clinically hypoxic
IgA level and anti-IgA
Mast-cell tryptase, if available, can be useful in differentiating anaphylactic from allergic reactions.

Transfusion related acute lung injury (TRALI)

Definition:
Acute dyspnoea with hypoxia and bilateral pulmonary infiltrates during or within 6 hrs of transfusion, not due to circulatory overload or other likely cause.

Clinical criteria:
Evidence of hypoxaemia
Where possible, exclusion of left atrial hypertension
Bilateral lung infiltrates on CXR

Laboratory investigations:
Investigation of donor HLA and HNA antibody status
Finding of cognate antigen in patient
Lymphocytotoxic crossmatch and granulocyte crossmatch if patient sample available

Post-transfusion purpura

Definition:
Thrombocytopenia within 12 days after transfusion of red cells, associated with presence in patient of antibodies directed against the HPA systems.

Investigations:
Platelet count
Coagulation screen to exclude DIC as a cause of thrombocytopenia
HPA typing and HPA antibodies

Suspected transfusion transmitted bacterial infection

Investigations:
Blood culture
Bacterial investigation of the implicated pack according to blood service guidelines