• In emergencies, there may be insufficient time for full ABO/Rh grouping and antibody screens.
  • Policies must be in place to allow for urgent (often manual and abbreviated) testing.
  • If testing is done manually, controls must be set up appropriately in parallel.
    • In particular, if a patient is typed as AB positive, controls must be checked to ensure they are negative – this is to avoid interference from cold agglutinins giving the wrong ABO blood group.
  • There must be processes in place for recall of blood products when discrepancies have been identified post-issue.
  • In an emergency, blood can be released without an antibody screen, but this must always be performed retrospectively to ensure that the issued unit is compatible with the recipient.
    • A serological crossmatch is not an appropriate substitute for an antibody screen.
  • At a minimum, the following must be done after a rapid group, before issuing group-specific red cells:
    • A reverse group using a different aliquot from the patient’s sample.
    • A repeat forward group using a different aliquot from the patient’s sample, with parallel controls.
    • A saline spin crossmatch.
  • Until the criteria above have been met, group O negative red cells must be used.
  • For large volume transfusion, use group O positive for women over 50 and men over 18 to preserve stocks of O negative blood, provided they have no detectable anti-D.
  • An order of preference for blood selection should be established. The following is suggested:
    1. ABO compatibility.
    2. Blood that is antigen negative for currently-detectable antibodies reactive by IAT at 37°C.
    3. Blood that is antigen negative for antibodies detectable by enzyme technique only.
    4. Blood that is RhD compatible (women of childbearing potential and patients <18 years only).
    5. Blood that is negative for any historical, but currently undetectable antibodies.
    6. Blood that is Rh- and Kell-antigen matched with the recipient, if chronic transfusion is anticipated.
    7. If fully-compatible blood is not available, the following priority of antigens should be followed (based on reports of reactions to incompatible transfusions): D>c>C>E>e>K>(k)>Jka/Jkb>Fya/Fyb>S/s/U>M>N>other high frequency antigens.
    8. If antigen-negative blood is not available, and time allows, there may be some benefit in selecting units heterozygous for the antigen rather than those that are homozygous for it.
  • If incompatible blood has to be supplied, the most senior transfusion scientist and the NHSBT consultant must be notified. They should liase with the Haematology consultant for the patient to be reviewed. Additional measures include:
    • The patient should be informed about the risk of haemolysis and the risk of not transfusing.
    • Ensure adequate hydration and monitoring of intake/output.
    • Baseline and serial monitoring for haemolysis.
    • Pre-medicate transfusions with 1g methylprednisolone IV. 
    • Transfuse with extra caution – sequential transfusion of 20ml > 50 ml > the remaining pack at the slowest rate consistent with the clinical condition, with close monitoring of vital signs.
    • Transfusion should ideally take place during working hours.
    • Some studies have shown that IVIG and steroids may correct anaemia in SCD patients with life-threatening DHTRs. Premedication with IVIG is not routinely required.