Specimen Collection
Specimen Requirements
A specimen is always required for pretransfusion testing for red cell components, except in emergencies (see Emergency Transfusion).
- If the patient has been transfused or pregnant within the past three months or the transfusion history is unknown, the blood specimen must be collected and tested within 96 hours of the anticipated transfusion.
- If the patient has not been transfused or pregnant in the past three months, specimens may be stored for longer periods. Each transfusion service will have a policy for this circumstance.
Specimen type and volume are variable depending on specific hospital policies and methodology. Historically, red top vacutainers were used for pretransfusion testing but today many hospitals use only EDTA specimens. Serum separation tubes (SST) or gel separation tubes used in other areas of the clinical laboratory are not used for pretransfusion testing.
Specimen collection is usually not required from patients who require Plasma, Platelet or Cryoprecipitated AHF components if there is ABO/Rh testing done on a current admission.
The patient's ABO group is required in order to give compatible blood components. Depending on hospital requirements, a patient specimen may be required upon each new admission to confirm the patient's ABO.
Critical Aspects of Specimen Collection
Patient identification
Specimen labelling
Specimen Retention Requirements
Provincial standards apply to specimen retention. Retention of both patient and donor unit are required.
- A sample of red cells from each unit and recipient specimens should be retained for a minimum of 7 days post-transfusion in case a transfusion reaction investigation is required.
- Many hospitals store a segment of all incoming RBC units for 49 days. This ensures the maximum shelf life of the unit (42 days) plus 7 days.