Transfusion Workflow

This provides a general overview of the transfusion type and screen as well as further investigations and crossmatching workflow.

Specimen Integrity Checks

Checks for possibly discrepancies or issues affecting specimen quality and patient safety

• Correct number of tubes should be accounted for
• Labels must be fully visible without any cut-off information
• Name and MRN must match requisition
• Tubes must be initialed and dated by collector; this must match the requisition
• Sample must be <24h old
• Tube must be collected properly (adequate volume, correct tube type [EDTA])
  • Must not be clotted or grossly hemolyzed

Type & Screen

• Perform IS forward and reverse typing
  • Anti-A, Anti-B, Anti-D1, Anti-D2, Rh Control, A1 cell, B cell
  • Record reactions, reactions are expected to be 2+ or greater
  • Check for discrepancies and mixed fields
    • Discrepancies may include extra or missing reverse reactions
    • Mixed fields may appear as some grade of agglutination alongside a turbid/unclear background. Check microscopically to confirm (will see two populations, e.g., agglutinated cells and unagglutinated cells)
  • If there are discrepancies, attempt to correct them
    • Mixed field: check transfusion history in past 3 months that explains results
    • Extra/missing reactions: see below
• Perform gel screening

Rh Control

• Rh Control used when:
  • One reagent reacts but the other doesn't
  • IAT testing is needed for Weak D testing
  • Patient is AB Rh Positive (all forward grouping is positive - use control to check for agglutination)
    • Rh Control should be negative
• Causes of positive Rh control

Weak D Testing

Detect weaker expression of D antigen using IAT method

• Perform routine Anti-D1 and Anti-D2 (may cause sensitization)
  • Grade IS results
• Incubate both tubes 37°C, wash tubes (to remove unbound antibodies), and add AHG
• If sensitization occurs, AHG will cause agglutination
• Check Rh control is negative to verify validity of test
  • If positive, could be due to in vivo coating of cells with antibody (e.g., auto-antibodies, mother's antibody on fetal cells, antibody on donor cells, etc.)
• Confirm negatives by adding Coomb's Control Cells