Although all donors appear to be compatible in the post-transfusion crossmatch, they are not.

  • The results are false negatives - the patient's antibody has been "mopped up" by adsorbing to the incompatible transfused O Rh negative RBC.
  • Given that 6 donors were positive using the pretransfusion plasma, the antigen is higher frequency and most donors would be antigen-positive and incompatible.
  • The TS medical director should be consulted before any decision to transfuse is made.
  • Transfusing RBC before tests are complete requires physicians to sign an emergency release form in which they assume full responsibility.