Hi and best wishes for a happy new year! This is my first post, but I am a little troubled by something that occurred in our hospital transfusion service, so I thought I should check with others. Patient background: Hx of a strong cold agglutinin that causes an ABO discrepancy. The patient forward types as B+ and reverses as Group O. According to the reference lab report, the ABO discrepancy could not be resolved by any of the techniques that were used. The transfusion recommendation is to crossmatch for compatibility with group O positive RBCs. The patient is frequently transfused on an outpatient basis. The antibody screen is consistently negative with Ortho gel, but a comment in the patient notes says to use prewarm technique. I'm not sure why the note is there, but I've used both methods.) Recently I found a crossmatch requistion for this patient in the in-basket at the start of my shift. The patient specimen was nowhere to be found. A few hours later, my BB partner wondered aloud if the specimen was in the incubator. "What incubator?" I asked. As it turned out, the sample had been sitting in a 37 deg. C incubator in a different lab section for over 3 hours -- and its stay was actually longer, because my partner didn't remove the specimen from the incubator for another 3 hours. My thought was that the specimen had been compromised by this incubation and should not be used for antibody testing or crossmatch purposes. Such incubation is not part of our prewarm procedure or part of any other procedure that we have, so I left a note for the day shift to have the patient sample redrawn. I later learned that my request was overruled, the specimen was tested the following day, and units were crossmatched. The transfusion was later canceled for unrelated reasons. If prewarm technique carries some risk of missing allo-antibodies, wouldn't prewarming the entire specimen for antibody screening/compatibility testing carry as much or even more risk? I have never heard of doing this, although an SBB friend tells me that there are special techniques where that is done.
