I am LOINC mapping a group of Blood Bank tests where the actual blood product requested in a crossmatch is a separate result/observation that is a part of the patient record.(unit # is typed in). I believe that I could use 936-5, Blood product unit identifier, in this case.
There are multiple result codes for mutiple units, Unit #1, Unit #2. Would I use 936-5 for each one of these?
I would concur with that usage as you describe. Different use cases would have different requirements. I did see a few other Blood bank codes that used a sequential numbering, such as for the expiration date of the different units, which only means some other system wanted to have discrete LOINC codes.