We have an e-mail distribution list for duplicate medical record number issues. I get at least 2 or 3 notices per day and keep them all in a three ring binder. If there is no blood bank history for either number, then I just let registration take care of it however they take care of those things. If there is a blood bank history on one of the numbers, I send a specific e-mail stating that this patients records MUST be merged into one. Unfortunately, they will not do so until the patient has been discharged from their current stay. If there is a clinically significant history on one number, I add it to the other number with a comment. (We also have Meditech) But like R1R2 says, you can only deal with the information you are given.