Exactly, Steve.
That is one of the problems with a recent paper published by Dr. Aryeh Shander. That paper is discussed in this thread here:
Not only did Shander and his research team drop out the patients who died in the first 24 hours but they also did not include the second surgery those bloodless patients may have had. The results of that study are useless because the methodology is flawed.
*to add-
another flawed research paper about bloodless surgery: