I agree with John, comming from a major metropolitan transfusion service, I would say that the earlier it is called the better for bb, the docs, and the pt. we have a standard kit ready to go in a cooler, 8 rbc, 2ffp. Once one cooler is out the door, we start getting the next ready. A lot of doc's forget about the ffp when they get a big bleed, thats why having a standard of how many units you can use before you have to use the ffp is helpful. in any case other than a MT, we require coag studies after 4 units. After 8 units, you can quit typing and crossmatching.