Defining clinically important perioperative blood loss and transfusion for the Standardised Endpoints for Perioperative Medicine (StEP) collaborative: a protocol for a scoping review.

This scoping review of the previously published literature does not require research ethics approval. The results will be used to inform a consensus-based process to develop definitions of clinically important perioperative blood loss and transfusion. The results of the scoping review will be published in a peer-reviewed scientific journal.