  Blood transfusion is a frequently performed medical procedure in surgical and
nonsurgical contexts. Although it is frequently necessary or even life-saving,
it has been identified as one of the most overused procedures in hospitals.
Unnecessary transfusions not only waste resources but can also be detrimental
to patient outcomes. Patient blood management (PBM) is the clinical practice of
optimizing transfusions and associated outcomes. In this paper, we introduce
Sanguine, a visual analysis tool for transfusion data and related patient
medical records. Sanguine was designed with two user groups in mind: PBM
experts and clinicians who conduct transfusions. PBM experts use Sanguine to
explore and analyze transfusion practices and its associated medical outcomes.
They can compare individual surgeons, or compare outcomes or time periods, such
as before and after an intervention regarding transfusion practices. PBM
experts then curate and annotate views for communication with clinicians, with
the goal of improving their transfusion practices. Such a review session could
be in person or through a shared link. We validate the utility and
effectiveness of Sanguine through case studies.
