A Department of Defense-funded study led by Michael J. Joyner, M.D., an anesthesiologist at Mayo Clinic's campus in Rochester, Minnesota, looks at how the body responds to blood loss.

The objective is to help the U.S. Army develop better monitors to determine who needs a blood transfusion in battlefield or trauma situations and at what point the body starts to decompensate. 

This determination is important as vital signs for the wounded often don't change much until the patient suddenly collapses, making it critical for providers caring for him or her to determine when and how much blood should be administered.