Ambulance crews in the East Metro will be taking the unusual step this fall of testing a potentially lifesaving drug on brain-injured patients before they or their families consent to the research.

While patients or families will eventually consent to the study, researchers said they know of no other way to conduct the unusual study, which will test the ability of a medication known as tranexamic acid to halt bleeding in the brain without administering it immediately to trauma patients while they are incapacitated. “There is a time limit,” said Dr. R.J. Frascone, medical director for emergency medical services at Regions Hospital in St. Paul. “The earlier the drug is given, the better.”

Ambulance crews from the St. Paul Fire Department and the Lakeview, St. Croix and HealthEast EMS services will be participating along with Regions in the federally approved “exception” trial. The medication is commonly used to slow bleeding for other traumatic injuries, but hasn’t been studied in severe head injuries yet. “We really don’t have anything that is very effective with head injury,” Frascone said.

Patients with severe traumatic brain injuries, many in comas, will either receive doses of tranexamic acid both in the ambulance and at Regions, or a dose in the ambulance and a placebo at the hospital, or placebo doses in the ambulance and hospital.

Smaller studies have shown the drug to be safe. Now the goal is to reduce the death rate, around 25 percent, from these severe brain injuries.

In all, 11 U.S. sites will enroll 1,000 patients.

Tranexemic acid works best if given within 3 hours of an injury, or it can cause clotting complications that outweigh its benefits. The study requirement is for the drug to be given within 2 hours.