Medical personnel are supposed to obtain patients' consent before testing experimental treatments — but that can be tricky when the treatments take place at emergency scenes.

Such is the case with one study underway in St. Paul through the Regions Hospital EMS service, and now starting in Minneapolis with HCMC ambulance crews, to test a clotting drug on patients with traumatic brain injuries (TBIs).

Researchers suspect that "microbleeding" in the brain may exacerbate TBIs, even though doctors typically can't detect ruptures in tiny blood vessels. So this study will try tranexamic acid, an older drug that preserves blood clots, in the hope that it can prevent microbleeding, said Dr. Paul Nystrom, who is leading HCMC's arm of the study.

"There's been lots of studies that have come and gone with regard to TBI," he said. "There has never been a great study that has found a drug that has helped."

Trouble is, concussed patients at the scenes of falls or car wrecks can't be trusted to consent to research — even when conscious. So the study has gone through extra safety checks to allow the drug to be administered without consent.

HCMC issued a public notice this week, inviting people to seek more details or call 612-873-9528 to receive wristbands indicating they won't participate in the study.

Nobody requested the bands when Regions and a group of East Metro ambulance crews started their arm of the study last year, said Dr. R.J. Frascone, medical director of Regions EMS. "Far from people saying, 'We don't want that,' it was like 'How do I guarantee I get this?' "

The study is funded by federal military and health grants and the Canadian government. Mayo Clinic is participating in the 12-site study; Minnesota is the only state with three trauma centers involved.

Patients will be enrolled based on the severity of their brain injuries and vital signs and other demographics. They will either receive the intravenous drug or a saltwater placebo. The goal is to determine if the drug improves survival and mental recovery after severe TBIs.

Tranexamic acid isn't risk-free. It could elevate the risk of clot-related strokes, which is why TBI patients with histories of stroke and other diseases will be excluded.

Frascone said hospitals and medical helicopter crews already use the drug "off label" for this purpose. He suspects the study will prove its worth and broaden the drug's use.

Roughly 100,000 Minnesotans suffer TBIs each year.


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