Sunday, May 7, 2006
By TOM VOGT, Columbian staff writer
Most people who participate in medical studies get a chance to weigh the pros and cons of a new drug or technique being used on them.
It’s called informed consent. It’s hard to get when an unconscious accident victim has been rescued from a crumpled car.
That’s an issue Oregon Health & Science University researchers must deal with in a nationwide study that will involve people in Clark County with traumatic injuries.
Local paramedics and EMTs and regional hospitals also will participate.
Researchers want to know if a different type of saline solution, administered intravenously at an accident site, will improve survival or recovery of brain function.
“The biggest thing we struggle with is giving enough fluid so you don’t have an organ problem,” said Roxy Barnes, the Vancouver Fire Department’s administrator of emergency medical services.
“If we give too much fluid, it causes swelling in the brain, which creates more problems with a brain injury. We have to give enough to keep the blood pressure up; but if we overshoot, there is the potential of causing more damage to the brain,” she said.
The Food and Drug Administration allows research in some life-threatening situations without patient approval, but researchers must make sure the community is aware of the study.
OHSU will hold a community meeting Monday at Southwest Washington Medical Center to get public opinion. The session will be at 7 p.m. in the Health Education Center of the hospital, 600 N.E. 92nd Ave.
Similar meetings will be held in Multnomah, Clackamas and Washington counties, where OHSU also will conduct the research. The study, funded by the National Institutes of Health, includes 11 regional medical centers in the United States and Canada.
People with traumatic injuries now receive intravenous saline solution, which is water with the same salt content as blood about 0.9 percent.
“We don’t know if it is the best solution,” said Dr. Mohamud Daya, an associate professor of emergency medicine at OHSU. “We’ve done it for a long time.”
But a small amount of data from human tests, and data from animal testing, suggests that a more concentrated solution 7.5 percent salt will give trauma victims a better chance of survival, he said.
It is believed the extra-salty, or hypertonic, saline will allow blood flow to be restored with a smaller amount of fluid than regular saline; it will avoid overcrowding blood vessels and also reduce inflammation.
“With the normal fluid we use now, only a portion stays in the vascular space. A lot leaks out,” Daya said. “If I give 1,000 cc, maybe a quarter stays in the vascular space. With the hypertonic, I give less: 250 cc; that’s like a cup of water.”
At the same time, the extra-salty solution pulls fluid from cells into the blood vessel system, Daya said, so “with 250 cc, you get the equivalent of 1,000 cc in the vascular space.”
Drawing fluid away from tissues also helps people with traumatic brain injuries.
“That actually reduces brain swelling,” Daya said.
There also will be another version of the hypertonic saline. An added sugar molecule, dextran, seems to make the solution more effective.
To be eligible for the study, subjects must have severe injuries with either low blood pressure or an altered mental state. OHSU expects most eligible subjects to be involved in motor vehicle accidents. Pregnant women and individuals under arrest at the time of the accident will not be eligible.
If accident victims meet the criteria, emergency medical responders will start an intravenous delivery of saline from a supply designated for the study. Those not eligible will get a standard saline solution. All bags will be bar-coded.
No one will receive more than one bag of hypertonic saline. Subjects enrolled in the study, and their family members, will be informed as soon as possible.
The study is expected to begin in June.
Tom Vogt can be reached at 360-759-8008 or [email protected]
If you go
What: Community meeting to get public opinion on trauma study overseen locally by OHSU.
When: 7 p.m. Monday.
Where: Health Education Center at Southwest Washington Medical Center, 600 N.E. 92nd Ave.