TUESDAY, April 23, 2002 (HealthDayNews) -- Drinking too much alcohol not only increases your risk of getting hurt; it may put you in added danger if you suffer an injury that makes you bleed.
That's because alcohol impairs the body's ability to maintain normal blood pressure even after just minor bleeding, says new research from the Louisiana State University Health Sciences Center.
The study is the first one to look at how alcohol affects the body's ability to regulate blood pressure, claim the researchers, who will present their findings tomorrow at the Experimental Biology 2002 meeting in New Orleans.
Experts say the research could prove valuable to doctors and nurses working in emergency rooms. Approximately 25 percent of emergency room patients have "alcohol problems," federal health officials say.
In the study, a group of laboratory rats was given alcohol to simulate a man on an alcohol binge. Those rats had a greater drop in blood pressure after they'd had a small amount of blood taken from them than control rats that received no alcohol, says research leader Dr. Patricia E. Molina, an associate professor in the department of physiology.
The rats were given alcohol over 15 hours. The amount was comparable to a 165-pound man drinking 2.5 beers an hour, also for 15 hours. The rats' blood alcohol levels were 0.18 to 0.19 grams of alcohol per 100 milliliters of blood. In many states, the legal limit for driving is 0.08.
To test the rats' physical responses, the researchers then drew blood from both groups of animals until they reached a predetermined level of reduced blood pressure. It took 20 percent less blood loss in the intoxicated rats to reach that targeted level than in the control rats.
Even before being bled, the intoxicated rats had a mean blood pressure decrease of 20 percent.
The drunk rats also took longer than their counterparts to regain their normal blood pressure after receiving fluid replacement -- the equivalent of an IV drip given to human patients.
"We saw the response to fluid resuscitation in the animals that were drunk was delayed. Eventually, they do reach the same blood pressure as the control animals, but it takes a longer period of time and the response is not as immediate as you would see in a control animal," Molina says.
This research may be important for trauma patients and the doctors who treat them. If it takes longer for a drinker's blood pressure to stabilize after blood loss, that means organs have to go longer with an inadequate oxygen supply. That can be especially hazardous for organs such as the brain, liver and kidneys, which are heavy oxygen users, Molina says.
Between 20 percent and 30 percent of patients seen in U.S. emergency rooms have alcohol problems, according to the National Center for Injury Prevention and Control. But emergency rooms don't routinely screen patients for alcohol problems.
Normally, when you suffer even a small amount of bleeding, the brain takes action to restore normal blood pressure. It does this by releasing chemicals, including adrenaline, into your circulatory system.
But alcohol intoxication seems to blunt that response -- it was reduced by 50 percent to 60 percent in the intoxicated rats -- and delay recovery of normal blood pressure.
"What this is telling us is that the body has lost its ability to compensate to try to maintain an ideal blood pressure," Molina says.
Molina says there's been a great deal of research into how to prevent alcohol abusers from injuring themselves. But there hasn't been much focus on how the bodies of people who are drunk cope with injury-related blood loss.
Understanding that can help find ways to improve care for these people and reduce medical costs.
"Many times this is just ignored. There's so much to do at the time [in an emergency room]. But what some people have started to realize is that the drunk victim is quite different than the victim who is not drunk," Molina says.
"Just the mere fact of knowing that the individual is not going to be as responsive and will not restore their blood pressure as quickly as a non-intoxicated person" is vital information for doctors, nurses and paramedics, Molina adds.
An emergency medicine expert says this study may prove invaluable to emergency-room personnel.
At least 50 percent of major injuries and 22 percent of minor traumas are alcohol-related, says Dr. Gail D'Onofrio, associate professor of emergency medicine at Yale University School of Medicine.
"Therefore, the implications of the study are great to all emergency departments and trauma centers. Understanding how to better manage major trauma patients who are hemodynamically unstable and acutely intoxicated would be a major step forward," she says.
What To Do: For more information about alcohol-related injuries, visit the Trauma Foundation or the National Center for Injury Prevention and Control.
