(Feb. 28, 2005)
In the movies, a poisonous snake in the woods bites a teen, and his friends tie a tourniquet around his leg and drive him to a hospital. There, he is given antivenin and a lecture about wandering around in the woods without an adult. He is discharged a few hours later.
If it were only so simple, said Dr. William J. Meggs, professor of emergency medicine and a toxicologist at the Brody School of Medicine at East Carolina University.
Meggs and his colleagues studied the effectiveness of tourniquets and elastic bandages used with splints in treating bites from the Eastern coral snake
(Micrurus fulvius). Eastern coral snakes are found from Texas to southern North Carolina and as far north as Arkansas.
“The project worked out great because the issue is how do you treat snake bites in the field. People have debated whether or not to use a tourniquet,” Meggs said. “The Australians recommend wrapping the limb with the bite in an Ace bandage and putting on a splint. The venom travels up the lymphatic system, but the Ace bandage is enough to slow down or stop the flow without compromising blood flow.”
He explained the flow of lymph is controlled by the flexing and stretching of muscles, such as when walking. Thus the splint helps immobilize the limb and slow down that process. Other researchers have traced the flow of lymph using radioactive dye, Meggs said, but no one has looked at the effectiveness during an actual envenomation.
Dr. Benjamin German developed the idea to test the Australian theory as part of his senior residency research project at the medical school. After completing his residency last July, he moved to Prescott, Ariz., where he works as an emergency physician and is continuing his study of snakebites and treatments. Along with German and Meggs, Dr. Jason Hack, assistant professor of emergency medicine and a toxicologist, and Dr. Kori Brewer, research director for the Department of Emergency Medicine, worked on the project.
Meggs praised German’'s work and his continuing research in the field of snakebites. "I would predict that within ten years, he will be an international expert on snakes and their venom,"” Meggs said.
The group’s findings were presented in October at the American College of Emergency Physicians in San Francisco and have been accepted for publication to the Annals of Emergency Medicine.
In their research, Meggs and his colleagues tested pressure immobilization in delaying the onset of systemic toxicity in animals injected with coral snake venom. All of the animals who received no bandaging and splinting died with three to four hours; 80 percent of the treated animals survived for the 8-hour length of the experiment.
The group used venom from a biological supply company. “Snakes had been milked for venom, and that’s good because then we could know exactly how much venom we were injecting,” Meggs said.
“"The definitive treatment for snakebite is antivenin,"” Meggs said, "sSo the question is what happens if you’'re out in the woods with no antivenin or the antivenin is hours away? What can you do to keep the poison from traveling through a person’s body quickly? For this coral snake experiment, the use of Ace bandages and splints proved to be a rousing success.”
U.S. poison control centers have received an average of 63 reports of bites from coral snakes annually for the past five years, the researchers said in their article. The incidence of reported bites has been increasing, and in 2002 88 were reported, the most ever. The mortality rate of untreated envenomations (the introduction of poison venom into the body by bite or sting) is reported to be near 10 percent, although no deaths have occurred in the United States since antivenin was introduced in 1967, the researchers said. No coral snake bites have be