Aug. 2, 2002 -- It's a scene played out in countless cowboy movies and survival shows: a hapless snakebite victim is rescued by a quick-thinking hero who sucks out the poison and spits it onto the ground. But experts say that approach to snakebite treatment is based far more on fiction than fact.

"The evidence suggests that cutting and sucking, or applying a tourniquet or ice does nothing to help the victim," says Robert A. Barish, MD, an emergency room physician and associate dean for clinical affairs at the University of Maryland School of Medicine, in a news release.

"Although these outdated measures are still widely accepted by the general public, they may do more harm than good by delaying prompt medical care, contaminating the wound or by damaging nerves and blood vessels," says Barish.

Barish and colleagues at the Rocky Mountain Poison Center in Denver reviewed the research on snakebites and their treatment in an article published in the Aug. 1 issue of TheNew England Journal of Medicine.

Of the estimated 120 different types of snakes found in the U.S., about 20 are poisonous. Although most bites occur the southwest part of the nation, at least one type of poisonous snake has been identified in every state except Alaska, Hawaii, and Maine.

Some of the most commonly found venomous snakes are pit vipers, such as rattlesnakes, cottonmouths, and copperheads.

Researchers say many people believe that any bite from a poisonous snake will lead to illness or death. But that's no longer the case.

About 25% of all pit viper bites are "dry" and don't contain any of the snake's dangerous venom. In addition, since the advent of effective antivenom, the death rate from pit viper bites has dropped to less than one half of one percent. Back in the frontier days of the 19th century, up to 25% of these snakebites were fatal.

Snakebites are most common in the spring and summer, when people are outside camping or hiking in the snake's natural habitat. But researchers say most bites are a result of a deliberate attempt to handle or disturb the snake. Alcohol intoxication also plays a role in many of these cases.