About 45,000 people are bitten by snakes every year in the United States. Of
those, 7,000 involve poisonous snakes, and of those treated, only about 15 die.
More than half of the poisonous snakebites involve children, and most occur
between April and October. Of the poisonous bites in the United States, 55
percent are from rattlesnakes, 34 percent from copperheads, 10 percent from
water moccasins, and one percent from coral snakes. Rattlesnake bites account
for 70 percent of the fatalities and between 95 and 98 percent of the bites
occur on extremities. Each year the Samaritan Regional Poison Center has more
than 65 calls about rattlesnake bites.
There are 11 species of rattlesnakes identified in Arizona. A pit viper snake
has a heat sensing "pit" located between the nostril and eye on each
side that is used to locate and trail prey. Rattlesnakes can grow up to six feet
in length. Baby rattlesnakes are capable of a venomous bite from birth.
Nonpoisonous snakebites are not considered serious and are generally treated as
minor wounds; only poisonous snakebites are considered medical emergencies.
Symptoms generally occur immediately, but only about one third of all bites
manifest symptoms. When no symptoms occur, probably no venom was injected into
the victim. In 50 percent of coral snake bites, no venom is injected because the
coral snake has to chew the skin for envenomation to occur. In as many as 25
percent of all venomous pit viper bites, no venom is injected, possibly because
the fangs may be injured, the venom sacs may be empty at the time of the bite,
or the snake may not use the fangs when it strikes. Poisonous snakebite venom
contains some of the most complex toxins known; venoms can affect the central
nervous system, brain, heart, kidneys, and blood.
Signs that indicate a poisonous snakebite
include:
The bite consists of one or two distinct puncture wounds. Nonpoisonous snakes
usually leave a series of small, shallow puncture wounds because they have teeth
instead of fangs. The exception is the coral snake, which leaves a semicircular
marking from its teeth. Because some poisonous snakes also have teeth, fang and
teeth marks may be apparent. The presence of teeth marks does not rule out a
poisonous bite, but the presence of fang marks always confirms a poisonous
snakebite.
Characteristics of pit viper snakes:
Large fangs; nonpoisonous snakes have small teeth.
The two fangs of a poisonous snake are hollow and work like a hypodermic
needle.
Pupils resemble vertical slits.
Presence of a pit. Pit vipers have a telltale pit between the eye and the
mouth. The pit, a heat-sensing organ, makes it possible for the snake to
accurately strike a warm-blooded victim, even if the snake cannot see the
victim.
A triangular or arrowhead shaped head.
The rattlesnake often shakes its rattles as a warning. BUT
NOT ALWAYS!
One snake that is not a pit viper snake but is poisonous is the coral snake.
The coral snake is highly poisonous and resembles a number of nonpoisonous
snakes. It does not have fangs and has round pupils. Because its mouth is so
small and its teeth are short, most coral snakes inflict bites on the toes and
fingers. They have to chew the skin a while to inject venom. Coral snakes are
small and ringed with red, yellow, and black. The chances for recovery of a
snakebite are great if the patient receives care within two hours of the bite.
You can decide how serious the bite is by
considering several factors:
The age, size and general health of the patient. A small child will
probably react much more severely to a smaller amount of venom than will an
adult. Bites are most dangerous in children and the elderly.
The depth, location and number of bites. A single, glancing blow by the
fangs is much less dangerous than multiple wounds or wounds that penetrate
the flesh deeply. A bite that penetrates a blood vessel is extremely
dangerous. The least dangerous bites occur on the extremities and in fatty
tissue. Bites on the head or trunk are usually fatal.
The duration of the bite. The longer the bite, the greater the amount of
venom that may be injected into the patient's system.
Clothing. A snake that bites through several layers of clothing will not
leave as much venom as a snake that strikes bare skin.
Maturity, type, and size of the snake. Small snakes usually do not produce
enough venom to seriously harm an adult.
Condition of the fangs and venom sacs. More venom will be injected if the
fangs and venom sacs are in good condition.
How angry or fearful a snake is. More venom will be injected if the snake
is angry or fearful.
Treatment for snakebite:
The severity of a pit viper bite is gauged by how
rapidly symptoms develop, which depends on how much poison was injected. Signs
and symptoms of a pit viper bite include:
Immediate and severe burning pain and swelling
around the fang marks, usually within five minutes. The entire extremity
generally swells within eight to 36 hours.
Purplish discoloration around the bite, usually
developing within two to three hours.
Numbness and possible blistering around the bite,
generally within several hours.
Nausea and vomiting
Rapid heartbeat, low blood pressure, weakness, and
fainting
Numbness and tingling of the tongue and mouth
Excessive sweating
Fever and chills
Muscular twitching
Convulsions
Dimmed vision
Headache
The priorities of emergency care for snakebite are to maintain basic life
support - airway, breathing and circulation - and limit the spread of the venom
and to transport the patient without delay.
Move the patient away from the snake to prevent repeated bites or bites to
yourself. Snakes cannot sustain prolonged rapid movement so are often within
a 20 foot radius of where the bite first occurred.
Have the patient lie down and keep him quiet. Reassure him to slow the
metabolism and subsequent spread of the venom.
Cut and suck methods are useless. According to one study, the most you can
get is six percent of the venom. Many people do far more damage when they
cut than they do good.
Keep the bitten extremity at the level of the heart.
Remove any rings, bracelets or other jewelry that could impede circulation
if swelling occurs.
Clean the wound gently with alcohol, soap and water, hydrogen peroxide or
other mild antiseptic.
Do not cool or chill or apply ice.
Do not attempt to tie any type of tourniquet or constricting bands.
Transport the patient as soon as possible to the hospital. Signs and
symptoms of a coral snake bite are different than those of a pit viper.
Rather than leaving two distinct fang marks, the coral snake leaves one or
more tiny scratch marks in the area of the bite. There is little pain or
swelling and the patient's tissue usually does not turn black and blue.
Usually, there is no pain or swelling at the bite site. However, one to
eight hours after the bite, the patient will experience blurred vision,
drooping eyelids, slurred speech, increased salivation and sweating.
Emergency care for a coral snake bite is similar to that for a pit viper
snake bite.
