A snake bite is an injury caused by the bite of a snake. It often results in two puncture wounds from the animal’s fangs. Since envenomation is completely voluntary, all venomous snakes are capable of biting without injecting venom into a person.
Snakes may deliver a ‘dry bite’ rather than waste their venom on a creature too large for them to eat. However, the percentage of dry bites varies among species: 80 percent of bites inflicted by sea snakes, which are normally timid, do not result in envenomation. Most species of snake are harmless and many bites are not life-threatening,
All snakes will bite when threatened or surprised, but most will usually avoid people if possible and only bite as a last resort. Children are at higher risk for death or serious complications due to snake bites because of their smaller body size.
Poisonous snake bites include bites by any of the following: Cobra, Copperhead, Coral snake, Cottonmouth (water moccasin), Rattlesnake and various snakes found at zoos.
SIGNS AND SYMPTOMS
Clinical manifestations depend on the type of snake and includes:
- A pair of puncture marks at the wound
- Redness and swelling around the bite
- Nausea and vomiting
- Labored breathing (in extreme cases, breathing may stop altogether)
- Disturbed vision
- Increased salivation and sweating
- Pain at the bite site
- Numbness and tingling in the face and limbs
- Bleeding from wound
- Excessive sweating
- Fainting and weakness
- Increased thirst
- Loss of muscle coordination
- Rapid pulse
- Tissue death
- Skin discoloration
Snake venom is a complex mixture of many different compounds. The composition and effects of venom varies considerably between species to species, but can broadly be divided into categories which include:
Cytotoxins causing local swelling and tissue damage
Haemorrhagins which disturb the integrity of blood vessels compounds which lead to incoagulable blood
Neurotoxins causing neurotoxicity
Myotoxins which cause muscle breakdown
- Remain calm and move beyond the snake’s striking distance.
- Restrict movement, and keep the affected area below heart level to reduce the flow of venom.
- Remove any rings or constricting items because the affected area may swell. Create a loose splint to help restrict movement of the area.
- Clean the wound, but don’t flush it with water.
- Cover it with a clean, dry dressing.
- Monitor the person’s vital signs – temperature, pulse, rate of breathing, and blood pressure — if possible. If there are signs of shock (such as paleness), lay the person flat, raise the feet, and cover the person with a blanket.
- Get medical help right away. Getting to an emergency room as quickly as possible is very important. If properly treated, many snake bites will not have serious effects. Snake bites can be deadly if not treated quickly.
- If the snake is dead, take it with you for identification. Do not waste time hunting it down. Be careful of the head when transporting it — a snake can actually bite for up to an hour after it’s dead (from a reflex).
- Do not apply a tourniquet.
- Do not suck out the venom by mouth or suction pump.
- Do not apply ice or immerse the wound in water.
- Don’t cut the wound or attempt to remove the venom.
- Do not raise the area of the bite above the victim’s heart.
- Don’t drink caffeine or alcohol, which could speed the rate at which your body absorbs venom.
- Do not give the victim any medications unless directed by a doctor.
- Don’t try to capture the snake. Try to remember its color and shape so that you can describe it, which will help in your treatment.
- This person should not be allowed to walk. Do not allow the person to become over-exerted. If necessary, carry the person to safety.
- Spread of venom is through the lymphatic system and can be prevented by applying a pressure bandage and not a tourniquet to the wound and splinting.
- Give tetanus prophylaxis
- Administer antibiotics to prevent secondary infection
- Clean wound and debride necrotic tissue
- Perform fasciotomy if there is marked swelling.
- Relieve pain and anxiety with analgesics. Administer pethidine if pain is severe
- Confirm indication for anti-venom. Give polyvalent antivenom if in doubt but if snake species is known give the specific monovalent.
- Counteract the systemic effects of venom. If the situation is life threatening, administer an antivenom. This is a substance that is created with snake venom to counter the snake bite symptoms. It is injected into the victim intravenously. The sooner the antivenom is used, the more effective it will be in saving the patient.
- Perform artificial ventilation if respiratory muscle paralysis is suspected
- Transfuse fresh whole blood in cases of hemorrhagic shock