Envenomation occurs when venom enters into a person’s body causing systemic or localized poisoning. Although deaths due to envenomation are rarely reported in Canada, it can cause serious complications that may require hospital admission, even intensive care. Venom is a poison that is secreted by an animal such as snake, jellyfish, or spider. It is normally transmitted through sting or bite. There are countless creatures in Canada that possesses venom and can potentially be lethal to humans. These creatures can be found on land as well as on water. To learn to recognize and manage envenomation and other first aid emergencies sign up for first aid training here.
Envenomation can cause a wide range of signs and symptoms. Venoms are comprised of different toxins or components that affect the body systems in unique ways. Most of these venoms affect voluntary nerves and autonomic nerves that interfere with vital body functions, especially that of smooth muscle (heart and lungs) and nervous system (brain and spinal cord).
Some of the possible signs and symptoms resulting from envenomation include the following:
- Localized tissue damage
- Pain and swelling of the sting/bite site
- Dizziness or light headedness
- Low blood pressure
- Blurred vision
- Abdominal pain
- Nausea and vomiting
If not treated, envenomation can lead to more serious complications that include:
- Involuntary muscle movements (twitching)
- Muscle weakness or paralysis of body parts.
- Sudden loss of consciousness
If you suspect someone has been bitten by a venomous creature and professional emergency services are not available, you can help minimize the spread of toxins in the body by using the Pressure Immobilization Technique or Bandaging. The poisonous compounds of venoms gain access to the circulatory system through the lymphatic system, applying pressure on the lymph vessels can retard the flow of these toxins, thereby delaying potential harmful effects.
A lot of people think that the first aid to bites from venomous creatures is to cut the bite area or suck out the venom. Instead of controlling the poison, it can only add harm to the victim. Tourniquet and washing the bite area IS NOT advised.
Pressure immobilization technique is recommended for envenomation caused by:
- Snakebites (all snakes including sea snakes)
- Cone shell
- Mouse spider and funnel-web spider
However, pressure technique is not recommended for envenomation due to:
- Fish stings
- Stings or bites from beetles, scorpions or centipedes
Applying pressure immobilization bandage:
- Prioritize the needs of the victim; resuscitation and controlling severe bleeding takes priority over applying pressure.
- Mark the bite site.
- Preserve the venom sample by covering the bite site with a clean piece of cloth. Apply firm pressure bandage over the bite site.
- Apply firm pressure bandage starting from the distal part of the extremity (toes or fingers) the going upwards along the length of the limb. If possible, the entire extremity should be bandaged to further retard the flow of the toxins through the lymphatic system.
- Use splint to restrict movement of the affected extremity.
- Keep the victim calm and still. Assist to lie down.
- Provide first aid treatment to other injuries.
- Keep the bandage in place while waiting for emergency help to arrive or while transporting the victim.
- If the bite or sting is not on the limb, apply direct firm pressure, using a pad.