Snake Bites

Australia has around 140 species of land snake and 32 recorded species of sea snakes. Approximately 100 Australian snakes are venomous, although only 12 are likely to inflict a wound that could kill you. We have 9 of the top 10 deadliest snakes in the world, yet despite those statistics, Australia only records around 2-4 deaths annually (the lowest worldwide) compared with Asia that has around 15,000 – 57,000 annually (highest worldwide), while in Africa there are an estimated 3,000 to 32,000 deaths annually (second worldwide)[2007].

So, how do you know you have been bitten?

Sometimes you may not know. Snakebites, in the most part, are fairly painless.
Signs and symptoms can include:

• paired fang marks, but often only a single mark or a scratch mark may be present;
(localised redness and bruising are uncommon in Australian snake bite)
• headache;
• nausea and vomiting;
• abdominal pain;
• blurred or double vision, or drooping eyelids;
• difficulty in speaking, swallowing or breathing;
• swollen tender glands in the groin or armpit of the bitten limb;
• limb weakness or paralysis;
• respiratory weakness or respiratory arrest.

The most common cause of death from a snake bite is cardiac arrest. This can occur anywhere from 10min to 1hr from envenomation.

How do I treat a snake bite?

1. Send for an ambulance for any person with a suspected snake bite;
2. Keep the person still, reassured and under constant observation;
3. Apply pressure bandaging with immobilisation;
4. Commence CPR if a person is unresponsive and not breathing;

Note:
DO NOT cut or incise the bite
DO NOT use an arterial tourniquet
DO NOT wash or suck the bite
DO NOT try and catch the snake as secondary envenomation may occur. Instead, take a photo if safe to do so.

For much of Australia, polyvalent anti-venom that covers potential bites from different snakes is used.

What is Pressure Immobilisation Technique (PIT)?

Venom from Snakes, Funnelweb spiders, Blue Ring Octopus and Cone Shells travel through the lymphatic system. The lymphatic system is a network of tissues and organs that help rid the body of toxins, waste and other unwanted materials. Unlike the bloodstream, the lymphatic system requires movement of the limb/body to flow. Once the venom moves through the lymphatic system it then enters the bloodstream.

Pressure Immobilisation Technique (PIT) should ideally use an elastic bandage and are designed for limbs only (arms and legs). There are snake bite kits available that will have heavy elastic bandages with markers on them to help in gaining the required pressure on the limb. If the patient has any rings on their fingers you should remove them. We recommended you put a gauze pad over the bite, then wrap the limb with the PIT bandage starting over the bite area and working away from the heart, and then wrapping all the way up the limb. You should use a second bandage if the first one is not long enough, and finally, splint the limb to help stop any movement.

Remember, we are trying to stop/slow lymphatic flow NOT venus/arterial flow. Check the capillary refill of the fingers/toes of the affected limb for return of blood flow < 2 seconds.