TREATING SPIDER BITE

Bite Prevention Spiders do not set out to harm people. A common sense approach will reduce the chances of your being bitten by a spider, and in most cases, prevent it from happening. Wearing suitable footwear and gloves while gardening and exercising caution when moving things around your shed or garden are examples of simple precautions that should be taken.

SEEK MEDICAL ADVICE IF BITTEN BY A SPIDER OF ANY TYPE

First Aid

The vast majority of spiders are harmless to humans. A bite from most spiders will heal quickly, producing very few side effects. Even the more dangerous spiders in Australia rarely produce effective envenomations. (People react differently. The type of reaction depends upon a number of factors that range from the size of the spider, to the size of the person.) On most occasions, first aid will not be necessary for spider bite victims. However, it is always best to be cautious. Suspected bites by Funnel-webs and Red-backs should always be taken seriously and medical advice should be sought immediately. The pressure-immobilization method should only be used in the treatment of a Funnel-web Spider bite.

First Aid for a Funnel Web bite only Technique developed by the Commonwealth Serum Laboratory

1 Remove the patient from danger. DO NOT attempt to catch the Funnel Web, but note any distinguishing characteristics that will assist with its positive identification.

2 Reassure the patient, keeping them as calm and as still as possible. Do not clean or even wipe the bite. Any residue of venom from skin or clothing can be used by medical staff for positive identification of the offending spider.

3 Apply a broad, firm bandage directly over the bite and as far up the limb as possible, remembering to keep the limb still. Even removing clothing would cause movement which must be avoided. The same tension that you would use for a sprained ankle is enough; the aim is to restrict the lymph flow and not restrict the blood flow. The bandage should be able to be tolerated comfortably for some hours if necessary. (Creep bandages are the most ideal but torn up clothing could also be used).

4 immobilize the limb by applying a splint, over clothing if necessary. A bitten arm can be immobilized using a splint and a sling; an effective method of immobilizing a bitten leg is to bind it to the patient’s other leg.

5 Call an ambulance and be sure to give precise directions as to your location. Bring transport as close to the victim as possible.

6 Ask the patient questions to obtain a brief medical history: e.g. Is the patient an asthmatic? Are they using any medication? This information may be important.

7 DO NOT give alcohol under any circumstances. If respiration stops, administer mouth-to-mouth resuscitation.

8 The pressure bandage should not be removed except by medical staff.

Keeping the victim still and calm is one of the most important actions. Panic only hastens the spread of the venom through the lymphatic system and also makes it difficult for medical staff to separate the symptoms of Funnel Web bite from shock. Antivenoms are now available for funnel web bites. With prompt action, proper first aid and medical treatment, surviving even the most serious of Funnel Web bites is a high probability.

Tiger Snake Envenomation

First Aid for tiger snake envenomation is pressure-immobilization

The snakes in the group defined here are grouped together because of similarity in clinical aspects of the envenomations they may cause. Several genera are represented, and among the species included are:

• Mainland Tiger Snake
• Black Tiger Snake
• Rough-Scaled Snake
• Copperheads
• Pale-Headed Snake
• Broad-Headed Snake
• Stephen's Banded Snake
• Small-Eyed Snake

Signs and Symptoms

Tiger snake venom has a wide range of effects on humans. It contains pre-synaptic and post-synaptic neurotoxins, myotoxins and procoagulants. Significant envenomation by any species of this group may result in:

1. Neurological impairment
2. Paralysis
3. Incoaguable blood
4. Rhabdomyolysis
5. Renal failure secondary to myolysis

Treatment

First aid for tiger snake envenomation consists of a pressure bandage and immobilisation. In cases where a pressure bandage has been applied correctly, it can be left in situ indefinitely while the patient is feeling no discomfort as a result. If it becomes appropriate to remove a pressure bandage, it is necessary to have antivenom and haemostatic support ready. In severe cases, a patient may require ventilatory support.

Antivenom is indicated for any clinical manifestations of neurotoxicity, myolysis or severe coagulopathy.

Antivenom

Tiger snake antivenom can be used effectively for envenomation by any of the species listed above.

Tiger snake antivenom supplied by CSL Ltd is equine in origin.

Brown Snake Envenomation

First Aid for brown snake envenomation is pressure-immobilisation

Brown snake is widespread outside urban areas, and particularly common around buildings in rural environments. The group is the most important in terms of fatalities, being responsible for more deaths in the last twenty-five years than any other group. The fact that brown snakes are very fast-moving also adds degree to the danger they present. While all snakes are generally variable in appearance, brown snakes are remarkably so, leading to possible problems with identification.

Among the toxins contained in their venom is a very potent presynaptic neurotoxin, one of the strongest of toxins found in snakes. The venom also contains a postsynaptic neurotoxin and a procoagulant. Unlike the venom of most dangerous Australian elapids, that of brown snakes has littles or no myolytic activity.

Signs and Symptoms

Early collapse, a few minutes after the bite, is not infrequent in cases of brown snake envenomation, possibly due to haemostatic disturbance resulting from coagulopathy. Bloods will typically indicate prolonged clotting times. Thrombocytopenia is also evident from haematology. One diagnostically distinct feature of brown snake enevenomation is the absence of rhabdomyolysis, which in cases involving other species manifests as myoglobinuria. Coagulopathic effects can also result in disseminated intravascular coagulopathy, putting the patient at risk of cerebrovascular accident.

Treatment

First aid for brown snake envenomation consists of a pressure bandage and immobilisation. In cases where a pressure bandage has been applied correctly, it can be left in situ indefinitely while the patient is feeling no discomfort as a result. If it becomes appropriate to remove a pressure bandage, it is necessary to have antivenom and haemostatic support ready. In severe cases, a patient may require ventilatory support.

Brown Snake Antivenom

It is generally accepted that the initial treatment for syptomatic brown snake envenomation involves administration of two ampoules of monovalent Brown Snake Antivenom. Brown snake antivenom supplied by CSL Ltd is equine in origin.

Black Snake Envenomation

The First Aid for black snake envenomation is pressure-immobilisation

Black Snake Envenomation: Signs and Symptoms

The venom of mulga snake is somewhat less toxic than that of many other Australian venomous snakes, among them the black snake. Mytoxicity is a major feature, and the venom also contains anticoagulants and possibly neurotoxins. Swelling and pain at the bite site may be seen, and are unusual in bites by other Australian snake genera.

Red-bellied black snake bite may cause coagulopathy, neurotoxicity, and myolysis. No human deaths have been confirmed, although animals have died after bites by this snake.

Bites from the blue-bellied black snake may cause severe local pain and regional lymphadenopathy.

Black Snake Envenomation: Treatment

First aid for black snake envenomation consists of a pressure bandage and immobilization. In cases where a pressure bandage has been applied correctly, it can be left in situ indefinitely while the patient is feeling no discomfort as a result. If it becomes appropriate to remove a pressure bandage, it is necessary to have antivenom and haemostatic support ready.

Antivenom

Black snake antivenom should be used for envenomation by the mulga snake and Collett's snake.

Tiger snake antivenom is just as effective in treating envenomation by the red-bellied black snake and blue-bellied black snake, and is preferable because of its lesser volume.

Black snake and tiger snake antivenom supplied by CSL Ltd are equine in origin.