Snake bite in Australia: first aid and envenomation management
Section snippets
Snakebite season in Australia
Australia’s climate and proximity of national parks to major metropolitan areas provides opportunity for a range of outdoor activities. There is also an extensive rural population involved in agricultural and farming activities outside the metropolitan areas. Australians have a reputation for enjoying our extensive beaches, surf, mountains, rivers, and bush as part of their normal work and recreational activities. These opportunities are heavily promoted in local and overseas travel and holiday
Snakebite in Australia
Australia is inhabited by a large variety of snakes, many of which are amongst the most poisonous in the world. Snake activity is minimal during the cooler winter months, but as summer advances, and warm weather appears, people start to move their activities to the outdoors, and so do the snakes. Snakes are not confined to the rural areas of Australia. Snakes are regularly sighted (Harman 1999; Sprivulis & Jelinek 2000), and residents and visitors of metropolitan areas may experience snake bite
Australian snakes and their venom
There are over 140 recognised snakes in Australia (Shea 1999). Not all of these are venomous, and those that are (and represent those that are known to have caused envenomation in the human population) may be grouped into six main groups of brown snake, tiger snake, copperhead, black snake, taipan, and death adder (Shea 1999; White 1998). These large varieties of snakes inhabit known geographical areas. For example, the taipan is a highly venomous and aggressive snake that inhabits the northern
First aid
First aid techniques have been credited with reducing the fatalities associated with snakebite in Australia (AVRU 2000; Sprivulis & Jelinek 2000). Snake venom is circulated through the body via the lymphatic system, and the pressure-immobilisation-bandage or PIM Bandage is effective in reducing systemic envenomation (Sprivulis & Jelinek 2000). This is a technique that should optimally be employed at the time and scene of the snakebite. However, this is not always the case, and victims of bites
Application of the pressure-immobilisation bandage
The PIM bandage aims to compress tissues surrounding the bite, and hence slow lymphatic circulation of the venom. The PIM bandage is designed for snakebites to the limbs, as these are the most common sites (AVRU 2000). Local pressure should be applied to bites to the head, neck, and torso (AVRU 2000). Sprivulis and Jelinek (2000) suggest the use of adrenaline injected into the site to retard the spread of venom.
The following technique of administration of the PIM bandage was originally
Identifying the snake involved
It is necessary to identify if a snakebite has occurred, and as a separate responsibility, identify if envenomation of the victim has occurred. Fang marks are not always left after a snake has bitten. There may be a scratch, or it may not be possible to identify any marks at all (AVRU 2000). In this case it is necessary to rely on the patients description of where the bite occurred. It is important to realise that this does not exclude the possibility of snakebite, and assessment and management
Identifying envenomation
If venom has been identified through the VDK, it is then necessary to determine if the patient has been envenomated. Many patients, although certainly bitten by a snake do not experience envenomation (Sprivulis & Jelinek 2000). This will possibly have already been determined by the frequent assessment that will have been continuing throughout the venom identification process. Victims should be observed for signs of paralysis or paraesthesia, such as blurred vision, slurred speech. These are
Administering antivenom
Once systemic signs of envenomation have been identified, the patient is administered antivenom as an antidote. The antivenom of choice is indicated by the VDK, and supplies of appropriate antivenom should be maintained in hospitals within the known geographic snake habitats. These patients should be managed in an area fully equipped with resuscitative equipment.
In some cases there may be inadequate venom swabbed from the site, or the venom may not have been excreted into the urine to allow the
Absence of envenomation
Very few patients will experience envenomation despite receiving a snakebite. In these patients appropriate treatment involves removal of the PIM bandage under close observation in an area fully equipped with resuscitative equipment. Repeat blood tests should be taken and evaluated one hour after removal of the bandage. If there is no change in the patients condition or laboratory reports, the patient may be moved to an observation area for close monitoring and repeat blood tests at 6 and 12 h (
Conclusion
Snakebite remains a prevalent hazard in the Australian environment, although envenomation from snake bite has a relatively low incidence. Despite this, there has been a concerning increase in death from snake bite in recent years. This has been attributed to the inappropriate first aid management and lack of recognition of snake bite and envenomation. Emergency nurses need to be aware of the possibility of patients presenting with snakebite, the first aid measures required to minimise systemic
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