Definition
Venomous snake bites pose a significant threat to human health, primarily because of the toxic substances injected into the body. Snakes use venom for hunting prey and self-defense, and when humans are bitten, the venom can have severe consequences. In some cases, certain venom can also be sprayed into the human eye as a defensive mechanism. Globally, an estimated 4.5 to 5.4 million people suffer snake bites annually, with around 1.8 to 2.7 million individuals experiencing symptoms. Tragically, between 81,000 to 138,000 people die each year due to complications from these snake bites.
Causes
Venomous snake bites typically occur when a venomous snake, commonly a viper, feels threatened or disturbed by human presence. Studies indicate that in most cases, these bites happen incidentally when individuals come into contact with venomous snakes. However, there are instances where people may be unaware of the snake's presence, leading to bites. Vipers can be identified by a distinctive heat-sensing pit located between their eye and nostrils, which helps them detect heat from their surroundings, distinguishing living beings from inanimate objects.
The venom of snakes contains various proteins and non-protein substances, and many of these components have the potential to damage skin and muscle cells. Some components can induce clotting problems, either causing blood to clot more quickly or preventing clotting altogether. The composition of venom varies between snake species, leading to diverse effects. Venom may lead to platelet aggregation, slowing blood clotting, hindering nerve function resulting in weakness and paralysis, or causing facial swelling and low blood pressure. Additionally, certain venoms can trigger allergic reactions, widening blood vessels and leading to the spread of venom throughout the body.
Risk factor
Snakebites commonly occur among men, especially those who actively interact with snakes. If the interaction is intentional, the snakebite marks are often found on the arms. Other risk factors include:
- Having a Venomous Snake as a Pet
- Living in Rural Areas: In rural settings, snakebites often happen to farmers or workers who unintentionally step on or disturb snakes, resulting in bites on the legs or other body parts, particularly if individuals lie on the ground.
- Working in Beach Areas
- Geographic Factors: Snakebites primarily occur in tropical areas, but they can also happen in subtropical climates, particularly during the summer.
Children engaged in work, especially in rural areas, may face an elevated risk of snakebites. Limited access to education and healthcare facilities can further increase the risk, as can cultural practices prioritizing traditional treatments over seeking medical help, particularly affecting women in finding timely assistance for venomous snakebites.
Symptoms
Common symptoms experienced by individuals just bitten by a venomous snake include:
- Appearance of two stab wounds: Typically, snake bites result in two puncture wounds located close to each other.
- Swelling and redness around the bitten area.
- Pain is often felt in the vicinity of the bitten area.
- Difficulty Breathing
- Vomiting and Nausea
- Blurry Vision
- Profuse sweating and excessive saliva production
- Paralysis: Snake venom may induce paralysis, affecting the face and other body parts.
Additionally, certain snake venoms can trigger allergic reactions, leading to symptoms such as rash, swelling of the face, difficulty breathing, and a drop in blood pressure.
Diagnosis
Upon snake bite, venom poisoning begins, necessitating immediate and proper treatment. Recognizing snake bites as emergencies, quick first aid is crucial. Note the time of the bite, and characteristics of the snake (with photographic documentation if possible), and provide this information to medical professionals. Avoid bringing in a dead snake, as it may still contain venom. Observing the onset of symptoms is equally important.
Medical Assessment:
- Anamnesis: Medical professionals will inquire about medication and allergy history, any previous snakebites, and prior treatments with antivenom.
- Physical Examination: Checking the airway is critical due to potential allergic reactions and airway constriction caused by venom. Evaluation of breathing, circulation, and vital signs (blood pressure, pulse rate, temperature, breathing rate) is performed. Regular examination of the bite mark is conducted, along with neurological and cardiological assessments to gauge the venom's effects.
- Laboratory Examination: Various blood tests are conducted, including complete blood count, glucose levels, electrolytes, kidney function, blood clotting parameters, and markers for organ damage. If systemic signs of poisoning are present, liver function tests, urine analysis, blood typing, donor matching, and blood gas analysis may be performed.
- Imaging: Imaging studies are generally not routine. X-rays may be conducted if there's suspicion of a retained fang, while chest X-rays could be necessary for patients experiencing respiratory distress. Ultrasound (USG) may be used if signs of blood vessel blockage are observed.
Management
Before reaching the hospital, several critical steps should be taken:
- Call for help: Summon healthcare assistance promptly while ensuring the victim's safety from the snake.
- Document the incident: Note the time of the bite and track the onset of symptoms.
- Remain calm and still: Avoid unnecessary movements, as these can expedite the spread of venom throughout the body.
- Remove tight clothing or jewelry: Allow for potential swelling at the bite site.
- Avoid walking: Encourage the victim not to walk or make unnecessary movements. Transportation by vehicle is preferred.
- Handle the snake with caution: Do not attempt to kill or handle the snake excessively. Photographing the snake for identification can be done without wasting time.
- Avoid wound manipulation: Refrain from cutting or attempting to suck venom from the wound, as it can exacerbate the condition.
- Do not apply ice or alcohol: These substances should not be used on the wound.
Upon arriving at a healthcare facility, establishing an intravenous pathway is essential for fluid administration. The decision to administer antivenom depends on the severity of symptoms, as determined by the attending physician. Trained medical professionals will conduct wound cleaning, and surgery may be considered in cases of complications. Tetanus prevention injections can also be administered, and victims are typically monitored for a minimum of 12 to 24 hours to ensure proper management and observation of any potential complications.
It is crucial to stabilize the patient's condition, addressing issues related to circulation and neurological symptoms. Analgesics should be administered to alleviate pain resulting from the bite. Additionally, individuals are advised to avoid lifting or holding heavy objects on the bitten side not only during hospitalization but also for at least one week after receiving outpatient care. These measures contribute to a smoother recovery process.
Complications
Snake venom can lead to various complications, such as:
- Blood clotting problems
- Shock, leading to organ function failure due to ineffective blood circulation
- Difficulty breathing
- Acute kidney failure
- Skin infection around the bite
- Compartment syndrome (pressured nerves and blood vessels due to swelling)
Antivenom can prevent further tissue damage but cannot reverse existing damage. Fortunately, tissue damage around the bite site, often near the skin surface, has the potential to heal over time.
Prevention
Venomous snake bite can be prevented by:
- Avoiding snakes in nature.
- Avoid places where snakes may be hidden, such as high grass, piles of leaves, stones, or stacks of wood.
- If encountering a snake incidentally, give it some time to hide, as snakes naturally avoid interaction.
- When working in areas with potential snake presence, wear tall boots, long pants, and gloves.
- Avoid working at night and in warm weather, as snakes are usually active during these times.
When to see a doctor?
If you or someone nearby has been bitten by a snake, seek medical attention immediately. Treat all snakebites as potentially venomous. Take a moment to photograph the snake if possible, but don't waste time attempting to kill it. Keep yourself and others calm, avoid excessive movement, and ensure safety from the snake until help arrives or until you reach the nearest health facility.
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- dr Nadia Opmalina
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Meyers, S., & Tadi, P. (2022). Snake Toxicity. Retrieved 6 January 2022, from https://www.ncbi.nlm.nih.gov/books/NBK557565/
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