About author :
Latha Bai P*, Dr. Hindustan Abdul Ahad
Dept. of Pharmaceutics, Balaji College of Pharmacy, Anantapur, AP, India
Snakebite is an injury caused by a bite from a snake, often resulting in puncture wounds inflicted by the animal’s fangs and sometimes resulting in envenomation. Although the majority of snake species are non-venomous and typically kill their prey with constriction rather than venom, venomous snakes can be found on every continent except Antarctica. Snakes often bite their prey as a method of hunting, but also for defensive purposes against predators. Since the physical appearance of snakes may differ, there is often no practical way to identify a species and professional medical attention should be sought.
The outcome of snake bites depends on numerous factors, including the species of snake, the area of the body bitten, the amount of venom injected, and the health conditions of the person. Feelings of terror and panic are common after snakebite and can produce a characteristic set of symptoms mediated by the autonomic nervous system, such as a racing heart and nausea. Bites from non-venomous snakes can also cause injury, often due to lacerations caused by the snake’s teeth, or from a resulting infection. A bite may also trigger an anaphylactic reaction, which is potentially fatal. First aid recommendations for bites depend on the snakes inhabiting the region, as effective treatments for bites inflicted by some species can be ineffective for others.
The number of fatalities attributed to snake bites varies greatly by geographical area. Although deaths are relatively rare in Australia, Europe and North America, the morbidity and mortality associated with snake bites is a serious public health problem in many regions of the world, particularly in rural areas lacking medical facilities. Further, while South Asia, Southeast Asia, and sub-Saharan Africa report the highest number of bites, there is also a high incidence in the Neotropics and other equatorial and subtropical regions. Each year tens of thousands of people die from snake bites, yet the risk of being bitten can be lowered with preventive measures, such as wearing protective footwear and avoiding areas known to be inhabited by dangerous snake
Key Words : Snake bite, first aid, treatments.
1. As with any medical emergency, remember to be quick and don’t panic
2. 3/4th of all Indian snake species are non-venomous.
3. Most snake bite deaths in India are caused by four venomous snake species, for which a Polyvalent anti snake venom serum (PASVS) is available.
4. PASVS is the only known and reliable cure for snake-bite by any one of these snakes.
5. The four species, sometimes called the ‘big four’, are the Indian cobra, Common krait, Saw-scaled viper and Russell’s viper.
6. Before administering PASVS, it is important to try and ascertain whether you’ve been bitten by a venomous or non-venomous snake.
7. The snake can be identified if you are able to collect it in a bag, with minimal handling.
8. Alternately make a note of as many details about the snake as possible such as colour, markings and size.
9. In case of a venomous snake bite or if you are uncertain about the identity of the snake, here are the first aid steps to follow:
10. Calm the patient down to slow down blood circulation and retard the spread of venom.
11. Quickly clean the site of the wound with some water and, if available, disinfectant.
12. If the bite is on the arms or the legs, tie a loose tourniquet (two fingers should just about fit under tourniquet) using soft cotton cloth or rope, above the wound on the upper arm or upper leg. If it takes more than 20 minutes to get to a doctor make sure to slightly loosen the tourniquet for a minute every 20 minutes.
13. Do not attempt to suck out venom as it can potentially place the first aid giver at risk and is ineffective at removing venom.
14. Do not attempt to make cuts around the site of the bite as it can cause infection and is also ineffective at removing venom.
15. Get to a doctor as quickly as possible and report the bite, with a description of the snake. If possible, arrange for transportation so that the 16. patient does not have to exert himself, thereby increasing blood circulation.
Medical Treatment of Snake Bite :
This is provided for information purposes ONLY and has been obtained from published and other sources and may not be up to date. It should not be used in determining the treatment of an envenomed patient. Specific information or advice can be obtained from a clinical toxicologist.
1. Admit to Intensive Care Unit.
2. Leave pressure immobilization bandages in place (Very Important).
3. Obtain anti-venoms and Venom Detection Kit.
4. Obtain intravenous access.
5. Take blood group and X-match, coagulation screen (including fibrinogen levels and tests for DIC, full blood count, electrolysis and calcium, creatinine kinase and arterial blood gases. Perform ECG. Repeat at appropriate intervals.
6. Collect urine for microscopy to detect hematuria and for free protein, hemoglobin and myoglobin measurement. Record urine output. Freeze the first sample for venom detection.
7. Draw up adrenaline. Antihistamine and steroids in case of anaphylaxis to anti-venom.
8. When ready, cut a hole over the wound site, inspect and take swabs for use with venom detection kit.
9. Once results of venom detection kit are known, slowly and progressively remove bandages. Do not remove all at once.
10. If no symptoms ensue monitor for at least 24hrs as delayed onset is possible in some species of snakes.
11. If systemic symptoms ensue, reapply bandages and administer anti-venom as clinically indicated. Anti-venoms should be diluted in 100ml of N. Saline, 5% dextrose or Hartman’s immediately prior to administration.
12. Ensure patient is well hydrated to reduce risk of acute renal failure due to rhabdomyolysis.
13. Repeat blood tests, ECG etc., at clinically relevant intervals.
14. Correct abnormal coagulation; look out for disseminated intravascular coagulation (heparin probably contra-indicated in DIC from snake bite), Analgesia and sedation – be cautious.
15. Correct hypotension, if present; with volume expansion and vasopressors (exclude occult bleeding).
16. Watch for development of renal failure – monitor urine output and composition. Tetanus prophylaxis recommended.
Take care at time of snake bite and take immediate near medical treatment.