Snake bites are a major public health issue, with an estimated 5 million bites annually resulting in over 100,000 deaths. Sri Lanka has a particularly high rate, with 800 deaths annually from bites mainly by three venomous snakes. Snake venom contains various toxins that can cause local and systemic effects from bleeding and clotting disorders to neurotoxicity and kidney damage depending on the snake type. Symptoms of envenoming may include pain and swelling at the bite site, nausea, vomiting and visual changes. Prompt first aid and antivenom treatment can prevent death and complications from snake bites.

2.  It is estimated that there are about 5 million snake bites every year, of
those it’s estimated around 2.4 million are envenoming
 These snake bites cause around 94 000 to 125 000 deaths annually with an
additional 400 000 amputations and other consequences -infection,
tetanus, scarring, contractures, and psychological sequelae
 Most snake bites are caused by non-venomous snakes
 Of the roughly 3000 known species of snake found worldwide, only 15%
are considered dangerous to humans
 Snakes are found on every continent except Antarctica

3.  In Sri Lanka there are about 65 000 snake bites annually
 More people die of snake bite in Sri Lanka than in any other
comparable area in the world
 An average of 800 people are killed by snakes every year on the
656,120Km² (25,332miles²) island - equivalent to one person every
82Km² (32 miles²) annually
 Over 95% of the fatalities are caused by the common krait (Bungarus
caeruleus), the Sri Lankan cobra (Naja n. naja) and Russel's pit viper
(Vipera russelli pulchella)

4.  Snake Venom :
 Snake venom is made up of more than 20 different compounds, mostly
proteins and polypeptides
 Procoagulant enzymes (activate coagulation cascade)
 Phospholipase A2 (myotoxic, neurotoxic, cardio toxic – cause hemolysis,
increase vascular permeability)
 Proteases (tissue necrosis)
 Polypeptide toxins (disrupt neuromuscular transmission)
 Lethal dose of venom of certain snakes :
Cobra-0.12gm, Krait-0.06gm- Russell’s V-0.15gm

5.  Highly venomous
 Russell’s viper
 Hump-nosed viper
 Saw scaled viper
 Sea snake
 Cobra
 Common krait
 Ceylon krait

6. Russell’s viper
Hump nosed viper

7. Sea snake
Cobra

8. Ceylon krait

9.  Moderately venomous
 Cat snake
 Green-pit viper

10.  Non-venomous snakes
 Rat snake
 Wolf snake

12.  Puncture mark or scratches on suspected bite area. At times marks could not
be visible
 Bleeding at bite site, unusual pain around the bitten area and limb, swelling
 Nausea, headache, vomiting , stomach ache, difficulty in swallowing or
drinking
 Double or blurred vision
 Drooping eyelids
 Difficulty in talking.
 Bleeding in gums.
 Dark or brownish urine bloody urine.
 Giddyness
The following are few of the most common symptoms of envenomation due
to a snake bite. Symptoms may occur soon after the bite or take hours to
appear.
A minimum of twenty-four hour observation of the patient is suggested.

13. These images of actual bite marks
by venomous snakes show that
marks may or may not be clearly
visible.
Bite marks dependent on the type
and size of snake in question.
Common locations of snake bites

14. Drooping eyelids
Change in color of tissue around the bite area
Swelling in the limb
Blisters in the bite
area
Signs and symptoms of a venomous snake
bite

16. Envenoming
Local Systemic
Specific Non Specific

17.  Fang marks
 Local pain
 Local bleeding
 Bruising
 Lymphadenitis
 Inflammation (swelling, redness, heat)
 Blistering
 Local infection
 Necrosis

18.  Cardiovascular signs and symptoms - hypotension
 Bleeding and clotting disorders – 20 min whole blood clotting time
 Neurotoxicity – ptosis, respiratory impairment
 Rhabdomyolysis with myoglobinuria
 Renal

19.  Nausea
 Vomiting
 Malaise
 Abdominal pain
 Weakness
 Drowsiness

20. Snake type Local reaction clotting Neurological Renal
Russell’s viper + + + +
Hump nosed viper + + +
Saw scaled viper + +
Cobra ++ +
Krait +
Sea snake +

21.  Attempt to retard systemic absorption of venom
 Preserve life and prevent complications before the patient can receive
medical care
 Control distressing or dangerous early symptoms of envenoming
 Arrange the transport of the patient to a place where they can receive
medical care

23.  Anti-venom is the only specific antidote to snake venom
 A most important decision in the management of a snake bite victim is whether or not to
administer anti-venom
 Indications for anti-venom. Anti-venom treatment is recommended if and when a patient with
proven or suspected snakebite develops one or more of the following signs
1. Systemic envenoming
2. Haemostatic abnormalities : spontaneous systemic bleeding,
coagulopathy(20WBCT,prothrombin time) thrombocytopenia(less than 100*109 per litre)
3. Neurotoxic signs (ptosis, external opthalmoplegia, paralysis)
4. Cardiovascular abnormalities (hypotension, shock, cardiac arrhythmia)
 In Sri lanka given to all patients with systemic envenomation except in hump nosed viper bite
and sea snake bite
 If the snake is identified as nonvenomous patient can be discharged after a booster dose of
tetanous toxoid.

24.  Anti-venom administration must be temporarily suspended
 Epinephrine(0.1%solution,1 in 1000,1mg/ml)is the effective treatment
for early anaphylactic and pyrogenic anti-venom reactions
 All patients should be watched carefully for 2 hours after the
completion of anti-venom administration and should be treated with
epinephrine/adrenaline at the fist sign of a reaction

25.  Q.a farmer presents with a history of snake bite but could not identify or
kill the snake. His foot is swollen and painfull and bite site is necrotic. b/l
partial ptosis. uop is normal. rft normal. 20 min wbct normal. what is the
most likely snake
1. Russell’s viper
2. Cobra
3. Hump nose viper
4. Sea snake
5. Saw scale viper

27. THANK YOU