about snake bite ,venom,types of venom,first aid,antivenom,and management ,epidemiology ,dosage and route of antivenom administration , anaphylactic reaction due to antivenom , general symptoms of snake bite,immobilization process , formation of antivenom

3. Objectives
Introduction
Epidemiology
Venom
Component of venom
Difference between poisonous and non poisonous snake
Classification of venom
Management

4. Snake
A long limbless reptile which has no
eyelids ,a short tail, and jaws that are
capable of considerable extension .

5. Introduction
Snake bite are punctured wounds caused by the
fangs of snakes where it release it’s venom.
• 3500 Species found globally 500 species are
poisonous
• In Nepal 77 species known, 22 of these are
poisonous. Studies in Nepal have identified 4
species of snake responsible for fatal bites. They
are indian cobra(naja naja),common krait(bungaris
caeruleus), Russell’s viper(viper ressellii) and
greenpit viper

6. cobra
Greenpit
viper
Common krait
Russells
viper

7. Epidemiology
There are at least 40,000 cases of snakebite every
year in Nepal,with some fatalities in terai alone.
Death rate has come down from 18.7% 20 years
ago to 6.62% . India has the highest number of
deaths due to snake bites in the world with 35,000–
50,000 people dying per year according to World
Health Organization (WHO) direst estimates. South
Asia has the highest incidence and mortality rates of
snake bite in the world.

8. Venom
A poisonous substance secreted by animals
such as snakes,spiders ,and scorpions and
typically injected into prey by biting or stinging.
Freshly secreted venom is transparent and
pale.
On storing and on exposure to light it
becomes yellowish and opaque

10. Component of venom
Contains 20 different constituents mainly
proteins including enzymes and polypeptide
toxins.
Procoagulants
Other cytolytic or necrolytic toxins

12. Difference between poisonous and non
poisonous snake
S.N Poisonous snake Non-poisonous snake
1 Fangs are hollow like hypodermic
needle
Fangs are short and solid
2 Belly scales are large and cover
entire breadth
Belly scales are like those on back
and don’t cover the entire breadth
3 Teeth are two long fangs Teeth are several and small

13. Classification of venom
1. Haematotoxic venom
2. Neurotoxic venom
3. Myotoxic venom
4. Cytotoxic venom
(NOTE- Most snakes have both type of venoms but one
is dominant to the other.)

14. 1.Haematotoxic venom
Affect blood and circulation . The prey dies from
cardiovascular failure and bleeding.
Sign and symptoms
Vomiting
Numbness , confusion
Intense pain
Bruising , bleeding
Rapid pulse

15. 2.Neurotoxic venom
Affects the nervous system and brain.
Signs and symptoms
Ptosis
Respiratory paralysis
Double vision,dilated pupil
Sweating,vomiting
Excessive salivation
Muscle paralysis
It takes about 10 min for the venom to affect nervous system
Neurotoxic symptom usually resolve in 2-3 days

16. 3.Myotoxic venom
Affect muscle tissue
Sign and symptoms
Most important symptom are rhabdomyolysis(rapid
breakdown of skeletal muscle tissue)and paralysis
Disable muscle contraction
Pain in legs ,hips and shoulders,with paralysis and
damage to kidney

17. 4.Cytotoxic venom
Destroy cells
Sign and symptoms
Bleeding , Blistering and discolouration
Painful and progressive swelling
Examples of venom
Sea MY HEAVY NECK
Myotoxic -Sea Snake
Hematotoxic – Viper (Viperidae)
Neurotoxic- Cobra, Krait (Elapidae)

19. Management
1) First aid treatment and transport to hospital
2) Rapid clinical assessment and resuscitation
3) Antivenom treatment
4) Treatment of bitten part
5) Prevention

20. 1.First aid
a. Reassurance
The victim may be frightened and anxious . Reassure
victim on that it is a treatable condition . The confirmation can be
done by presence of teeth prints . Remove tight clothes,rings etc
from bitten limb .
b. Immobilization
Immobilize the bitten limb with a splint or sling . Any cloth or
bandage may be used for this. Any form of movement cause musle
contraction that will increase absorption and spread of venom by
squeezing vein . Keep the affected limb as low level as possible .
Regularly check circulation in fingers or toes.
c. Rapid transport

22. First aid if venom enter in eye
I. Irrigating the eye with water or if possible normal
saline
II. A single application of local anesthetic eye drops
helps to overcome tightly closed eyelids and facilitates
irrigation
III. Antivenom treatment is not indicated

23. First aid of bite to trunk
If possible apply firm pressure over the bitten area.
Donot restrict chest movement and keep patient still
First aid of bite in neck
 There is no first aid keep patient still and take to
hospital

24. Do’s
Immobilize the limb
Get to hospital immediately . traditional remedies
have no proven benefit in treating it
Tell the doctor if any systemic symptom that
manifest on the way to hospital

25. Don’t
Interfere with bitten area
Suck by mouth
Apply chemicals
Use tourniquets
Cooling agents on bitten area
Make incision
Walking
Give anything to eat

26. 2.Rapid clinical assessment and resuscitation
 It is a medical emergency. Therefore a quick clinical assessment
should be done to decide if patient needs immediate resuscitation
or antivenom therapy . Rapid clinical assessment and resuscitation
using ABCDE( airway , breathing, circulation,disability of nervous
system , exposure and environmental control ) approach should be
initiated .
Airway obstruction or respiratory failure caused by neurotoxic
envenoming requires immediate airway support
In case of russells viper bite,shock may occur because of
hemorrhage due to incoagulable blood , fluid shift into bitten
limb,myocardial depression . This patient must be treated promptly
with rapid infusion of normal saline and antivenom started as soon
as possible .

27. 3. Antivenom treatment
►It is only effective treatment for snake bite envenoming . It is
prepared from animals plasma ( most often horses , but also
donkey or sheep ) after hyper immunized against venom of snakes
►The currently available antivenom in Nepal is imported from
india and is polyvalent(hyperimmunized against venom of several
snake species) available in lypophilized powder form . Each vial is
reconstituted with 10ml of sterile water for IV administration. It is
effective against 4 common species of snakes found in india ;
Russells viper (Daboia russelii), common cobr (naja naja) ,common
krait (bungarus caeruleus) and saw scaled viper (echis carinatus).
Saw scaled is not yet reported from Nepal .

29. Indication for administering antivenom
Administration of antivenom carries risk of
anaphylactic reaction and should not therefore be
used unnecessarily
Evidence of neurotoxicity
Evidence of coagulopathy which is detected by
bleeding
Evidence of cardiovascular collapse eg. Shock and
hypotension

30. Route of administration and dosage of
antivenom
Adult
Reconstituted antivenom is diluted in 5-10 ml/kg body
weight (approx. 250-500 ml) of isotonic saline or glucose
and administered as infusion @2ml/min.
Children
Reconstituted antivenom is diluted in 3-5 ml/kg body
weight of isotonic saline or dextrose water and
administered as infusion @2ml/min
Reconstituted antivenom is administerd by slow iv
@2ml/min however,this route is not practiced commonly

31. Neurotoxic envenoming
Initial dose 10 vials (100) ml is further diluted or
mixed with dextrose water or saline(100
ml to 400 ml) . Then it is administered with
iv infusion at rate of 2ml/min (@60-70
drops /min).
Repetition of antivenom dose If neurological signs deteriorates an iv
push of 5 vials of antivenom (50ml)
reconstituted antivenom should
administer @2ml/min
Note :donot repeat if neurological sign
persist.repeat only if deteriorate
Cont…

32. Hematotoxic envenoming
Initial dose Same as for neurotoxic envenoming
Repetition of
dose
Persistence of blood incoagulability
after every 6 hr of antivenom dose .
Repeat coagulation test if it comes
abnormal repeat 5 vials of antivenom
(50 ml reconstituted antivenom) iv
push@2ml/min
Cont…

33. Observation and monitoring
Patient receiving antivenom requires continuous
observation and frequent monitoring of vital signs .
The anaphylaxis reaction may be life threatening so
adrenaline(s/c) must be kept ready . 3 types of
antivenom reaction can occur ,early anaphylactic
reaction (EAR) , pyrogenic reaction and late
reaction .

34. Detection of early EAR and PR (pyrogenic
reaction
It usually occurs within 3hours after initiation of
antivenom administration. Following are associated
features :
1) Itching,urticaria,swollen lips or tongue
2) Respiratory symptoms:dry
cough,wheezing,stridor,hoarse voice
3) Nausea,vomiting,diarrhea
4) Airway obstruction,fever
5) Tachypnea,shock Urticaria

35. 4.Treatment of bitten part
1) Elevation of limb with rest
2) Simple washing with antiseptic solution like
chlorhexidine , povidone iodine etc
3) In case of local necrosis and gangrene surgical
debriment should done
4) Snakebites are considered tetanus prone wounds
.so,tetanus toxoid IM injection should given . If patients
presents with coagulopathy , it should postponed until
after resolution of coagulopathy .

36. 5.Prevention
It is a seasonal events . It occurs when snake comes out of hibernation
and after rain . Following preventive measures should be taken :
1) Keep household clean by cutting grasses,bushes building materials
etc from near and around house .
2) Close door ,windows properly so that snake cannot enter house.
3) Try to avoid sleeping on floor . If it is unavoidable ,then mosquito net
should be used and tucked well.
4) Use light when you walk outside the house at night .
5) Use high shoes or boots while walking in paddy field .
6) Never insert hands into long grasses,holes etc
7) Shoes and clothes should be check before wearing .

37. Reference
National guideline for snakebite management in Nepal
K park 24th edition