2. INTRODUCTIONSnake bite is an important
public health hazard in
Bangladesh
Estimated an annual
incidence of 623/100,000
6,041 deaths annually.
Neurotoxic snakes like
(Cobra, Kraits) are causing
significant mortality and
morbidity
Among the vipers green pit viper
is very common but there are few
cases of Russell's viper.
Rahman R,Faiz MA,Selim S,Rahman B, Bashar A,et el.Annual incidence of snake bite in rural Bangladesh.
PLoS Negl Trop Dis.2010 Oct;4(10):e860.
10. âş A bite by venomous snake which produces specific
symptoms or a syndrome is considered as venomous snake
bite.
âş A venomous snake may not and do not always features of
envenoming
âş 50% of bites by Russellâs viper , 30 % of bite by Cobras
and 5-10% of bites by saw scaled viper do not result in any
symptoms or signs of envenoming
âş A victim may develop some features due to anxiety or
apprehension in case of bite by a venomous as well as NV
snake.
11. Traits Poisonous Non Poisonous
1. Colour Generally brightly coloured Usually not brightly coloured
2. Shape of head long, triangular and posterior
portion is wide
narrow and elongated
3. Neck always constricted. No constriction
4. Hood Present Absent
5. Tail abruptly tapered tapered and long except
burrowing snakes
6. Head scales usually small Scales on the top of the head are
large
7. Dorsal scales are smaller but the spinal
(vertebral) scales are larger
longer but spinal (vertebral)
scales are not longer and
hexagonal
8. Loreal shield Present Absent
9. Teeth Most of the teeth are solid and uniform
except maxillary teeth which are large,
and provided with groove or canal.
These large teeth are called âFangsâ.
Uniform and solid
12. Traits Poisonous Non Poisonous
10. Poison Gland Present Not Present
11. Mental shield Fourth one is large. Small
12. Muscular system
Less- developed Well-developed
13. Lungs One of the lungs has either
been reduced or absent.
Both lungs are present.
14. Hypophysis developed throughout the
vertebral column.
absent or present on the posterior
dorsal vertebrae.
15. Streptostylism Well marked Absent
16. Example: Saw Scaled Viper (Echis
carinatus), Common Krait
(Bungarus caeruleus), Banded
Krait (B. fasciatus), Russellâs
Viper (Vipera russelli), King
Cobra (Ophiopagus hannah),
Indian Monocled Cobra (Naja
naja kaouthia).
Rat Snake (Ptyas mucosus),
Indian Python (Python molurus),
Sand Boa (Eryx conicus),
Checkered keel back [Natrix
(Xenocrophis) piscator], Wolf
Snake (Lycodon aulicus), Striped
Keel back (Amphiesma stolata).
13. Total no. of snake species -98
Total no. of venomous snake species- 32
Total no. of non-venomous snake species- 66
Total no. of threatened snake species(IUCN 2000) -28
Snakes in Bangladesh:
Venomous snakes in Bangladesh:
ďą Common krait (Kal-keutey)
Monocellate cobra (Gokhra)
Spectacled cobra (Khoia gokhra)
King cobra (Padmagokhra)
Banded krait (Shankhini shap)
Russellâs viper (Chandro-bora)
Green pit viper (Sabuj bora)
Spot-tailed pit viper (Tila-leji
sabuj bora)
14. Most venomous snake in land:
Inland Taipan.
Top most venomous snakes:
Belcher's Sea Snake
16. â˘Where (in which part of your body) were you
bitten?
â˘When were you bitten and what were you
doing when were you bitten?â
â˘Where is the snake that bit you?â What did it
look like? did anyone take a picture?â
â˘How are you feeling now?â
Non specific symptoms:
Headache, Nausea, vomiting, abdominal pain,
loss of consciousness, difficulty in vision, convulsion.
17. Neurological symptoms:
1. Muscle paralysis
2. difficulty in moving jaw,toungue,eye
3. heaviness of eye lids (ptosis)
4. weakness of neck muscles (broken neck sign)
5. difficulty in swallowing, dribbling of saliva
6. nasal regurgitation, nasal voice
7. difficulty in respiration,
8. extreme generalized weakness
Haematological symptoms:
1. Spontaneous bleeding from gum,
2. vomiting of blood, Coughing out of blood,
18. 3. passage of blood per urethra,
4. persistent bleeding from bite site, venepuncture site and
inflicted wound if any.
Others:
Severe muscle pain, dark urine, scanty urination, collapse.
Concomitant medical illness:
H/O allergy, Bronchial asthma, kidney, heart disease,
bleeding disorders, neurological disease, limb swelling etc.
In female:
Whether the victim is pregnant or not, whether the victim
menstruating or not.
19. H/O pre hospital treatment:
1. Home treatment.
2.Treatment from traditional healers (Ozha or Baiddya).
3.Application of tourniquet.
4.H/0 immunization against tetanus.
5.Treatment by initial attending physician.
21. Early clues that a patient has severe envenoming:
⢠Snake identified as a very dangerous one or a large specimen
⢠Widely spaced fang puncture marks or evidence of multiple
strikes
⢠Rapid early extension of local swelling from the site of the
bite
⢠Tender enlargement of local lymph nodes, indicating spread
of venom in the lymphatic system
⢠Systemic symptoms: collapse (hypotension, shock), nausea,
vomiting, diarrhoea, severe headache, âheavinessâ of the
eyelids, inappropriate (pathological) drowsiness or early
ptosis/ophthalmoplegia
⢠Spontaneous systemic Bleeding
⢠No urine passed since the bite
⢠Passage of dark brown/black urine
22. 1.Rapid clinical assessment especially vitals:
Pulse, BP, Respiration, Temp
2.Systemic signs of envenoming:
Chronology of onset and progression of signs.
a. Neurotoxic sign:
⢠Ptosis(Partial or complete) usually symmetrical and progressive
⢠Diplopia, external ophthalmoplegia
⢠Bulbar palsy
⢠Nasal voice
⢠Facial paralysis
⢠Inability to open the mouth and to protrude the toungue
⢠Paralysis of chest muscle and diaphragm (Shallow breathing)
⢠Broken neck sign: Weak grip, diminished reflexes
24. b.Signs of haematological abnormality:
⢠Persistent bleeding from bite site, venepuncture site
and or inflicted wound if any
⢠Multiple bruise or large blood collection
⢠Haemorrhagic blisters
⢠Bleeding from gingival sulci
⢠Haemoptysis
⢠Haematuria
⢠Epistaxis
28. Examination of the bitten part:
⢠Extent of swelling
⢠Lymph nodes
⢠A bitten limb may be tensely oedematous,
cold, immobile, painful on passive movement
and with impalpable arterial pulses.
â˘Early signs of necrosis may include blistering,
demarcated darkening(easily confused with
bruising) or paleness of the skin, loss of
sensation and a smell of putrefaction(rotting
flesh).
29. Identification of snake
⢠Identification of snake by description or by model,
photograph, brought snake, preserved specimen.
By local examination-
⢠Classic fang and teeth mark rarely occur and if present
indicate venomous snake bite
⢠Scratch usually indicates nonvenomous snake bite but may
rarely found in krait bite
⢠Snake may bite through clothing
33. ⢠First-aid treatment
⢠Transport to hospital
⢠Rapid clinical assessment and
resuscitation
⢠Detailed clinical assessment and
species diagnosis
â˘Investigations/laboratory tests
⢠Antivenom treatment
⢠Observing the response to antivenom
34. ⢠Deciding whether further dose(s)
of antivenom are needed
⢠Supportive/ancillary treatment
⢠Treatment of the bitten part
⢠Rehabilitation
⢠Treatment of chronic
complications
⢠Advising how to avoid future bites
35. Recommended First Aid
1. Reassurance
2. Immobilization of whole body
3. Apply Pressure Pad Immobilization.
4. Avoid any interference with the bite wound
CAUTION: Delay the release of tight bands,
bandage & ligatures
37. PLEASE KEEP IT IN MIND
⢠DO NOT WASTE TIME TO ANY OZHA OR
TRADITIONAL HEALERS
1.NOT scientific
2.Waste of time
3.May cause infection, bleeding, gangrene
4.Damage to artery , vein
5.Loss of life
6.Always harmful
38. HARMFUL- NOT RECOMMENDED
1.Tight tourniquets
2.Incision at the bite site
3.Local suction
4.Cauterization by chemicals
5.Application of materials
6.Ingestion of herbal products to induce vomiting
7.Unnecessary delaying
39.
40. Treatment in Hospital
1. Rapid clinical assessment and resuscitation (ABC)
Assisted Ventilation, Blood Transfusion
2. Detailed clinical assessment
(Local, Neurological, Haematological)
3. Identification of species
(Brought snake live, dead or description,photograph
20 min WBCT, Syndromic approach)
41. Treatment:
a.Antibiotic
b.Tetanus prophylaxis
c.Antivenom
Polyvalent Antivenom:
In our country now only Polyvalent antivenom from Vins (lindia)
is available in lyophilized powder form. Each vial contain 10 mg
of antivenom, which is effective against systemic envenoming
by Cobra, Krait, Russell's Viper and Saw scaled viper only
(there is no evidence of Saw scaled viper in Bangladesh). So
this type of antivenom should not be used in bites by Green
snake, Sea snakes and identified non-venomous snake.
42. Antivenom Treatment
Indication /criteria for using antivenom:
(Not indicated in Green snake and sea snake)
1.Neurotoxic signs.
2.Rapid extension of swelling (more than half of the bitten
limb). N.B- not due to green snake bite or tight tourniquet.
3.AKI (not due to sea snake).
4.Cardiovascular abnormalities
5.Bleeding abnormalities.
6.Haemoglobinuria/myoglobinuria not due to sea snake.
43. Anti snake venom therapy
⢠Dose:
Each dose consists of 10 vial of polyvalent antivenom
irrespective of age and sex of the victim.
⢠Time and administration:
Each vial is diluted with 10-ml. of distilled water. 10 such vials
(100 ml) is further diluted or mixed with 100 ml of fluid
(Dextrose water or saline). Then it is administered with
intravenous infusion within 40-60 min (60-70 drops/min).
⢠Observation and monitoring:
Continuous observation and frequent monitoring of vital signs
should be ensured during antivenom therapy and few hours
after its completion. Careful clinical assessment for appearance
of signs and symptoms of antivenom (A/V) reaction should be
performed.
46. Criteria for repeating the initial dose of antivenom:
Persisting or deteriorating signs of systemic antivenom.eg.
1. If no improvement or deterioration of neurotoxic
features (cobra or krait) 1-2 hours completion of
antivenom.
2. Persistence or recurrence of blood coagulopathy
after 6 hours of antivenom treatment.
47. Drugs not recommended:
1. Antihistamine except for antivenom
reaction
2. Corticosteroid except antivenom reaction
3. Sedative
4. Antifibrinolytic agent
5. Heparin
6. Traditional medicines (from ozahs)
48. Treatment of bitten part:
⢠Elevation of limb with rest
⢠Simple washing with antiseptic solution
⢠Broad spectrum antibiotic (especially when there is
features of contamination, multiple incisions)
⢠In case of local necrosis and gangrene:
Broad spectrum antibiotic
Surgical debridement and split thickness skin
grafting is indicated.
⢠In case of Compartment syndrome: Fasciotomy
49. Follow up:
Local envenomation:
1. Need to follow up for at least 5- 7 days to see the sequential
changes of color changes, blisters, ulceration, necrosis and
desquamation.
Children :
To observe any neurological residual deficit present or not with
also attention to neurocognitive function.
Pregnancy:
Long term follow up of children is also needed to see the
neurological cognitive function.
50. Rehabilitation:
ďą Physiotherapy
ďą Reconstructive surgery
Discharge assessment
⢠Implications of having had a snakebite:
⢠Rehabilitation exercises:
⢠Follow-up appointment: encourage the patient to return after an interval
of 1-2 weeks to check on their progress and to allow further reassurance.
⢠Late serum sickness-type reactions: warn them of the symptoms and
reassure them that this complication of antivenom can be treated.
⢠Reducing the risk of further bites: provide advice, ideally in the form of
a leaflet, explaining the principles of snakebite prevention , to be shared
with their familiesand neighbours.
51. What should we do when no
antivenom is available?
Incase of neurotoxity:
⢠Assisted ventilation via ambu bag or mechanical ventilation
⢠Inj.Atropine and Neostigmine
In case of Haematological abnormality:
⢠Strict bed rest to avoid even minor trauma
⢠I/M injection must be avoided
⢠Fresh whole blood or FFP transfusion should be given