• 3500 Species
• 300 Venomous
• 30000 - 40000 Death annually
o India
o Brazil
o Buruma
Poisonous Snakes
5 families
- Crotalidae-rattle snake,pit viper
- Viperidae-russel’s ,sawscaled viper
- Elapidae-cobra,krait
- Hydrophiodae-sea snake
- Colabridae
Indian scenario
5 dangerously poisonous snakes
· king cobra
· common cobra
· common krait
· russell’s viper
· sawscaled viper
Most common poisonous snake is common krait
· 216 species
· 52 venomous
· Ireland
· Newzealand
Snake venom
· Toxic saliva secreted by modified parotid glands of a venomous snake
· Amber coloured when fresh
Constituents
· Toxins
· Enzymes
· Neurotoxins
· Cardiotoxins
· Hemolysin
Venom apparatus
Fangs
Venom classification
· Neurotoxic-Elapids(cobra,krait)
· Hemotoxic-Viperidae
· Myotoxic-Sea snake
Krait and russell’s viper is much more toxic than that of cobra
Symptomatology of non venomous snakes
· Universal fear associated induce a state of shock
· Bite site may demonstrate multiple teeth impressions
· Lack of significant local pain or swelling
· Adequate reassurance and symptomatic treatment measures lead to full recovery
Symptomatology of venomous snakes
1. Elapid bite
Local features:
· Indistinct fang marks ,
· Burning pain,
· Swelling and discolouration,
· Serosanguinous discharge
Systemic features
· Preparalytic stage: Emesis,headache, LOC.
· Paralytic stage: ptosis,ophthalmoplegia drowsiness,dysarthria, dysphagia,convulsions, bulbar paralysis, resp failure .
2. Viperid bite
Local features:
· Rapid swelling,
· Discolouration,
· Blister formation,
· Bleeding from bite site,
· Severe pain
Generalised bleeding manifestations.
- epistaxis,
- hemoptysis,
- bleeding gums
- hemauria
- purpuric spots
- Renal failure
Hydrophid bite
Local features:
§ minimal swelling and pain
Systemic features:
§ Myalgia muscle stiffness
§ Myoglobinuria ,
§ Renal tubular
§ Necrosis
Diagnosis of snake bite
1. Fang marks:classically, two puncture wounds seperated by a distance varying from 8mm to 4cm, depending on the species involved.
2. However a side swipe may produce only a single puncture,while multiple bites could result in numerous fang marks.
3. Bailey’s method
Identification of snake
§ Poisonous or non poisonous
§ Species
Venomous Non venomous
Stout, dull coloured abruptly tapering tail | Slender,brightly coloured gradually tapering tail |
Tail: may be rounded or flattened | Always rounded |
Belly scales are broad | Belly scales are small..do not extend the entire width |
Head :triangular | Rounded or oval |
Head scales: usually small | Usually large (shields) |
At least one pair of teeth in the upper jaw are modified to form fangs | All teeth are uniformly small in size |
Saliva contains toxic peptides and enzymes | Non toxic |
Non-venomous snakes
Kurudan
 | |||||
| Red Sand Boa |
Eryx conicus (chenathandan)
 |
| Python |
 |
| Bronze back tree snake |
 | ||
| Ckeckered keelback |
 |
| Striped keelback |
 |
| Cat Snak |
The Venomous snakes
 |
| Banded krait |
 |
| Hook nosed sea snake |
 |
| Pit viper |
 |
| Saw Scaled viper |
 |
| Slender coral snake |
Management of snake bite
1. First aid treatment
2. Transport to hospital
3. Rapid clinical assessment and resuscitation
4. Investigations/laboratory tests
5. Antivenom treatment
6. Supportive/ancillary treatment
7. Treatment of the bitten part
8. Rehabilitation
9. Treatment of chronic complications
First aid
§ Delay enry of venom
§ Tourniquet
§ Above knee
§ Above elbow
Useless or Dangerous Methods
§ Making local incisions or pricks at the site of the bite or in the bitten limb
§ Attempts to suck the venom out of the wound
§ Use of snake stones
§ Electric shock
§ Topical instillation or application of chemicals, herbs or ice packs.
Clinical assesment
Vital signs
o pulse
o BP
o Respiration –SBC
Observe
o Bite mark
o Local reaction
o Painful INE
Neurotoxicity
o Ptosis
o Ophthalmoplegia
o Myasthenia like symptoms
o Asses SBC
Haemotoxicity
o Purpura
o Echymosis
o Gingival sulcus bleed
o Hematuria
Capillary leak syndrome
o Puffiness
o Chemosis
o Parotid swelling
Lab. Investigations
Haematological
o Leucocytosis(>20,000-severe envenomation)
o Elevated PCV
o Thrombocytopenia
o Evidence of hemolysis
o Prolonged ct,pt,ptt
o Elevated fdp
Ct > 20 minutes
Sure sign of envonomation
Pitviper > 2 weeks
ECG: bradycardia
ST-Elevation or other way
T-wave inversion
QT Prolongation
Changes due to hyperkalemia
Metabolic
Hyperkalemia
Hypoxemia with resp.ac
Met.ac or lactic ac
Urine
Hematuria,proteinuria,Hburia
Mburia
Renal : ARF -- BU S.Cr S E
CXR : Pulm.edema
Intrapulm.hgs
Pleural effusion
Immuno-diagnosis: by ELISA….
Highly sensitive but specificity inadequate to diff b/w diff species of snakes
Specific management asv
Horse serum
Asv in india
o cobra
o krait
o russel’s viper
o saw scaled viper
1 mi ASV - 0.6mg cobra R viper
- 0.45mg krait S viper
Indication -Systemic Manifestaiton
o Neurotoxicity
o Repeated vomiting
o Haemotoxicity
o Nephrotoxicity
o Cardiotoxicity
o Rhabdomyolysis
Prolonged CT alone
o Pit viper - no
o Snake not identified
Neurotoxic envonomation
o Initial dose 10 - 15 vials
o Reassess
o Improvement 30 -- 60 min
o Repeat 5 vials after 60 -- 90 mins
o Supportive – neostigmine after atropine
Haemotoxic envonomation
Mild CT < 30 mins
Clot size = 50% blood col
Initial dose = 5 vials
Moderate CT > 30 mins
Clots only speckles
initial dose = 10 vials
Severe incoagulable
Initial dose = 15 vials
Repeat ct after 6 – 9 hours
If ct pronged repeat 5- 10 vials
Low dose infusion – following days
Supportive care
o Antibiotics
o Methyl prednisolone
o FFP, fresh blood
o Prevention and rx of hypotension
o prevention of shock
Prevention of arf
· Proper fluid administration
· Correct myocardial dysfunction
· Monitor output bu s.cr se
· Avoid nephrotoxic drugs
· Protein restriction
Management of local reactions
· Bullae - left intact
· Necrosis - debridement
· Compartment syndrome – fasciotomy
· Most comfortable position
Reactions to anti venom
· Anaphylactoid 10 – 90 mins
· Pyrogenic 2 hours
· Serum sickness 5 – 21 days
Bee and wasp sting
· Neurotoxic
· Hemolytic
· Hypersenstising agents - anaph
· Rx local antihistamines
Scorpion sting
· Hemo / neuro toxic
· Sting mark one hole in centre
· Take ecg to r o cardiotoxicity
· Rx local anaesthetic ice pack
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