Snake bite and it's management

1. SNAKE BITE AND ITS
MANAGEMENT
Guided by – Dr. Nilay Mozarkar
(DNB Pediatrics)
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Presented by – Dr. Peetamber
Patel

2. OBJECTIVES
 Introduction
 Pathophysiology
 First aid
 Sign & Symptoms
 Lab investigation
 ASV
 Management
 Recovery
 Discharge
 Summary
 Reference
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3. INTRODUCTION
 Snake bite is acute life threatening time limiting medical emergency
 >2000 species of snake in world
 300 species found in India which 52 are venomous
 3-4 million snakebites annually in India
 ≈58000 deaths/year in India. which accounts half of snake bite death
globally.(NCDC 2022)
 50% in age group of 30-69
 25% in age group of <15 year
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4. Snake bites
70% by non-
poisonous snakes
30% by poisonous
snakes
50% dry
bites
50% poison
is injected
Mild
envenomation
Moderate or
severe
envenomation
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5. POISONOUS SNAKES IN INDIA
 The big 4
 Elapidae - 1. Kraits (Bungarus)
2. Cobras (Naja)
 Viperdae - 3. Russell’s viper(Daboia)
4. Saw-scaled vipers(Echis)
Kraits (Bungarus)
Cobras (Naja)
Saw-scaled vipers(Echis)
Russell’s viper(Daboia)
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6. Elapidae Viperidae
Long, thin usually uniformly-colored
Large smooth symmetrical scales on top
of the head
Cobras, raise the front part of their body
off the ground and spread hood
Short, thick-bodied, short-tailed
Many rough scales on the top of head
Characteristic patterns of colored marking
on their back
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7. Elapidae Viperidae
Fangs are mounted on relatively fixed
maxilla at front of mouth
Fangs are mounted on rotatable maxilla
so that they can be folded flat against the
roof of mouth
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8. PATHOPHYSIOLOGY
 >100 different types of toxic and nontoxic proteins and peptides
 Also contain nonprotein, carbohydrates, lipids, amines, and various small
molecules
 Venom composition is exclusive to each species only
 Neurotoxins – venom of elapids
 Cytotoxic and anticoagulant/procoagulant – vipers
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9. Cytotoxic enzymes
Phospholipases A2
metalloproteinases
Release of other
inflammatory
mediators
Pain at bite site
Bradykinin, prostaglandin,
cytokines,
sympathomimetic amines
Edema, blister & tissue
necrosis
Activate pro-
inflammatory pathway
Peptides
Inhibition of
ACE
Hypotension
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10. Neurotoxin
Curare like action
i.e. binding to AChR
at NMJ
Postsynaptic
α-neurotoxin
(three finger protein
complex, irditoxin)
Prevent release of
Acetylcholine at
NMJ
Presynaptic
β-neurotoxins
(taipoxin, paradoxyn,
crotoxin)
Muscle paralysis
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11. FIRST AID
 Do RIGHT
 Keep affected limb below the level of heart while transporting
 Do not use tight tourniquet, single finger insert test
 Do not give cuts or suck wound
 Do not give local ASV
 Do not use herbs, ice packs, and snake stones
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12. Sign & Symptoms
 Asymptomatic
 Neurotoxic /Neuroparalytic
 Vasculotoxic /Haemotoxic
 Myotoxic
 Painful progression of swelling
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13. Asymptomatic
 Non specific symptoms related to anxiety
 Palpitation
 Sweating
 Tachycardia, Tachypnea
 Elevated blood pressure
 Cold extremities and paresthesia
 May develop vasovagal shock
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14. NEUROPARALYTIC
 Cobra bite – 30min-6hrs
 Krait – 6-12hr
 2 P’s
 Ptosis (Drooping of eyelid)
 Paralysis (intercostal & Skeletal muscles)
 5 D’s
 Diplopia (Double vision)
 Dysarthria (Speech difficulty)
 Dysphonia (Pitch of voice become less)
 Dyspnea (Breathlessness)
 Dysphagia (Inability to swallow)
 Additional features like stridor, ataxia may also be seen
 Associated hypertension & tachycardia may be present due to hypoxia
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15. Impending respiratory failure
1. Single breath count – number of digits counted in one exhalation - >30
2. Breath holding time – breath held in inspiration - >45sec
3. Ability to complete one sentence in one breath
 Cry in child whether loud or husky can help in identifying impending
respiratory failure
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16. VASCULOTOXIC / HAEMOTOXIC
 Viper species
 Local manifestation
 Systemic manifestation
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17. Local manifestation
 More prominent in Russel’s viper > Saw scaled viper
 Local swelling, bleeding, blistering & necrosis
 Pain at bite site
 Severe swelling leading to compartment syndromes
 Tender enlargement of local draining lymph nodes
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18. Systemic manifestation
 Visible systemic bleeding from the action
of haemorrhagins
 Gingival bleeding
 Epistaxis
 Hematemesis
 Hemoptysis
 Sub-conjunctival hemorrhages
 Continue bleeding from bite site
 Bleeding or ecchymosis at the injection
site
 Acute abdominal tenderness may
suggest gastro-intestinal or retro-
peritoneal bleeding
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19. Life threatening complications
 Acute kidney injury(AKI) – Russell’s viper(Daboia sp)
 Declining or no urine output
 Deteriorating renal signs- ↑ serum creatinine, urea or potassium
 B/L renal angle tenderness, albuminuria, hematuria, hemoglobinuria,
myoglobinuria, f/b oliguria, anuria with AKI
 Hypotension due to hypovolemia or direct vasodilatation aggravates AKI
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20. MYOTOXIC
 Common in Sea snakebite
 Muscle aches, muscle swelling, involuntary contraction of muscles
 Passage of dark brown urine
 Compartment syndrome, cardiac arrhythmias due to hyperkalemia
 Acute kidney injury due to myoglobinuria
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21. PAINFUL PROGRESSIVE SWELLING(PPS)
 Prominent in Russel’s viper bite, Saw scaled viper bite and Cobra bite
 Local necrosis which often has a rancid smell
 Limb is swollen and the skin is taut and shiny. Blistering with reddish black
fluid at and around the bite site. Skip lesions around main lesion are also
seen
 Ecchymosis due to venom action destroying blood vessel wall
 Significant painful swelling potentially involving the whole limb and
extending onto the trunk
 Compartment syndrome will present invariably
 Regional tender enlarged lymphadenopathy
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22. LAB INVESTIGATIONS
 Bedside 20 minute whole blood clotting test (20 WBCT)
20 WBCT
Then every 6
hours for 24 hours
ASV
Recheck hourly for
3 hours
Blood doesn’t clot
Blood clots(if
suspecting viper
bites)
Repeat every 6
hours
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23.  Urine dipstick – albumin
 BUN/Creatinine – AKI
 Total counts – neutrophilic leukocytosis
 Electrolytes – Hyperkalemia
 INR – coagulopathy
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24. Approach to a pt. with snake bite
 Confirm snake bite
 Assess hemodynamic stability
 Rapid detail history
 Lab work
 Fang marks
 Assess signs & symptoms of
envenomation
 Yes → ASV
 No → Monitor pt. closely every 1 hr for ↑ in
swelling, Bleeding/20 WBCT, neuroparalysis
→ keep ↓ observation for 24 hrs
venomous
European adder
venomous Western
Russell’s viper
non-venomous water
snake rat
catfish
Brazilian wandering spider
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25. ASV
 Polyvalent ASV – Neutralizes (big 4)
 Each vial neutralize 6mg of Russel’s Viper
venom
 Give only by IV, do not give IM
 The dose of ASV for children is the SAME as
that adult
 No contraindication to ASV including
pregnancy
 No test dose required
 Typical total dose of ASV – 10-25 vials
 Before starting ASV draw adrenaline in
syringe keep it by bedside
 Keep hydrocortisone and chlorpheniramine
injections ready
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26. Give 0.25mg(children 0.005mg/kg) of 0.1% adrenaline SC
Reduce risk of anaphylaxis 40%
Consider pt – 15-60yrs
C/I – Hypertensive
Monitor BP – every 5 min for
30 min then 15min for 2 hrs
After ASV monitor vitals every
1 hour
Monitor UOP
Give 500ml ASV solution over
30-60 min
Start ASV initially slowly
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27. ASV DOSE
 For Neuroparalytic snakebite – 10 vials stat over 30min → 2nd dose of 10
vials after 1 hour if NO improvement within 1st hour
 For Vasculotoxic snakebite –
 Low dose infusion therapy – 10 vials stat over 30min → 2 vials every 6 hours
as infusion in 100ml NS till clotting time normalizes or for 3 days whichever is
earlier
 High dose intermittent bolus therapy – 10 vials stat over 30min → 6 vials 6
hourly as bolus therapy till clotting time normalizes and/or swelling subsides
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28. ADVERSE ASV REACTIONS
Early anaphylactic reaction:
• 10 min – 6 hrs post-ASV
• Starts with urticarial, irritability, abdomen pain
and tachycardia
• Progresses to cause hypotension, angioedema,
and shock
• Stop ASV
• Administer adrenaline 0.01mg/kg (1 in1000
dilution) IM
• Repeat every 5-10min if symptoms persist
• Chlorpheniramine malate(0.2mg/kg IV) and
hydrocortisone(2-5mg/kg IV) can be added
• ASV should be restarted slowly after clinical
stabilization
• Persistent shock – NS bolus and ADR infusion can
be given
Pyrogenic reaction:
• 1-2 hours after ASV
• Include fever, chills and rigors
• Caused by pyrogenic contamination during ASV
manufacturing
• Paracetamol and other cooling
procedures(sponging, fanning)
• No need of stopping ASV
Late(serum sickness like) reaction:
• Develop 1-2 days post ASV
• Fever, vomiting, recurring urticarial, arthralgia,
myalgia, lymphadenopathy, nephritis
• Prednisolone (0.7mg/kg/day) for 5-7 days
• With or without oral chlorpheniramine
maleate(0.25mg/kg/day)
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29. MANAGEMENT OF NEUROTOXIC
ENVENOMATION
 Oxygen
 Assisted ventilation
 Administer Atropine Neostigmine (AN) in cobra bite
 Do not give AN in case of confirmed krait bite
 Krait bite – affects pre-synaptic fibers where calcium ion act as
neurotransmitter
 Inj. Calcium gluconate 10ml IV(children 1-2ml/kg)(1:1 dilution) slowly over 5-
10min every 6 hourly
 Continue till neuroparalysis recovers
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30. IV Atropine0.6mg(children 0.05mg/kg) followed by IV
Neostigmine 1.5mg(children 0.04mg/kg)
IV Atropine0.6mg(children 0.05mg/kg) followed by IV
Neostigmine 0.5mg(children 0.01mg/kg)
Stop if NO response, continue 2 more doses if pt is
responding
IV Atropine0.6mg(children 0.05mg/kg) followed by IV
Neostigmine 0.5mg(children 0.01mg/kg)
30 min
30 min
30 min
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31.  After 5 dose tapering dose at 1 hour, 2 hour, 6 hour and 12 hour
 Positive response to ‘AN’ trial – 50% or more recovery of the ptosis in one
hour
 Stop AN if
 Complete recovery from neuroparalysis
 Side effect in form of fasciculations or bradycardia
 No improvement after 3 dose
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32. MANAGEMENT OF VASCULOTOXIC
SNAKEBITE
 Strict bed rest
 Screen for hematuria, hemoglobinuria, myoglobinuria by dipstick method
 Monitor UOP and maintain 1ml/kg UOP
 In intravascular volume depletion
 Indicated by supine or postural hypotension, or empty neck veins
 Give fluid challenge – 200ml NS in 5 min, check BP response if positive
additional fluid given over 30 min
 Until JVP has risen to 8-10cm above sternal angle
 Stopped immediately if pulmonary edema develops
 Manage shock – bolus, inotropes
 For coagulopathy prolonged CT, PT, aPTT - FFP
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33. Forced alkaline diuresis (FAD)
 If UOP does not improve
 Or dipstick positive for blood
 Give trial of FAD Within 24 hours of bite
 UOP 3ml/min is expected
 If responds to first cycle continue for 3 cycle
 Convert oliguria to polyuria and avoid ATN &
AKI
 If no response to furosemide refer for dialysis
Inj Furosemide 40mg IV
stat
IV NS 500ml + 20ml NaHCO3
over 20 min
IV RL 500ml + 20ml NaHCO3
over 20 min
IV NS 500ml + 10ml of KCl
over 90 min
IV Mannitol 150ml over 20 min
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34. MANAGEMENT OF SEVERE LOCAL
ENVENOMING
 Surgical intervention in case of local necrosis, intracompartmental
syndromes
 Prophylactic broad-spectrum antimicrobial treatment for cellulitis
 Inj. Amoxyclav 1.2gm IV TDS (children 100mg/kg/day) or
 Inj. Ceftriaxone 1gm BD (children 100mg/kg/day)
 Inj. Metronidazole 400mg IV TDS (30mg/kg/day)
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35. RECOVERY PHASE
 After receiving appropriate ASV
 Swelling takes weeks to resolve despite receiving ASV
 Coagulopathy –
 Spontaneous systemic bleeding stop 15-30 min
 Blood caogulability is usually restore in 6 hours
 Neuroparalysis – usually resolve in few days after ASV
 Postsynaptic neurotoxic envenomation – 30 minuets to several hours
 Presynaptic neurotoxic envenomation – considerable time to improve
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36. DISCHARGE
 After 24 hour if no symptoms and signs develop
 Keep ↓ observation for 48 hours if ASV was infused
 Follow-up
 Rehabilitation – for normal function of the bitten limb
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37. Summary of clinical features of different
snakebites
Feature Cobra Common
krait
Russell’s
viper
Saw-scaled
viper
Local pain/tissue
damage
YES NO YES YES
Ptosis/neurotoxicity YES YES YES* NO
Response to
neostigmine
YES NO NO NO
Hemotoxicity NO NO YES YES
Renal complication NO NO YES NO
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38. REFERENCES
 World Health Organization Guidelines For Management Of Snake Bites(2nd
Edition),2016
 Ministry Of Health And Family Welfare, Government Of India, Standard Treatment
Guidelines, Management Of Snake Bite, 2017
 IAP Standard Treatment Guidelines 2022. Snakebite
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39. THANK YOU
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