This document provides information on snake identification and management of snake bites in Sri Lanka. It discusses the clinical features, epidemiology and management of bites from common snakes in Sri Lanka including Russell's viper, cobra, krait, saw-scaled viper, hump-nosed pit viper and green pit viper. For each snake, it outlines signs of local envenoming, coagulopathy and neurotoxicity. The document provides guidance on airway management, IV fluids, antivenom administration and monitoring for anaphylaxis or other reactions to the antivenom.

1. Dr KTD Priyadarshani
Registrar in Emergency Medicine
Teaching Hospital Peradeniya
2023/03/30

2.  OVERVIEW
 SNAKE IDENTIFICATION
 CLINICAL FEATURES
 MANAGEMENT
 COBRA BITE
 KRAIT BITE
 RUSSEL’S VIPER BITE
 SAW SCALED VIPER BITE
 HUMPED NOSE PIT VIPER
 GREEN PIT VIPER

6.  Airway – maintain
 Breathing
 Adequacy of ventilation
 Weak cough, respiratory muscle paralysis, inadequate ventilation
 Ambu ventilation, intubation
 Circulation
 Iv access- 20 WBCT
 Fluid bolus if needed- 20 ml/kg
 Evidence of envenoming
 Local effects- swelling, blistering, tissue necrosis
 Signs of neurotoxicity- ptosis, external ophthalmoplegia, limb or respiratory muscle paralysis
 Signs of coagulopathy- bleeding tendency, spontaneous bleeding

7. Local effects Coagulopathy Neurotoxicity
Russell’s viper ++ +++ +
Cobra +++ - ++
Krait - - +++
Saw scaled viper ++ ++ -
Hump nosed viper ++ + -
Green pit viper ++ + -
Sea snake - - +/- muscle movement
pain +++

9. Russell’s
viper
Paddy field or foot path, at dawn or dusk, bites on elbow & below, knee
& below
Cobra Close to bodies of water, in & around houses, bites on elbow & below,
knee & below
Krait Victims sleeping on the floor, at night, bites anywhere from head to toe.
A high incidence in the dry zone, September to December
Hump nosed
pit viper
Damp places around dwellings, sheds, in gardens, under leaf filter,
bites on limb extremities
Green pit
viper
Tea puckers & other agricultural workers. Bites on limb extremities
Saw scaled
viper
Sandy, arid coastal plains, Jaffna vegetable farmers, bites on limb
extremities

11. False positive result False negative results
Non glass vessel
Glass vessel cleaned with detergent, soap or
washing fluids
Wet or contaminated glass vessel
Coagulopathy- mild depletion of fibrinogen &
clotting factors
It is recommended that PT/INR should be routinely estimated together with the 20WBCT
whenever possible
If 20WBCT is inconsistent with the clinical picture, aPTT & fibrinogen assay may be performed

14. Indications
 Systemic envenoming
 Local envenoming in cobra bites alone
Premedication
 Adult with no co-morbidies
 S/C adrenaline 0.25 mg (0.25 ml of 1:1000
 Children- S/C 0.005mk/kg of 1:1000
 Antihistamine and hydrocortisone is not advocated for premedication

15. Same dose IV for both adult and children- volume of diluent
can be adjusted
Dose depend on severity of envenoming
 Acute severe coagulopathy following Russell’s viper bite- 30
ampoules as 1st dose & can be repeated in 6 hrs 10 ampoules if
coagulopathy persists
 Cobra & Krait bite- 10 ampules
100-200 ml (10-20 ampoules) or more of Indian polyspecific
antivenom in 400ml of normal saline infused intravenously
over one hour

16. End point
 reversal of coagulopathy- serial 20 WBCT
Neurotoxicity recovers later
Monitor for anaphylaxis
 Pulse, blood pressure & respiration, rash

17. Anaphylaxis
 If reaction occur
 Stop infusion
 Airway & fluid
 IM adrenaline 0.5mg- adult 0.01mg/kg- children in to upper lateral thigh-
vastus lateralis
 Antihistamine & corticosteroids- not recommended
 Bronchospasm- inhaled salbutamol or terbutaline
 Refractory shock
 Adrenaline infusion (1mg- 250 ml 1-4 microg/min to max 10 microg/min)
 Dopamine

18. Pyrogenic ( endotoxin ) reactions
 1-2 hrs after treatment- Commonly reported
 Symptoms
 Shaking chills( rigors)
 Fever
 Vasodilatation & hypotension
 Febrile convulsions in children
 Pyrogen contamination during the manufacturing process
 Management
 External cooling- remove clothes, tepid sponging
 Antipyretic- paracetamol
 Iv fluids
 If features of anaphylaxis- give adrenaline

19. Late ( serum sickness type) reactions
 1-12 days (mean 7) days after
 Fever, nausea, vomiting, diarrhea,
 itching, recurrent urticaria,
 arthralgia, myalgia, lymphadenopathy,
 periarticular swelling, mononeuritis multiplex,
 proteinuria with immune complex nephritis,
 encephalopathy
 Early reaction & treated with antihistamine & corticosteroid- less likely to develop late
reactions
 Course of oral antihistamine 5 days ( chlorpheniramine 2mg 6 hrly)
 If fail to respond with in 24-48 hrs- give a course of prednisolone 5 days (5mg 6hrly)

20. Naja Naja
Epidemiology
• More females (13-70 yrs)
• In day time (6am-6pm)
• 50% bites with in victim’s home nearby
• More bites to the LL
Clinical manifestations
• Majority- local reactions
• Neurotoxicity
• Transient coagulopathy with positive 20 WBCT

21. Management
• Antivenom for local envenoming
alone- 10 ampoules
• Neurotoxicity- observe for
respiratory paralysis
• Surgical referral for local reactions
• Positive 20WBCT with no signs of
bleeding- spontaneous resolution

22. Common/ Indian krait (Bangarus caeruleus)
Ceylon krait (Bangarus Ceylonicus)
Epidemiology
 Seasonal variation – common during September to
December
 In dry zone during rainy days
 At night Sleeping on the floor of incompletely built houses &
huts
 Bite site could be anywhere- minimal pain, local effects &
unnoticed
 25%- DRY BITES

23. Clinical features
Local envenoming
 Swelling & pain- minimal
 Numbness- rare
Systemic envenoming
 Abdominal pain- nonspecific
 Neuromuscular paralysis
 Progress sequentially in descending
order
 Respiratory paralysis- 8hours
 May last 1 day to weeks
 Resolves in reverse order
 Autonomic effects

24. Management
Admit & observe 24 hrs
Antivenom 10 ampoules
Neurotoxic signs
Severe abdominal pain without paralysis
Neuromuscular effects
TV <250ml- mechanical ventilation
Bulbar paralysis- intubate

25. Epidemiology
• Majority of fatal snake bites in sri
lanka
• Day time ( 6am-6pm) towards dusk
and early hours of night
• On foot paths, roads and home
gardens
• daytime- paddy fields
• Males (10-40 years)

26. Clinical manifestations
• Dry bites- not common
• Local effects
• Severe pain
• Oozing
• Local swelling
• Coagulopathy
• Prolonged PT/INR, aPTT
• Depleted clotting factor levels
(fibrinogen, factor V & X)
• Systemic bleeding- hematuria, gum
bleeding, hematemesis,
• Acute kidney injury
• Neurotoxicity
Management
 AVS 20 ampoules
 Repeat test of 20WBCT in 6 hours – if
still positive repeat antivenom dose of
10 vials
 AKI
 May need dialysis
 Coagulopathy
 FFP after AVS ( Ibsister et al) No effect
in SL

27. Epidemiology
• In dry and sandy costal plains
• North western, northern, eastern, Sothern
province
• Bites are usually on the fingers, foot and toes
Clinical features
• Local swelling
• Blistering and necrosis
• Spontaneous bleeding
• AKI- rare
Management
• Antivenom therapy- 10 ampoules

28. Epidemiology
• Widely distributed, commonly found in
coconut, rubber & tea plantations
• In evening hours
• Most bites in extremities- fingers, toes
& feet below the ankles

29. Clinical features
• Nonspecific
• Abdominal pain
• Nausea & vomiting
• Faintishness
• Fever
• Headache
• Local envenoming -80%
• Local pain, swelling
• Necrosis at bite site
• Hemorrhagic blisters
• Regional lymphadenopathy
• Systemic manifestations- mortality
• VICC
• AKI (10%) – ATN, FSGS< Cortical necrosis, interstitial nephritis

30. Management
 Observe all for 48 hrs
 20 WBCT 6 hourly for 48 hrs
 Hydrate
 Pain
 Paracetamol 1g 6H or Tramadol 50 mg bd
 Elevate affected limb
 Monitor for compartment syndrome
 Cellulitis or local sepsis
 IV/O Floxacillin 500mg 6H
 O Metronidazole 400mg 8H
 Wound debridement
 Currently available Indian polyvalent antivenom is ineffective
 IM tetanus toxoid at discharge

31. Epidemiology
• Distributed in wet zone- tea, cinnamon, coffee
plantations
Clinical manifestations
• Local envenomation (91-94%)
• Systemic envenoming – potentially life threatening-
no reported
• Venom induced consumption coagulopathy
(VICC)
• Polyuria renal failure
• ECG changes- ischemia, bradycardia
• Ptosis

32. Investigations
• FBC with blood picture
• PT/INR, aPTTT
• BU, S creatinine
• SE
• ECG
Management
• Elevate limb
• 20WBCT- admission & repeat 6
hourly for 24 hours ( if positive
persistently- continue for 48 hrs)
• Coagulopathy (20WBCT &
PT/INR) – FFP 10 ml/kg/day- 2
days
• Wound toilet & dressing. Monitor
for compartment syndrome- early
surgical referral
• Fluid IV/ O 100 ml/hr
• If UOP <0.5ml/kg/hr- IV
Frusemide 20mg bolus can be
given
• Pain
• Paracetamol 1g – 6hrly
• Tramadol 50 mg bd
• Antibiotics
• IV Cloxacillin 500mg 6 H
• IV coamoxiclave 1.2 g 8H
• IV Clindamycin 300mg 8H
• Tetanus toxoid on discharge