Snakebite & ASV Management ProtocolIndian National Snakebite Protocol (MoHFW 2016), WHO SEARO Guidelines & NAPSE 2022
Clinical Syndrome on Presentation ?
20-Minute Whole Blood Clotting Test (20WBCT) ?
Severity & Complications ?
Patient Category
Envenoming Syndrome
-
-
ASV Indication
-
-
ASV Administration Protocol
Monitoring & Adjunctive Care
⚠ ASV Reaction Preparedness
◆ Evidence-Based PearlsIndia's Snakebite Burden
⚠ Sobering Data: India reports an estimated 58,000 snakebite deaths annually. This is ~46% of global snakebite mortality. India has 310+ snake species; 66 are venomous, but 90% of envenoming is caused by only 4 species: the "Big Four."
WHO NTD Status: Snakebite envenoming was recognised as a Neglected Tropical Disease (NTD) by WHO in 2017.
Seasonality: Peak incidence during monsoon (June to September).
Krait Nocturnal Bites: ~65.7% of snakebite deaths are from Common Krait, which bites sleeping victims at night. The bite is often painless and may go unnoticed.
Venomous vs Non-Venomous Snakes: Key Differentiators
⚠ Clinical Pearl: These morphological features are NOT reliable for clinical decision-making. Treat based on clinical syndrome, NOT on snake identification.
Feature
Typically Venomous
Typically Non-Venomous
Head shape
Triangular (Vipers); may be rounded (Elapids)
Usually rounded or oval
Pupil
Vertical slit (Vipers); round (Elapids)
Round
Fangs
Two prominent fangs
Rows of small, uniform teeth
Bite marks
1-2 puncture marks, spaced apart
Multiple small tooth marks (horseshoe pattern)
The "Big Four" Venomous Snakes of India
💡 Key Fact: Indian polyvalent ASV is manufactured using venoms of these 4 species. It does NOT cover Hump-nosed Pit Viper (Hypnale hypnale), Banded Krait, or King Cobra.
1. Indian Spectacled Cobra (Naja naja)
Venom Type
Neurotoxic (post-synaptic) + cytotoxic
Clinical Signature
Rapid onset ptosis, descending paralysis, respiratory failure. Painful bite with severe local necrosis.
2. Common Krait (Bungarus caeruleus)
Venom Type
Neurotoxic (pre-synaptic; responds poorly to neostigmine)
Clinical Signature
Painless bite. Delayed onset paralysis, colicky abdominal pain. Very high mortality rate due to respiratory failure in sleep.
3. Russell's Viper (Daboia russelii)
Venom Type
Haemotoxic + nephrotoxic (South Indian variants add neurotoxicity)
Clinical Signature
Extremely painful bite. Non-clotting 20WBCT, systemic bleeding, DIC, AKI, and profound local swelling.
4. Saw-Scaled Viper (Echis carinatus)
Venom Type
Haemotoxic (potent pro-coagulant)
Clinical Signature
Severe coagulopathy, spontaneous bleeding. The snake makes a distinctive "sizzling" warning sound.
20-Minute Whole Blood Clotting Test (20WBCT)
💡 Gold Standard Bedside Test: Highly specific (91%) for detecting coagulopathy. Requires NO laboratory equipment.
Step 1: Collect 2 ml of freshly sampled venous blood.
Step 2: Place in a NEW, CLEAN, DRY glass tube. Do NOT use plastic tubes or injection vials.
Step 3: Leave UNDISTURBED for exactly 20 minutes.
Step 4: After 20 minutes, gently tilt the tube once. Do NOT shake.
Result: Blood runs out = POSITIVE. Firm clot = NEGATIVE.
ASV Dosing: Indian National Protocol
⚠ Paediatric Principle: ASV dose neutralises venom load, NOT body weight. A child receives the SAME dose as an adult.
Syndrome
Initial (Loading) Dose
Maximum
Haemotoxic
10 vials in 200 ml NS IV over 1 hour
25-30 vials
Neurotoxic
10 vials in 200 ml NS IV over 1 hour
20 vials
ASV Adverse Reaction Management
Reaction Type
Timing
Management
Anaphylaxis
Mins to 1 hr
Inj. Adrenaline 0.5 mg IM. Stop ASV temporarily. IV Hydrocortisone 200 mg. IV Chlorpheniramine 10 mg. Restart ASV slowly.
✓ Premedication: Low-dose SC Adrenaline (0.25 mg) given 5 minutes before ASV reduces early adverse reactions.
Neurotoxic Management: The Neostigmine Test
Protocol: Inj. Atropine 0.6 mg IV, followed by Inj. Neostigmine 1.5-2.5 mg IV.
Positive response: Improvement in ptosis within 30-60 mins suggests post-synaptic blockade (Cobra). Continue maintenance.
Regional Considerations: Coastal Karnataka & South India
Hump-nosed Pit Viper (Hypnale hypnale): Common in coastal Karnataka. Causes AKI and coagulopathy. Indian polyvalent ASV does NOT neutralise its venom. Management is strictly supportive.
South Indian Russell's Viper: Unique variant that causes both profound coagulopathy AND neuromuscular paralysis (ptosis).
Olive Keelback: Non-venomous but extremely common near Udupi water bodies. Frequently mistaken for venomous species resulting in panic.
Abbreviations: ASV (Anti-Snake Venom) · 20WBCT (20-Minute Whole Blood Clotting Test) · NS (Normal Saline) · IV (Intravenous) · IM (Intramuscular) · SC (Subcutaneous) · DIC (Disseminated Intravascular Coagulation) · AKI (Acute Kidney Injury) · VICC (Venom-Induced Consumption Coagulopathy) · NAPSE (National Action Plan for Snakebite Envenoming)
Algorithm References & Evidence Base
Ministry of Health and Family Welfare, Government of India. National Snakebite Management Protocol. Standard Treatment Guidelines. NHM; Updated 2016.
World Health Organization, Regional Office for South-East Asia. Guidelines for the Management of Snakebites. 2nd ed. WHO SEARO; 2016.
National Centre for Disease Control (NCDC). National Action Plan for Prevention and Control of Snakebite Envenoming (NAPSE). Government of India; 2022.
Indian Academy of Pediatrics (IAP). National Treatment Guidelines: Snake Envenomation. NTG-005. IAP; 2023.
How to Cite This Tool
AMA Style:
Umakanth S. Snakebite & ASV Management Protocol. MEDiscuss. Published 2026. Accessed .
Vancouver Style:
Umakanth S. Snakebite & ASV Management Protocol [Internet]. MEDiscuss.org; 2026 [cited ]. Available from:
