Bites and Stings. Dr Pavan .M MD(A &EM), VMKVMC. Epidemiology. 3 million bites and 1,50,000 deaths/year from venomous snake worldwide. Bites highest in temperate and tropical regions. 3000 species of snakes, out of them only 10-15% of snakes are venomous
Dr Pavan .M
MD(A &EM), VMKVMC
3 million bites and 1,50,000 deaths/year from venomous snake worldwide.
Bites highest in temperate and tropical regions.
3000 species of snakes, out of them only 10-15% of snakes are venomous
97% of all snake bites are on the extremities
Cobras(nagraj) –Naja naja,N.oxiana, N.kabuthia
Heat-sensing facial pits
(hence the name "pit vipers").
Non Poisonous Snakes
Head - RoundedFangs - Not presentPupils - RoundedAnal Plate - Double row Bite Mark - Row of small teeth.
Head – Triangle
Fangs – Present
Pupils - Elliptical pupil
Anal Plate - Single row
Bite Mark - Fang Mark
Approximately 2500 different species of snakes are known. Approximately
Snake venom is highly modified saliva
Cytotoxic effects on tissues
Toxic dose. The potency of the venom and the amount of venom injected vary considerably.
20% of all strikes are "dry"
Proteolytic enzymeshave a trypsin-like activity.
Hyaluronidase splits acidic mucopolysaccharides and promotes the distribution of venom in the extracellular matrix of connective tissue.
Phospholipases A2-break down membrane phospholipids -causes cellular membrane damage
All these enzymes cause oedema, blister formation and local tissue necrosis
Blocks the stimulus
nerve cell to muscle
and cause paralysis
Does not penetrate
the blood-brain barrier
Postsynaptic effects are reversible with antivenom and neostigmine.
Presynaptic nerve terminal, e.g. beta-bungarotoxin and here neostigmine will not be effective.
Activate prothrombin (e.g. ecarin from Echis carinatus)
Effect on fibrinogen and convert it into fibrin -thrombin-like activity, such as crotalase (rattlesnake venom)
Activate factor 5, factor 10 , Protein C
Activate or inhibit platelet aggregation
Haemmorhagins- cause endothelial damage
(swelling etc) with
Ptosis, external opthalmoplegia, facial paralysis etc and dark brown urine=Russell's viper, Sri Lanka and South India
Local envenoming (swelling etc) with paralysis=Cobra or king cobra
Paralysis with minimal or no local envenoming
Krait, Sea snake
Paralysis with dark brown urine and renal failure: Russle viper
No evidence of envenomation
Suspected snake bite
Fang mark may be present
Pain and 1 inch edema & erythema
No systemic signs- first 12 hours
No lab changes
Fang wound & moderate pain present
1-5 inches of edema or erythema
No systemic involvement in present after 12 hours
No lab changes
Within 12 hours edema spreads to the extremities and part of trunk.
Petechiae and ecchymosis may be generalized
Envenomation very severe
Sudden pain rapidly
Progressive swelling which leads to ecchymosis all over trunk
Bleb formation and necrosis
Systemic manifestations within 15 min after the bite
Blood grouping & cross matching
A few milliliters of fresh blood are placed in a new, plain glass receptacle (e.g., test tube) and left undisturbed for 20 min.
The tube is then tipped once to 45° to determine whether a clot has formed. If not, coagulopathy is diagnosed
Blow up a blood pressure cuff to 80 mm Hg and leave it on for 5 minutes.
If a crop of purpuric spots appears below the cuff, the test is positive.
When to use ASV?
How much to use?
What if a reaction occurs?
When to stop ASV?
Hemostatic abnormalities(lab and clinical)
Progressive local findings
Systemic signs and symptoms
Manufactured by hyper immunizing horses against venoms of four standard snakes
Cobra (naja naja)
Saw scaled viper(Echis carinatus)
Lyophilised form: stored in a cool dark place & may last for 5 years
Liquid form: has to be stored at 4°c with much shorter life span
Each 1ml of reconstituted serum neutralise0.6 mg of naja naja0.45 mg of Bungarus caerulus0.6 mg of V.russelli0.45 mg of Echis carinatus
0.02ml of 1:100 solution of serum is injected sc
A positive reaction occurs within 5 to 30 mins.
Appearance of wheal & surrounding erythema
Adrenaline 0.5 to 1ml IM
If hypotension,severe bronchospasm or laryngeal edema give 0.5 ml of adrenaline diluted in 20 ml of isotonic saline over 20 mins iv.
A histamine anti H1 blocker-chlorpheniramine maleate-10 mg IV
Late reactions-respond to CPM-2 mg, 6 hrly or oral prednisolone-5 mg 6 hrly
Dose should be further diluted in isotonic saline and restarted as soon as possible.
Concomitant IV infusion of epinephrine may be required to hold allergic sequelae at bay while further antivenom is administered
Lab values returns to baseline
Signs of neurotoxicity reverses
Local effects halts progression
Anticholineesterase have variable but useful role
Atropine sulphate 0.6 mg
Edrophonium chloride 10 mg IV (or) Neostigmine: 1.5–2.0 mg IM (children, 0.025–0.08 mg/kg)
If objective improvement is evident at 5 min
continue neostigmine at a dose of 0.5 mg (children, 0.01 mg/kg) every 30 min as needed with
atropine by continuous infusion of 0.6 mg over 8 h -children, 0.02 mg/kg over 8 h
Administration of crystalloid (20–40 mL/kg)
Trial of 5% albumin (10– 20mL/kg)
CVP guided fluids
Inotropic support and invasive monitoring
Oliguria & renal failure- fluids,diuretics, dopamine
no response-fluid restriction- Dialysis
Local infection- TT,antibiotics
Haemostatic disturbances-FFP,fresh whole blood,cryoprecipitates
0.1% adrenaline relieves pain
No need for ASV
If signs of compartment syndrome are present and compartment pressure > 30 mm Hg:
Administer Mannitol 1-2 g/kg IV over 30 min
Simultaneously administer additional antivenom, 4-6 vials IV over 60 min
If elevated compartment pressure persists another 60 min, consider fasciotomy
Honey bee belong
Only the females have adapted a stinger from the ovipositor on the posterior aspect of the abdomen
Melittina–membraneactive polypeptide that can cause degranulation of basophils and mast cells, constitutes more than 50 percent of the dry weight of bee venom
Venom commonly causes pain, slight erythema, edema, and pruritus at the sting site
Toxic manifestation and anaphylaxis
Delayed reaction –Serum sickness
Immediate removalis the important principle and the method of removal is irrelevant.
Sting site should be washed thoroughly with soap and water to minimize the possibility of infection.
Epinephrine 0.3 to 0.5 mg (0.3 to 0.5 mL of 1:1000 concentration) in adults and 0.01 mg/kg in children (never more than 0.3 mg).
Injected IM and the injection site massaged to hasten absorption
If hypotension,severe bronchospasm or laryngeal edema give 0.5 ml of adrenaline diluted in 20 ml of isotonic saline over 20 mins
Observation for 24 hours in ICU
Parenteral antihistamines (diphenhydramine 25 to 50 mg IV, IM, or PO) and H2-receptor antagonists (ranitidine 50 mg IV)
Steroids (methylprednisolone 125 mg) -to limit ongoing urticaria and edema and may potentiate the effects of other measures.
Bronchospasm is treated with -agonist nebulization.
-massive crystalloid infusion, and central venous pressure monitoring may be helpful in these patients.
-Persistent hypotension require dopamine.
-If dopamine isineffective, an intravenous infusion of epinephrine can beused
Every patient who has had a systemic reaction -insect sting kit containing premeasured epinephrine and be carefully instructed in its use.
Patient must inject the epinephrine at the first sign of a systemic reaction.
Medic alert tag
Scorpions have a world-wide distribution.
Highly toxic species are found in the Middle East, India, North Africa, South America, Mexico, and the Caribbean island of Trinidad.
Venom can open neuronal sodium channels and cause prolonged and excessive depolarization
Somatic and autonomic nerves may be affected
Initial pain and paresthesia at the stung extremity that becomes generalised
Cranial nerve- abnormal roving eye movements, blurred vision, pharyngeal muscle incoordination and drooling and respiratory compromise
Excessive motor activity
Nausea, vomiting, tachycardia, and severe agitation can also be present.
Cardiac dysfunction, pulmonary edema, pancreatitis, bleeding disorders, skin necrosis, and occasionally death can occur
Immobilization of limb
Local anaesthetics are better than opiates
Tetanus prophylaxis, wound care and antibiotics
Benzodizepines for motor activity.
Stabilize Airway Breathing and Circulation
Always combination of alpha blocker with beta blocker to prevent unopposed alpha action causing tachycardia
Nitrates for Hypertension/MI
CVP guided fluids
Decrease preload with furosemide (not hypovolumic)
Reduction of afterload improves outcome-Prazosin, nitroprusside, hydralizine, ACE inhibitor
Dobutamine is the best inotrope, avoid Dopamine
Noradrenaline can be used
Insulin has shown to improve cardiopulmonary status in case of scorpion envenomation