• Poison: any substance which produces adverse effects in a living organism

• Important cause of morbidity and mortality in India

• Exact estimate not available

• Hospital studies- up to 10% of admissions in medical emergency

• OP & carbamates- ~ 50% of these

• Other compounds- Alphos, methanol, hypnotics and sedatives, TCAs etc

• Urban areas- hypnotics and sedatives, TCAs • Rural areas- Insecticides and Alphos• Methanol- Hooch tragedies, where ever they

occur• Accidental poisoning- common in younger

children• Suicidal intent- teenagers, adults

• Accurate history- may be difficult

• Type of poison, amt ingested/exposed to, time interval b/w exposure & treatment

• Suspect when there is unexplained, sudden illness in a healthy individual, h/o psy illness, h/o strained relationship, onset of illness while working with insecticides, chemicals or after ingestion of food.

• Quick, careful initial assessment to assess

the need for immediate supportive care

• Certain characteristic features in some

• Coma- Narcotics, Benzodiazepines, barbiturates, alcohol etc

• Delirium- atropine, Datura, LSD, amphetamines, cocaine, alcohol

• Cyanosis- MethHb eg nitrates, CO, Aniline

• Jaundice- PCM, Phosphorus, ATT, EDB

• Cherry red skin- CO

• Bullous rash- barbiturates

• Breath odour- OP, ethanol, Alphos

Management …• General principles

– Pretoxic phase- prior to onset of poisoning• Decontamination- top priority• Treatment- solely based on history• Maximum potential toxicity based on greatest

possible exposure should be assumed• Establish IV access, cardiac monitoring esp

with unclear history and potentially serious ingestion

• Toxic phase- time b/w onset of poisoning and peak effect– Based primarily on clinical exam & lab findings– Effects of overdosage begin sooner , peak later

& last longer than they do after therapeutic dose– Resusc & stabilization- top priority– Decontamination as started in pretoxic phase

• Initial therapy-– Support to vital functions

• Decontamination-– Skin- removal of clothing, thorough wash– Gastric-

• Emesis- effective upto 3-4 hrs of ingestion, only in fully conscious

• Physical stimulation of pharynx, NaCl(200-400 ml fully saturated), ipecac(10-30ml)

• Gastric lavage– Wide bore NG tube– First aspirate to be saved for chemical analysis– 3-5L of tap water ( 200-300ml aliquots)– C/i- corrosives, petroleum distillates

• Activated charcoal– To prevent further absorption– dose- 10 times the dose of poison or as much as

possible if dose unknown (50 gm q 2-6 hrly)

Prevention of recurrence– ~10% of pt with unsuccessful suicidal

attempt are sufficiently depressed and make another attempt

– Psy counselling, social factor exploration

SNAKEBITE

IntroductionIn the world

3000 species, 500 poisonousIn India

216 species, 52 poisonous

Annual mortality in India5.6 to 12.6 per 100000

Venomous Snakes in IndiaElapidae

CobraCommon Krait

ViperidaeRussell’s viperSaw-scaled viper

CrotalidaePit viper

HydrophidaeSea snakes

Recognition of Poisonous snakes1. Fangs

2. Head

3. Pupils

4. Belly scales

5. Body design

Cobra

Russell’s viper

Saw-scaled viper

Krait

Snake VenomCommon components

Procoagulant enzymes

Haemolytic toxins

Cytolytic / necrotic toxins

Myolytic toxin

Pre-synaptic neurotoxin

Post-synaptic neurotoxin

Snake venomsCobra Krait Viper Sea

snakeR

SS

Local effect ++ - +++ -Vasculotoxic - - +++ -Neurotoxic +++ +++ - ++

Cardiotoxic ++ ++ - +Myotoxic - - - +++Dose/bite (mg) 200 22 15

04.6

Fatal dose (mg) 120 60 150

80

Clinical FeaturesDry bites

20% pit viper and 43% cobra bitesLocal features

Fang marksPainSwellingBlistering & necrosisLymphangitis, lymphadenopathyVenom ophthalmia Secondary infection

Local effects of pit-viper bite

Local effects of a viper bite

General features

Flushing

Sweating

Breathlessness, palpitation

Tightness in chest

Nausea, vomiting (in all severe envenoming)

Acroparaesthesiae

Hyper salivation, blurring of vision (cobra)

Abdominal colic, diarrhoea, collapse ( krait)

Systemic Features – Elapid / Krait biteNeurotoxicity• Onset as early as 15 min with ptosis & external ophthalmoplegia• Rapid descending paralysis• Life-threatening respiratory paralysis • Effects completely reversible with antivenin /

anticholinesterases• Spontaneously wears off in 1 – 7 daysCardiotoxicity• Direct myocardial toxicity

Systemic Features – Viper biteClotting defect & haemolysis• Persistent bleeding from puncture sites

• Spontaneous systemic bleeding (gingival sulci commonest site) #

•NephrotoxicityCommonest with Russell’s viperCause - hypovolemia & ischaemia

Systemic Features – Sea snake biteMyotoxicity• Pain & tenderness in muscles develop 0.5

to 3.5 hours after bite• Trismus common• RhabdomyolysisNephrotoxicityNeurotoxicity

Generalized flaccid paralysisCardiotoxicity

Management First aid• Reassure• Immobilize• Move to hospital as soon as possible• Tourniquet / pressure immobilization

in severe elapid envenoming(to delay onset of respiratory paralysis)remove only after 1st dose of antivenin

• Treat shock with colloids• Maintain patent airway

Pressure immobilization

Evaluation in hospital • Look for fang marks• Monitor vitals, local swelling & muscle weakness hourly • Look for bleeding• Platelet count q 12 h • 20 min WBCT , PT, FDP q 6h• Serum electrolytes q 6 h• LFT, RFT, CPK, ECG daily• Monitor urine output, myoglobinuria

Antivenin Lyophilized, polyvalent equine anti - serumEffective against cobra, common krait, Russell’s viper & saw-scaled viperDilute in 10ml of DW, then mix with 5ml / kg of NS / 5% DGive slow i/v over 1 – 2 h

DoseFor viper bitelocal swelling, no systemic signs 50mlmild systemic signs 50 – 100 mlsevere poisoning 150 – 200ml

For cobra bite 100 – 200ml

Response to antivenin• Rapid & dramatic

• Neurotoxic signs may improve within 30 minspontaneous bleeding stops in 15 – 30 min

• Repeat antivenin q 6 h till progression of paralysis stops / clotting profile normalizes

• Adverse reactions: early, pyrogen, & late

Supportive therapy

• Tetanus prophylaxis

• Antibiotics in severe local envenoming

• Fasciotomy for compartment syndrome

• Respiratory paralysis managed with assisted ventilation, Neostigmine & Atropine

• FFP, cryo-precipitates & platelet concentrate for haemostatic disturbances

Avoid

Arterial tourniquetIncision and suctionElectric shockCryotherapyLocal heatCorticosteroids, EDTA, Heparin

Thank you