Dr. Hira Shoaib Hashmi Lecturer, Dept. CHS

SNAKE BITE AND ITS

MANAGEMENT

OBJECTIVES

To know the difference between poisonous and non poisonous snakes.

To know how to manage a patient with snake bite.

To learn how to prevent snake bite.To know the areas in Pakistan where snake bite

is prevalent.

TYPES OF SNAKES

At least 421,000 envenomings and 20,000 deaths from snakebites occur each year, especially in South and South East Asia and sub-Saharan Africa.(1)

3000 speciesBroadly Divided into:

Poisonous SnakesNon Poisonous Snakes

WHAT IS VENOM?It is toxic saliva produced by parotid glands of snakes mostly water

with enzymatic proteins.

ConstituentsProteinasesFibrinolysinPhospholipase A,B,C & DNeurotoxinsCholinesterasesHaemolysins etc.

Produced from the time of birth and injected in response to a prey or self defense

One in five snake bites are dry.

More venom injected when attacking prey.

SNAKE BITE IN PAKISTANA major public health problem because:

Agricultural country-70% population lives in rural areas and works in fields

Lack of basic educationSnakes abundantWeather conditions favorablePeak incidence: June to August• Due to floods and rain with migration to highlands• Sleeping outside in summers• Monsoon season is breeding season• Snake cold blooded more active in summers• Venom yield high in summers

Common in agricultural fields, Thar and Baluchistan.

WHAT IS…….?Haemotoxic Venom:

Attacks blood vessels, serum escapes into surroundings, clotting factors are activated. Severe swelling, pain and discoloration and shock ensues with DIC.

Neurotoxic venom:Much less local symptoms, affects remote

nerves, cause tingling, drooping of eyelids and respiratory arrest.

Myotoxic Venom:Affects muscles with stiffness and paralysisAppearance of myoglobin in urine

DIFFERENCE BTW POISONOUS AND NON POISONOUS SNAKES

SIGNS AND SYMPTOMS

COBRA BITELOCAL S/S:

Considerable pain and swelling usually followed by necrosis.

SYSTEMIC S/S:PtosisGlossopharyngeal nerve paralysisDryness of throatCold clamy extremeties and sweatingRapid pulseHypertensionDeath due to resp. paralysis.

KRAIT BITEMild Local painMild SwellingMuscle Weakness

SEA SNAKE BITE Sharp initial prick afterthat painless

Stiffness in the muscles of back,neck and proximal part of limb in one hour.

VIPERIDAE BITE LOCAL S/S:

Swelliing around the bite site within minutes Severe pain at the bite site Blisters Discolouration

SYSTEMIC S/S: Hematemesis Hemorrhage Haematuria Epistaxis Malena

DIAGNOSIS Finding fang marks S/S Lab Tests on aqueous washings from the bite site:

Cholinesterase-Elapid Bites Thromboplastin-Viper bite

Hyperkalemia on ECG – Sea Snake bite Prolonging of CLOTTING and BLEDDING TIME

IMMEDIATE/GENERAL MEASURES:Allay anxiety and fright as death may occur due to

shock ensuing from fearBed RestGIVE FIRST AID

ImmobilizationTorniquet application between the bite site on the limb and

heart admitiing to two fingers so that arterial flow is not occluded.

Remove torniquet for one minute after every 30 minsIf bite on face neck or trunk, apply firm pressureAcquire aseptic measures to avoid microbial contamination

of bite siteCUT AND SUCK METHODCOLD PACK METHODELECTROSHOCK TREATMENTAUSTRAILIAN PRESSURE TECHNIQUE

FIRST AID

SPECIFIC TREATMENTGIVING POLYVALENT ANTIVENIN

THERAPY: Antivenom is prepared by hyperimmunisation of

horses with venom of four common snakes COBRA, COMMON KRAIT, RUSSELS’S AND SAW SCALED VIPER.

Check sensitivity by giving a test dose(0.1ml) either I/D or intraconjunctival.

If S/S appear of sensitivity give Epinephrine. Proceed with either of the two ways:

20-50ml antivenin diluted in 5 times normal saline given as an I/V drip @15 drops/min over a period of 45 minutes

1/3rd of total dosage s/c at bite site, 1/3rd I/M, 1/3rd given as I/V.

It is better to give more antivenin then less and in large doses rather than a series of doses

Amount needed inversely propotional to the body size

Adrenaline as needed esp in paralytic casesRespiratory supportBlood transfusion AntibioticsTetanus prophylaxisAnalgesics and sedatives: Codeine and meperidine

ideal. Morphine avoidedHeparin in case of D.I.CSteroids (Hydrocortisone) for allergic

manifestations of antivenomAntiemeticsAntiseizure medicationsAntihistaminesHydration therapy

PREVENTION OF SNAKE BITE Wearing knee high boots.

Torches should be used in snake infested areas while working in fields.

Residential areas surveyed for holes and kept clean. During camping military personnel are to examine

their boots, sleeping bags and beddings. Stay out of tall grass. Be alert while climbing rocks covered with vegitation. Leave snakes alone. Mass public eductaion regarding first aid measures

and health education. Antivenin with appropriate apparatus be provided in

secondary health centres in areas where snake bite is prevalent.

QUIZ1. True about cobra poison*Neurotoxic*Myotoxic*Cardiotoxic*Vasculotoxic

2.Cholinesterase is present in*Elapid*Viper*Sea snakes*All

3.Muscle paralysis is caused by*Sea snakes*Mamba*Krait*python

4. Most characteristic feature of elapidae snake envenomation *Bleeding manifestation*Neuro-paralytic symptoms*Rhabdomyolysis*Cardiotoxicity

References1.http://www.who.int/neglected_diseases/integrated_media_snakebite/en/2. Ilyaas Textbook-Public health and community medicine

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