Management of snake bite National Guideline 2014

Dr. Forhad Uddin Hasan Chowdhury (Maruf)Assistant Registrar (Medicine )Dhaka Medical College Hospital

INTRODUCTION

Snake bite is an important public health hazard in Bangladesh

Estimated an annual incidence of 623/100,000

6,041 deaths annually.

Neurotoxic snakes like (Cobra, Kraits) are causing significant mortality and morbidity

Among the vipers green pit viper is very common but there are few cases of Russell's viper.

Rahman R,Faiz MA,Selim S,Rahman B, Bashar A,et el.Annual incidence of snake bite in rural Bangladesh.PLoS Negl Trop Dis.2010 Oct;4(10):e860.

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Moonocled Cobra(Naja Kaouthia)

Binocellate CobraNaja naja

King cobra (Opiophagus hannah)Copy right- Dr.T N S Murthy

Branded Krait(Bungarus fsciatus)

Common Krait(Bungarus Caeruleus)

Bungarus walli Bungarus nijer

Common vipers in Bangladesh

Spot tailed pit viper

White lip pit viper

Pope’s pit viper Russel’s viper

Russell’s viper

Sea snake (Hydrophidae sppCopy right- Prof. D A Warrell

What is venomous snake bite?

► A bite by venomous snake which produces specific symptoms or a syndrome is considered as venomous snake bite.

► A venomous snake may not and do not always features of envenoming

► 50% of bites by Russell’s viper , 30 % of bite by Cobras and 5-10% of bites by saw scaled viper do not result in any symptoms or signs of envenoming

► A victim may develop some features due to anxiety or apprehension in case of bite by a venomous as well as NV snake.

History taking

Site of bite, circumstances of bite, time of bite how did it happen?

Site Face and limbs- Green pit Limbs- Cobra Any site- Krait Forearm- See snakeTime: Night time bite especially in Krait bite

Non specific symptoms: Headache, Nausea, vomiting, abdominal pain, loss of consciousness, difficulty in vision, convulsions

Neurological symptoms: Muscle paralysis, difficulty in moving jaw,toungue,eye, heaviness of eye lids (ptosis), weakness of neck muscles (broken neck sign), difficulty in swallowing, dribbling of saliva, nasal regurgitation, nasal voice, difficulty in respiration, extreme generalized weakness

Haematological symptoms: Spontaneous bleeding from gum,vomiting of blood, Coughing out of blood, passage of blood per urethra, persistent bleeding from bite site, venepuncture site and inflicted wound if any.

Others: Severe muscle pain, dark urine, scanty urination, collapse.

Concomitant medical illness: H/O allergy, Bronchial asthma, kidney, heart disease, bleeding disorders, neurological disease, limb swelling etc.

In female: Whether the victim is pregnant or not, whether the victim menstruating or not.

H/O pre hospital treatment:

1. Home treatment. 2.Treatment from traditional healers (Ozha or Baiddya). 3.Application of tourniquet. 4.H/0 immunization against tetanus. 5.Treatment by initial attending physician.

Physical examination

1.Rapid clinical assessment especially vitals: Pulse, BP, Respiration, Temp

2.Systemic signs of envenoming: Chronology of onset and progression of signs.

a. Neurotoxic sign:• Ptosis(Partial or complete) usually symmetrical and

progressive• Diplopia, external ophthalmoplegia• Bulbar palsy• Nasal voice• Facial paralysis• Inability to open the mouth and to protrude the toungue• Paralysis of chest muscle and diaphragm (Shallow

breathing)• Broken neck sign: Weak grip, diminished reflexes

b.Signs of haematological abnormality:• Persistent bleeding from bite site, venepuncture site and

or inflicted wound if any• Multiple bruise or large blood collection• Haemorrhagic blisters• Bleeding from gingival sulci• Haemoptysis• Haematuria• Epistaxis

Presentation of pit viper bites

1.Local swelling2.Spontaneous bleeding from bite site

3.Haemorrhagic blister4.Myotoxicity5.Renal failure6.Intracranial haemorrhage

c.Signs of Renal failure: Scanty or no micturation,dark urine Clinical uraemic syndrome: Nausea, vomiting, hiccups,

fetor, drowsiness,coma, flapping tremor, muscle twitching, convulsion, pericardial friction rub, signs of fluid over load

d.Signs of myotoxicity: Muscle tenderness, weakness, respiratory failure,

black urine, renal failure

c.Signs of local envenoming: Swelling, tenderness, bleeding, ulceration,necrosis,

local lymphnode enlargement

GREEN PITCOBRA COBRA

KRAITCOBRA NON VENOMOUS

Identification of snake

• Identification of snake by description or by model,photograph, brought snake, preserved specimen.

By local examination- • Classic fang and teeth mark rarely occur and if present

indicate venomous snake bite• Scratch usually indicates nonvenomous snake bite but

may rarely found in krait bite• Snake may bite through clothing

Syndromic approach

Syndrome-1

LOCAL ENVENOMING (SWELLING OF LIMBS)

+ BLEEDING OR CLOTTING DISTURBANCE

Green pit

Rassell’s viper

LOCAL ENVENOMING (SWELLIMG) + BLEEDING OR CLOTTING

DISTURBANCE (WBCT >20MINS + SHOCK OR AKI + NEUROTOXIC SIGN + DARK BROWN URINE

Syndrome -2

Rassell’s viper

Syndrome -3LOCAL ENVENOMING(SWELLING)+NEUROTOXIC FEATURE+NO CLOTTING DISTURBANCE(WBCT <20 MINS)

COBRA

Syndrome -4

NO LOCAL ENVENOMING+NEUROTOXIC FEATURES+WBCT <20 MINS

Bite in land while sleeping = KRAIT

Bite in the sea= SEA SNAKE

Syndrome -5

PARALYSIS+DARK BROWN URINE+NO LOCAL SWELLING+WBCT <20 MINS+SEVERE MUSCLE PAIN

Bite in the sea=SEA SNAKE

Bite in the land= KRAIT

KEEP IT IN MIND: Identification of snake the offending snake from fang mark is impossible.

Local swelling and tissue damage:• First sign of envenoming• Exceptions kraits sometimes in cobras• Blister necrosis

Other systemic examinations:

Laboratory investigations

• Coagulation test- 20 min whole blood clotting test• ECG• CBC• Blood urea, S.Creatinine• Urine R/E and naked eye examination of urine• APTT ,PT• S.CPK• ELISA• Blood grouping and Rh typing

20 min whole blood clotting test. (20 WBCT)

• Place a few mls of freshly sampled venous blood in a small glass tube

• Leave undisturbed for 20 minutes at ambient temperature, erect.

• Tip the tube once

• If the blood is still liquid (unclotted) and runs out, the patient has hypofibrinogenaemia “incoagulable blood” as a result of venom induced consumption coagulopathy.

• In perspective of Bangladesh, incoagulable blood is diagnostic of a viper bite and rules out an elapid bite.

The management of snake bites

Recommended first aid

1. Reassurance

2. Immobilization

3. Lower limb- DO NOT WALK

4. Upper limb- DO NOT MOVE the limb

5. Should not be used for Viper Bites.

QUICK TRANSFER

1.COMMUNITY CLINIC

2.UHC

3.DISTRICT HOSPITAL

4.MEDICAL COLLEGE HOSPITAL

Pressure immobilization method

PLEASE KEEP IT IN MIND

• DO NOT WASTE TIME TO ANY OZHA OR TRADITIONAL HEALERS

1.NOT scientific2.Waste of time3.May cause infection, bleeding, gangrene4.Damage to artery , vein5.Loss of life6.Always Harmful

HARMFUL- NOT RECOMMENDED

1.Tight tourniquets2.Incision at the bite site3.Local suction4.Cauterization by chemicals5.Application of materials6.Ingestion of herbal products to induce vomiting7.Unnecessary delaying

Treatment in hospital

1.Rapid clinical assessment and resuscitation (ABC)

2.Detailed clinical assessment (Local, Neurological, Haematological)

3.Identification of species (Brought snake live, dead or description, photograph 20 min WBCT Syndromic approach)

N.B-. DO NOT ATTEMPT TO KILL THE SNAKE , AS THIS MAY BE DANGEROUS. DO NOT

HANDLE THE SNAKE WITH BARE HANDS, AS EVEN A SEVERED HEAD CAN BITE!

Treatment: a.Antibiotic b.Tetanus prophylaxis c.Antivenom d.NBM

Polyvalent Antivenom: In our country now only Polyvalent antivenom from Vins

(lindia) is available in lyophilized powder form. Each vial contain 10 mg of antivenom, which is effective against systemic envenoming by Cobra, Krait, Russell's Viper and Saw scaled viper only (there is no evidence of Saw scaled viper in Bangladesh). So this type of antivenom should not be used in bites by Green snake, Sea snakes and identified non-venomous snake.

Antivenom treatment

Indication /criteria for using antivenom:

(Not indicated in Green snake and sea snake)1.Neurotoxic signs.2.Rapid extension of swelling (more than half of the bitten

limb). N.B- not due to green snake bite or tight tourniquet.

3.AKI (not due to see snake).4.Crdiovascular abnormalities5.Bleeding abnormalities.6.Haemoglobinuria/myoglobinuria not due to sea snake.

Anti snake venom therapy

• Dose: Each dose consists of 10 vial of polyvalent antivenom

irrespective of age and sex of the victim.

• Time and administration: Each vial is diluted with 10-ml. of distilled water. 10 such vials

(100 ml) is further diluled or mixed with 100 ml of fluid (Dextrose water or saline). Then it is administered with intravenous infusion within 40-60 min (60-70 drops/min).

• Observation and monitoring: Continuous observation and frequent monitoring of vital signs

should be ensured during antivenom therapy and few hours after its completion. Careful clinical assessment for appearance of signs and symptoms of antivenom (A/V) reaction should be performed.

Polyvalent anti-snake venom

Active against1.Indian cobra2.Common Krait3.Russsel’s viper4.Saw scaled viper

Antivenom reaction:Three types of reaction occurs

1.Early anaphylaxis

2.Pyrogenic reaction

3.Late reaction (serum sickness type)

1.Early anaphylaxis:• Usually develops within 10-180 min of starting of

antivenom• C/F- Itching,urticaria,fever,angiooedema,dspnoea,

bronchospasm,laryngeal oedema, hypotension, abdomina pain, vomiting, diarrhoea etc

Treatment of anaphylaxis

• Temporary suspension of antivenom administration• Inj.Adrenalin (I/M) (1 amp=1ml=1mg) For adults: 0.5ml (1/2 amp) For children: 6-11 years 0.25 ml (1/4TH amp)

• Antihistamin (Inj.Chlorpheniramin) Adult= 10 mg IV slowly after dilution Child=0.2 mg/kg slow after dilution

• Inj.Hydrocortisone 100 mg for adults (2mg/kg for children.)

• Inj.Ranitidine 50 mg IV slowly 1mg/kg for children.

(N.B- Should be given at the very 1st sign of reaction and can be repeated every 5-10 mins intervalif condition is deteriorating)

2.Pyrogenic reaction:• Usually develops 1-2 hours after treatment• C/F- chills, fever, fall of BP, febrile convulsion in children• Treatment- Tepid sponging,fanning,IV fluid, Paracetamol

suppository.

3.Late reaction (Serum sickness type):• May develop 1-12 days (mean 7 days) after treatment.• C/F-Fever ,itching,urticaria, arthralgia,myalgia,

lymphedenopathy, proteinuria etc.• Treatment- Antihistamin, prednisolone (if no response to

antihistamin)N.B- If any concomitant medical illness like COPD,

Bronchial asthma or pregnancy ½ of the dose of adrenalin (1/4th amp) should be given S/C before giving antivenom

Additional treatment:Inj.Atropine (15µg/kg ) IV (1.5 amp for adult) 4 hourly &Inj.Neostigmine (50-100 µgm/kg) S/C (2.5 amp for adult) in

each thigh 4 hourly until neurotoxic features improve

Respiratory support- Incase of respiratory failure

Blood transfusion: For patients with coagulopathy.

Endotracheal intubation is the most essential part of the management of venomous snakebite with respiratory failure

DAY 1 DAY 1 DAY 2

DAY 3 DAY 4

AFTER ADMISSION BITE SITE

AFTER ASV TREATMENTT

RECOVERY

Criteria for repeating the initial dose of antivenom:Persisting or deteriorating signs of systemic antivenom.eg.

1.If no improvement or deterioration of neurotoxic features (cobra or krait) 1-2 hours completion of antivenom.

2.Persistence or recurrence of blood incoagulopathy after 6 hours of antivenom teatment.

Drugs not recommended:1. Antihistamine except for antivenom reaction2. Corticosteroid except antivenom reaction3. Sedative4. Antifibrinolytic agent5. Heparin6. Traditional medicines (from ozahs)

Treatment of bitten part:

• Elevation of limb with rest• Simple washing with antiseptic solution• Broad spectrum antibiotic (especially when there is

features of contamination, multiple incisions)• In case of local necrosis and gangrene: Broad spectrum antibiotic Surgical debridement and split thickness skin

grafting is indicated.

Follow up: Local envenomation: The snake bite cases with Local envenomation (commonly in cobra cases) need to follow up for at least 5- 7 days to see the sequential changes of color changes, blisters, ulceration, necrosis and desquamation. In viper bites, the haemorrhagic manifestation should also follow up to see complete recovery. A comprehensive approach with advice from surgeons are important in this regard

Children : The neurotoxic snake bite cases should be followed up to observe any neurological residual deficit present or not with also attention to neurocognitive function.

Pregnancy: The pregnancy outcome after a venomous bite with long term follow up of children is also needed to see the neurological cognitive function

Rehabilitation:

Physiotherapy Reconstructive surgery

What should we do when no antivenom is available?

Incase of neurotoxity:• Assisted ventilation via ambu bag or mechanical

ventilation• Inj.Atropine and Neostigmine:

In case of Haematological abnormality:• Strict bed rest to avoid even minor trauma• I/M injection must be avoided• Fresh whole blood or FFP transfusion should be given

List of Essential Logistics for snake bite Management:

• One 10 cc syringe• One 20 cc syringe • Two 50 cc syringe• IV infusion set- two sets• IV blood transfusion set – One set• IV canula (JMS): two sets• IV Normal Saline -500 ml• Indwelling catheter• Urinary bag

• Antivenom -10 vials with diluents• Inj Atropine – 6- 10 amp: 15 mcg/kg• Inj Neostigmine (500 mcg)- 20-25 amp (For adults)- 50mcg/kg• Inj antibiotics• Tetanous Toxoid- 1amp• Inj Adrenaline (1:1000)- 2-3 amp• Inj Chlorphenarmine- 1-2 amp• Paracetamol Suppository- 1-2 stick• Inj Hydrocortisone- 4-5 vials• Inj Ranitidine- 4-5 ampoules • Water and soap

• Antiseptic lotions or cream• Gauze and coton (For wound care and sling)• Insulin syringe (For collection of wound swab)• Sterile vials (for collection of swab, blood etc)• 10 cc dry test tube with holding stand (For 20 min WBCT)• Sterile test tube (For blood sample)• Endotracheal tube- 2 set (One for pt and one reserve)• 5 cc syringe-2 ( for balloon inflation of ET tube and catheter)• Umboo bag- one at least dedicated for snake bite• Orogastric tube• Laryngoscope • Battery for laryngoscope• Trolly with tray- dedicated for snake bite logistics

ANY QUESTION?

THANK YOUThank you