Case based discussion -Snake Envenomation

Dr. Zaheen Zehra Dept of Paediatrics.

• 7 yr old boy brought with alleged h/o unknown bite on 11/03/17 at 10:30 am at home.

• Site of bite- dorsum of left foot• C/o Excrutiating pain and swelling on the left leg.• After 1 hr child sustained localised swelling,H/o

progression of swelling upwards till left knee associated with pain.

• No h/o bleeding from the site, LOC, Seizures, Ptosis• No respiratory distress

• Past History: No significant past history

• Family History: Nil significant

• Antenatal and perinatal history: Nil significant

• Immunisation History: Upto date

• Growth and development: Normal

Treatment History:• Child was immediately taken to Kallukurichi GH,

diagnosed as snake bite with cellulitis of left leg.

• Treated with IV fluids, Inj.Tramadol, Inj.Rantac, Inj.Taxim, Inj.Metrogyl, ASV.

• Dose of ASV not mentioned. Not given premedications

• Referred that day for ASV allergy.

ON EXAMINATIONInitial assessment: StablePrimary assessment : Normal - (Urgent)Active,febrileGCS-15/15Vitals:Temperature-100 FPR-130/minRR-24/minCFT-<3 secBP-130/90mmHgBreath holding time – adequateNo bleeding sites

SYSTEMIC EXAMINATION:• Respiratory System:B/L AE equal, NVBS Heard.• CNS:Sensorium-normal;No ptosis• CVS:S1,S2 heard; Tachycardia present• P/A:Soft, non tender, no organomegaly, no renal angle

tenderness

LOCAL EXAMINATION:• Warmth,swelling and tenderness till distal one

third of the lower limb(Below knee)• Fang mark on the dorsum of the left foot• Blebs and discolouration present• Peripheral pulses felt, no evidence of

compartment syndrome• Left inguinal lymphadenopathy present- Tender+

• Provisional diagnosis of Left leg cellulitis- secondary to ?snake bite envenomation was made and child was shifted to PICU

• Whole blood clotting time done- less than 20mins• CBC showed TLC 12,000 with plt of 2.18lakhs• RFT was normal• Child empirically started on iv ceftriaxone and

metronidazole• Monitored for urine output, increase in

swelling,compartment syndrome.

• On day 3 of hospitalization - pus c/s was sent from the bleb.

• Pediatric surgery opinion taken on day 3 of hospitalization- Opined as Necrotizing fascitis of leg.(Evolving)

• Iv antibiotics was changed to ampiclox and amikacin and metronidazole was continued.

• Wound debridement with fasciotomy was done on day 5 of hospitalisation. Tissue culture was sent.

• Pus c/s (aerobic & tissue culture showed

evidence of klebsiella pneumoniae sensitive to

the ciprofloxacin, ceftriaxone, amikacin,

magnex, meropenem

• Anaerobic culture : sterile

• Taken over by paediatric surgery. Daily wound dressing done.

• Planned to do skin grafting after 2 weeks.

Snake Envenomation

• Highest Mortality in the world.• Deaths of 30,000 per annum. (WHO 2009)• 236 species of snakes in India• 15 varieties are poisonous.• Cobra, Russell's viper, saw- scaled,vipers and

krait are the most common.

Cobra

Naga Pambu or Nalla pambu

நாகப் பாம்பு/ நல்லபாம்பு

Naja naja

Common Krait

Bungarus caeruleus

Kattu viriyan/ Thani Paambu

கட்டு விரியன்

Saw scaled snake

Echis carinatus.

Surutai pambu

Russell’s Viper

Daboia russelii

கண்ணாடிவிரியன்

Kannaadi Viriyan

Common Name ofthe snake

Nature of Toxin

Local symptoms and signs at bite

Systemic Signs and Symptoms

Russell's Viper HaemotoxicNeurotoxic

1.Pain at bite site2.Ecchymoses and3.swelling4.Blister formation 5.Necrosis of the limb

1.Rise in CT/BT2. Bleeding from various sites.3. AKI

Saw Scaled Viper Haemotoxic 1.Local pain 2.Ecchymoses 3.swelling4.Bleeding from the site5.Rapid discolouration

1.Rise in CT/BT.2.Bleeding from various sites.

Common Name ofthe snake

Nature of Toxin

Local symptoms and signs at bite

Systemic Signs and Symptoms

Cobra Neurotoxic (post synaptic)

1.Local pain.2.Swelling.3.Ecchymoses4.Local necrosis

1.Sluggish pupillaryResponse.2.Diplopia, Ptosis, Dilated pupils,arrhythmia. 3.Difficulty in breathing,Hypotension.4.Unconscious state.

Common Name ofthe snake

Nature of Toxin

Local symptoms and signs at bite

Systemic Signs and Symptoms

Common Krait Neurotoxic(pre-synaptic)

1.Small puncture marks.2.Minimal or absentIocal symptoms3.GI Manifestations.

1.Sluggish pupillaryresponse, ptosis,Diplopia, Dilated Pupils.2.Difficulty inswallowing due toGlossopharyngeal dysfunction. 3. Difficulty inRespiration.4. Arrhythmia,hypotension, Ioss ofconciousness, coma,respiratory arrest, andsudden cardiac arrest.

“Do it R.I.G.H.T”

• R: Reassure the patient.• I: Immobilise in the same way as a fractured

limb.• G.H: Get to Hospital Immediately.• T: Tell the doctor of any systemic symptoms

such as ptosis that manifest on the way to hospital.

Methods to be Discarded• Tourniquets• Cutting and Suction• Washing the Wound• Pressure Immobilisation Method (PIM)• Freeze or apply extreme cold to the area of

the bite.• Attempt to suck venom out with mouth

Approach

• Initial Assessment and history.• Symptoms:Feature Cobras Kraits Russell's

ViperSaw ScaIed Viper

Local Pain/ Tissue Damage yes No Yes Yes

Ptosis/ Neurological Signs Yes Yes Yes No

Haemostatic abnormalities

No No Yes Yes

Renal Complications No No Yes No

Response to Neostigmine Yes No No No

Response to ASV Yes Yes Yes Yes

• Hump nose viper• Common in kerala• Hemotoxic and nephrotoxic• AVAILABLE ASV IS NOT EFFECTIVE

Investigations• 20 minutes whole blood clotting test• Haemoglobin/ Pcv/ Platelet count/ PT/ APTT/

FDP/ D-Dimer• A Peripheral Smear• Urine for for Proteinuria/ RBC/

haemoglobinuria/ myoglobinuria• Sr.creatinine/urea/Potassium

TREATMENT

• Managing pain:

This can be treated with painkillers such as

Paracetamol.

• Handling Tourniquets:

Before removal of the touniquet, check for the

presence of pulse distal to the tourniquet.

Anti Snake Venom (ASV) • INDICATION:Evidence of systemic envenomationEvidence of coagulopathy: Primarily detected by

2OWBCT or visible spontaneous systemic bleeding etc.

Evidence of neurotoxicity: Ptosis, external ophthalmoplegia, muscle paralysis,inability to lift the head etc

Severe Local envenomation

• Premedication : Hydrocortisone 2-5 mg/Kg Chlorpheniramine 0.1-0.3 mg/kg Ranitidine 2 mg /kg Dosage: 10 vials Russell's viper injects 63mg (Range 5mg - 147

mg; SD 7 mg) of venom- each vial contains 6mg of ASV

• Route of administration- Intravenous infusion 10 vials of ASV is diluted in 10-20ml/kg of

isotonic saline and given over one hour• Child is monitored closely for ASV related

reactions.Locally instilling ASV on bite site to be avoided

ASV ReactionsIn cases of anaphyllaxis• Discontinue ASV infusion• 0.01mg/kg adrenaline 1 :1000 given IM• Second or third dose may be repeated if

symptoms not reversed• If anaphyllactic shock – start adrenaline

infusion• Once recovered, ASV can be restarted slowly

Recovery Signs• Spontaneous systemic bleeding such as gum bleeding

usually stops within 15 – 30 minutes.• Blood coagulability is usually restored in 6 hours.

Principal test is 2OWBCT.• Post synaptic neurotoxic envenoming such as in Cobra

bites, may begin to improve as early as 30 minutes after antivenom, but can take several hours.

• Active haemolysis and rhabdomyolysis may cease within a few hours and the urine returns to its normal colour.

• In patients with Shock, blood pressure may increase after 30 minutes

When and how much repeat dose

• Hemotoxic snake bite: Maximum 25 vials After 6 hours• Neurotoxic snake bite: Maximum 20 vials After 1-2 hours

• Why ASV not effective after delayed presentation or persistent local swelling?

ASV acts in the circulation to prevent binding of unbound venom

Complications• Hypotension• Persistent or severe bleeding• Renal Failure: • Cardiac Complications

Surgical Complications

• Ulcer following snakebite• Necrosis of the skin and underlying tissues• Gangrene of the toes and fingers• Debridement of necrotic tissues• Compartment syndrome.

Role of Antibiotics• Most common organism causing local reactions or infection - Staph. Aureus- E. Coli- Different choices being mentioned Combination of ampiclox and cefotaxime Ciprofloxacin Metronidazole to cover anaerobesReference:1.Dhanya Sasidharan Palappallil et al., Antibiotic Usage After Snake Bite Journal of Clinical and Diagnostic Research. 2015 Aug, Vol-9(8)Kerala Based Study.2. Wound infections secondary to snakebite Atul Garg, S. Sujatha, Jaya Garg, N. Srinivas Acharya, Subhash Chandra Parija Department of Microbiology, Jawaharlal Institute of Postgraduate Medical

Education and Research (JIPMER), Pondicherry

How do we decide on Antibiotics??

• Invariably skin gets necrosed after initial few days of snake bite due to proteolytic properties of venom.

• If no features of septicemia or if local skin appears relatively healthy amoxyclav or ceftriaxone or ciprofloxacin is enough.

• If skin shows necrotising features or child is very toxic then Cloxacillin (or piptaz )+ amikacin + metronidazole can be added.

• THANK YOU