Snake Poisoning approach

1. SNAKE BITE,
SCORPION, BEE STING

2. INTRODUCTION
• Snakebite is an acute life threatening time limiting medical emergency
• Causes significant mortality
• Treatable

3. Epidemiology
• >2000 species of snakes in the world
• In India about 236 species of snakes (52 are venomous)
• The venomous snakes found in India belong to 3 families
Viperidae (Hemotoxic)
a. Russel’s viper
b. Saw scaled viper
c. Hump-nosed Pit viper
Hydrophidae
(Myotoxic)
a. Sea Snakes
Elapidae (Neurotoxic)
a. Cobra
b. King Cobra
c. Common Krait

4. • 99% of total snake bite in India due to 4 venomous species
• These big 4’s are
1) Indian Cobra ( naja naja)
2) Common Krait (bungarus caruleus)
3) Russell Viper (daboia russeli)
4) Saw Scaled Viper (echis carinatus)

5. • Male were more affected than female .
• 97% snake bites occur in rural area .
• A peak in incidence is found during summer and rainy season.

6. Venom
Modified saliva containing zootoxins from modified salivary
glands
Used by snakes to immobilize and digest prey or to serve as a
defence mechanism against a potential predator
Most of the snakes inject 10% of available venom in a single
strike
(Russel’s viper injects 75%)

7. • Proteolytic enzymes (metalloproteinases, endopeptidases or hydrolases)
-Increase vascular permeability
• Zinc metalloproteinases & haemorrhagins (snake venom metalloproteinases-
SVMPs):
-Degrade basement membrane components
-Leading to endothelial cell damage
• Procoagulant enzymes: (venoms of Viperidae and few Elapidae)
-Cause consumption coagulopathy

8. • Hyaluronidase:
-Increase permeability - promotes the spread of venom through tissues & contribute to
tissue damage
• Venom polypeptide toxins (“neurotoxins”)
 Postsynaptic (α) neurotoxins (α-bungarotoxin and cobrotoxin)
- They bind to acetylcholine receptors at the motor endplate.
 Presynaptic (β) neurotoxins (β-bungarotoxin)
-Damage the nerve endings, prevent further release of acetylcholine
 Acetylcholinesterases: (elapid venoms)
-Cause fasciculation

9.  Phospholipases A2 (lecithinase)
-they damages mitochondria, RBCs, leucocytes, platelets, peripheral
nerve endings , skeletal muscle & vascular endothelium
-Producing presynaptic neurotoxic activity, cardiotoxicity, myotoxicity,
necrosis, hypotension, haemolysis, haemorrhage, plasma leakage

10. 1. Non –Venom Related
2. Venom Related
Dry Bite
• Bites by venomous species are not always accompanied by the injection of venom
(dry bites)
• Symptoms (+) due to anxiety and sympathetic overactivity
CLINICAL PRESENTATION

11. Non Venom Related Symptoms
• Palpitations
• Sweating
• Tremoulessness
• Tachycardia
• Tachypnoea
• Elevated Blood Pressure
• Cold Extremities
• Paraesthesia
• These patients may have dilated pupils suggestive of sympathetic over activity

12. Venom Related Symptoms
Four presenting clinical syndromes of snakebite
1. Progressive weakness (neuroparalytic/neurotoxic)
2. Bleeding (vasculotoxic/haemotoxic)
3. Painful progressive swelling
4. Myotoxic

13. Progressive weakness
(Neuroparalytic Snake bite ; Elapid envenomation)
• 5 D – Diplopia
Dysphonia,
Dysarthria,
Dyspnea,
Dysphagia
• 2 P – Ptosis,
Paralysis

14. Onset of typical symptoms :-
• within 30 min to 6 hours ----- Cobra bite
• 6 – 24 hours ------ Krait bite
(however, ptosis in Krait bite have been recorded as late as 36 hours after
hospitalization)

15. Chronological order of appearance of symptoms –
Furrowing of forehead
• Ptosis (drooping of eyelids)
• Diplopia (double vision),
• Dysarthria (speech difficulty),
• Dysphonia (pitch of voice becomes less)
• Dyspnoea (breathlessness)
• Dysphagia (inability to swallow)

16. 1. Diminished /absent deep tendon reflexes
2. Head lag
Bedside identification of impending respiratory failure
A. Single breath count – number of digits counted in one exhalation - >30 normal
B. Breath holding time – breath held in inspiration –> 45 sec normal
C. Ability to complete a single sentence in one breath.
• Cry in a child whether loud or husky can help in identifying impending respiratory failure.
Signs of impending respiratory
failure

17. Bleeding
(Haemotoxic or Vasculotoxic) – Viperine envenomation
A. LOCAL MANIFESTATIONS
Russel’s viper bite >>> Saw scaled viper .
Least seen -Pit Viper
• Local swelling, bleeding, blistering, and necrosis.
• Pain at bite site and severe swelling leading to compartment
syndrome.
• Tender enlargement of local draining lymph node

18. B.SYSTEMIC MANIFESTATIONS –
• Visible systemic bleeding ( due to haemorrhagins )
• Continuous bleeding from the bite site
• The skin and mucous membranes - petechiae, purpura
ecchymosis, blebs and gangrene.
• Acute abdominal tenderness -gastrointestinal or retro
peritoneal bleeding.
• Localizing neurological symptoms - intracranial bleeding
(eg :-asymmetrical pupils)

19. LIFE THREATENING COMPLICATIONS
 Renal involvement.
• Bilateral renal angle tenderness.
• Passage of discolored urine (reddish or dark brown)
• Acute Kidney Injury (Russell’s viper & Saw scale Viper)
-declining or no urine output,
-deteriorating renal signs such as serum creatinine, urea or potassium.
• Hypotension due to hypovolaemia or direct vasodilatation or direct cardiotoxicity
aggravates acute kidney injury.
 Renal failure, ARDS, Refractory shock.

20. • Rare disorder
• Dreaded complication of russel viper bite
• A/w morbidity and mortality.
• Males >> Females
• Characterized by episodes of
severe hypotension,
hypoalbuminemia,
hemoconcentration without albuminuria
Capillary leak syndrome

21. • Due to profound derangement of the vascular endothelium
resulting in leakage of plasma and proteins into the
interstitial compartment
• Manifestations like parotid swelling, conjunctival chemosis,
myalgia and severe thirst
• Increased Hct
• Leukocytosis
• Pleural effusion
Early
laboratory
&
radiological markers

22. • Long term sequelae
- Pituitary insufficiency ( with Russell’s viper )
- Sheehan’s syndrome or amenorrhea in females

23. Painful Progressive Swelling (PPS)
• Russel’s viper bite >>> Saw scaled viper bite > Cobra bite
• Indicative of local venom toxicity.
• This is associated with
Local necrosis -rancid smell.
Limb is swollen and the skin is taut and shiny.
Blistering with reddish black fluid at and around the bite site.
Skip lesions around main lesion
Ecchymosis

24. • Significant painful swelling potentially involving the whole
limb and extending onto the trunk.
• Compartment syndrome.
• Regional tender enlarged lymphadenopathy

25. Myotoxic
• a /w Sea snake bite.
Patient presents with:
Muscle aches, muscle swelling
Involuntary contractions of muscles
Passage of dark brown urine
 Compartment syndrome
Cardiac arrhythmias due to hyperkalaemia
Acute kidney injury due to myoglobinuria
Subtle neuroparalytic signs.

26. • A/w krait bite
• Krait has nocturnal habitat and has fine slender teeth.
• Bite marks usually cannot be identified even on close
examination.
• Victims often has no history of snakebite & no local signs.
Occult Snakebite

27. • Typical presenting history
Patient was healthy at night,
In the morning - severe epigastric/umbilical pain with vomiting persisting for
3 – 4 hours
Typical neuroparalytic symptoms- ptosis & sudden onset of acute flaccid paralysis- within
next 4- 6 hours.
High degree of suspicion is required for diagnosis Esp in Endemic Areas

28. FIRST AID MEASURES/PRIMARY TREATMENT
“ Do it R.I.G.H.T ”
• Reassurance
• Immobillisation of limb - like a fractured one
• Go to Hospital immidiately
• Tell doctor of symptoms in details and any progression
Vigorous washing incision, suction, application of tourniquet ,cryotherapy, venom stone etc. are absolutely
contraindicated.

29. At A Health Care Facility
• All victims of snakebite (confirmed /suspected ) - Admit & keep
under observation for min 24 hours.
• ABCDE – Airway Protection, Breathing , Circulation,
Disability(level of consciousness),Exposure
• If Tight tourniquet (+) - to be removed carefully .
Apply a BP cuff above the tourniquet and inflate it just above
systolic blood pressure and reduce the pressure gradually
(to prevent rapid of release of poison from bite site which might
lead to sudden worsening of symptoms & Hypotension )

30. ASSESSMENT
• Treating physician should not start treatment or get biased only by
identification of the offending snake.
Primary assessment –
a) Level of consciousness
b) Local site of bite - wound for pain, swelling, necrosis
c) Vitals
d) Bleeding manifestations
e) Neurological signs

31. Inspection of local site of bite
• Examine the bite site and look for fang marks
• Any signs of local envenomation.
• Fang mark or their patterns have no role to determine whether the biting
species was venomous or non venomous or amount of venom injected,
severity of systemic poisoning and nature of poisoning .
• Some species like Krait may leave no bite marks

32. Inspection of local site of bite can also help to identify snake’s species :-
• Local swelling, bleeding, blistering, necrosis ------ Cobra bite.
• Minimum local changes ------ Krait bite.
• Local bleeding ------- Russel’s viper bite.
• Pain in abdomen and hyper peristalsis indicates Krait bite

33. Physical examination
Check for and monitor
• Pulse rate,
• Respiratory rate,
• Blood pressure
• 20 minutes Whole Blood clotting test (20 WBCT)
• Check distal pulses and monitor (if there is increasing edema)
• W/O for development of compartment syndrome.
every hourly for first 3
hours
&
every 4 hourly for
remaining 24 hours.

34. LAB INVESTIGATIONS
• 20 minute whole blood clotting test (20 WBCT): – It is a bedside test
• If clotted, the test should be carried
out every 1 h from admission for
three hours and then 6 hourly for 24
hours.
• In case test is non-clotting, repeat 6
hour after administration of loading
dose of ASV.

35. • Following tests to be done as early as possible -
 Complete hemogram :- hb - hemoconcentration (transient)
hb - hemolysis (viper envenomation)
Neutrophilic leucocytosis- Systemic envenoming
Thrombocytopenia- (viper envenomation)
P/S - fragmented red cells (“helmet cell”, schistocytes) - microangiopathic haemolysis
Liver function test - SGOT, SGPT, ALP
Renal function test- S.Cr - AKI (viper and sea snakebite)
Electrolyte :- patients with respiratory paralysis and systemic symptoms

36. Coagulation profile – BT ,CT ,PT,INR & aPTT prolongation - viper bite
Low fibrinogen & elevated FDP –DIC
Urine examination & microscopy - colour/proteinuria/ rbc/ haemoglobinuria/
myoglobinuria
 Serum creatinine phosphokinase (CPK) - muscle damage
 S .Amylase ------ Pancreatic injury
ECG – 12 leads
(nonspecific ECG changes such as bradycardia and atrioventricular block with ST-T
changes may be seen )

37. Chest X-Ray –Pleural Effusion ,ARDS
Abdominal ultrasound (identification of bleeding)
 Neuroimaging if intracranial hemorrhage is suspected.

38. Specific Ix - Tertiary Health Care Centre
In Vasculotoxic Envenomation
• Cardiotoxicity- CPK-MB, 2D Echo, BNP
• Myotoxicity – CPK, SGOT, Urine myoglobin, Compartment Pressure
• Infection- Serum procalcitonin, culture and sensitivity (blood, urine, wound)
In Neuroparalytic Envenomation
• Arterial blood gases -pH show evidence of respiratory or metabolic acidosis
• Pulmonary function tests assess respiratory function (presenting with neuroparalytic
syndrome)

39. GENERAL MANAGEMENT
• Clean the bitten site with povidone-iodine solution, but do not apply any
dressings
• Administer booster dose of Tetanus toxoid injection
• Antibiotic is not used routinely .
In presence of cellulitis and necrosis ,
Inj. Amoxyclav (1.2gm ) i.v. tds is used for 7 days followed by
tab.amoxyclav(625) - tds for 3-7 days
Inj.metronidazole (400mg ) i.v. tds for 7 days is also used.

40. • Mild pain - Paracetamol 500-1000 mg Q6H P.O (in children 10-15 mg/kg)
• Severe pain - Tab. Tramadol 50 mg or Inj. Tramadol 50 mg IV (in adults)
Do not use aspirin or other NSAIDs.
• Maintain hydration and nutrition.
• Local spreading edema – slightly elevate the affected limb and allow it to rest on a sand bag.
• For hypotension - Normal Saline (30ml/kg ) is used followed by 5% albumin if response is
inadequate.
• If hypotension persists after adequate fluid administration, then start ionotrope
(Inj. Dopamine at 5 – 10 mcg/min)

41. • Watch out for development of Compartment syndrome
 Intra-compartmental pressure >40 mmHg of normal saline (in adults)
 This can be confirmed by vascular Doppler and rising CPK in
thousands
• Clinical features of a compartmental syndrome (5 ‘P’): •
Pain (severe)
Pallor
Paraesthesia
Pulselessness
Paralysis or weakness of compartment muscle.
• Fasciotomy is indicated if compartment syndrome is present

42. Specific Mx
• Antisnake venom (ASV) is the only specific treatment for snake bite
• Should be given as soon as it is indicated.
• 2 types of anti snake venoms
• Monovalent antivenom - neutralises the venom of only one species of snake.
• Polyvalent antivenom - neutralises the venoms of several different species of
snakes
Indian Polyvalent ASV
• Cobra
• Common krait
• Russell’s viper
• Saw - scaled viper
Does not cover
• Pit viper
• King Cobra
• Sea snakes
• Others

43. Administration of ASV
ASV infusion and dosage schedule
• Initial dose is 10 vials
• 10 vials of ASV dissolved in 100 ml of distilled water
and added to 400ml of normal saline
• Infuse at a rate of 10-15 drops/min for first 15min,if
no reaction infuse rest i.v over one hour
• Monitor vitals at 5min interval for 30min & at 15min
interval for 2hrs.

44. REPEAT DOSE IN HEAMATOTOXIC ENVENOMATION
• After initial 10 vials of ASV
Repetition of dose in hemotoxic bite :
 If active bleeding present after 1 hour or
WBCT remain positive after 6 hours
[liver unable to replace clotting factors in under 6 hrs]
• Then give 2nd dose of 10 vials of ASV
• Upto maximum 30 vials.

45. REPEAT DOSE IN NEUROTOXIC ENVENOMATION
►After initial dose 10 vials given
►Repetition of dose in neurotoxic bite :
• If no improvement of symptoms or worsening of condition occurs after 1 hour ,
►Maximum dose of ASV neurotoxic envenomation- 20 vials

46. Management Neurotoxic
(Neuroparalytic) Envenomation
ASV treatment alone cannot save the life of a patient
In addition administer following
i. Oxygen
ii. Administer ‘Atropine Neostigmine (AN)’ schedule
iii. Assisted ventilation - bulbar or respiratory paralysis

47. If signs of neurotoxicity present (eg- Ptosis , Inability to maintain upward gaze)
Administer ‘Atropine-Neostigmine (AN)’ schedule
• Inj. Atropine (0.6mg) followed by Inj. Neostigmine(1.5mg ) i.v. stat
Repeat dose of neostigmine 0.5 mg with atropine (0.6) every 30 minutes for 5
doses
• Thereafter to be given as tapering dose at 1 hour, 2 hour, 6 hours and 12 hour
Dose for pediatric age group :-
Inj.Atropine 0.05 mg/kg and Inj.Neostigmine 0.04 mg/kg and repeat dose 0.01 mg/kg every 30 minutes for 5 doses

48. • Improvement is first noted by improvement of ptosis after 30 min.
50% or more ptosis improves by 1 hour.
• Majority of patients improve within first 5 doses
There is also improvement of
a) single breath count
b) Uncovered area of iris
c) Upper and lower incisor distance
d) Maintenance of upward gaze
e) FEV1 or FVC (if available)
• Improvement by atropine neostigmine (AN) indicates Cobra bite (Postsynaptic
neurotoxin )

49. AN dosage is Stopped if :-
a. Patient has complete recovery from neuroparalysis.
b. No improvement after 3 doses.
c. Patient shows side effects in form of bradycadia or fasciculation
If there is No improvement after 3 doses of atropine neostigmine -Krait
bite
(affects pre-synaptic fibres )
• For krait bite
Inj. Calcium gluconate 10 ml slow i.v. over 10 minutes can be given
every 6 hourly and continue till neuroparalysis recovers .
Neuroparalysis in krait bite takes 5-7 days for complete recovery.

50. RESPONSE TO ASV- RECOVERY PHASE
• General- feels better
(Nausea, headache and generalized aches and pains disappear very quickly)
• Spontaneous systemic bleeding stops within 30 minutes
• Blood coagulability usually restored in 3-9 hrs
(20 minute WBCT becomes negative in 6 hours )
• Neurotoxic Envenomation Signs -
Cobra bite (post synaptic type) may begin to improve 30 min to several hrs,
 Krait bite (pre synaptic type) usually takes hours to days to improve

51.  Patients In shock, BP increase within the first 30-60 min & arrhythmias such as
sinus bradycardia may resolve
 Active haemolysis & rhabdomyolysis -cease in few hrs & urine returns to normal
colour within few hrs - days

52. PERSISTENT COAGULOPATHY
• Prolonged PT/INR - FFP
• FFP administration -more rapid restoration of clotting function
• FFP is given at a dose of 10-15 ml /kg over 30 -60 min within 4 hours of ASV administration
• Normalization of coagulation profile defined as INR < 2.0 after 6 hrs of FFP administration.
• Elevated PT / aPTT , Low fibrinogen and high FDP – Suspect DIC
• Rx- 10-15U of cryoprecipitate for every 2-3U of FFP to correct homeostasis
(or 1-2 bags of cryoprecipitate /10kg BW)

53. PARAMETERS
S .Creatinine > 4 mg/dl or rise by 1 mg/dl/day
Blood urea >130 mg/dl or rise by 30 mg/dl/day
S. Potassium  7 mmol/dl or rise by 1 mmol/dl/day
 Hyperkalemic ECG Changes
Bicarbonate Daily fall >2 mmol/L
Uremic complications encephalopathy, pericarditis
ABG metabolic acidosis
Evidence of Pulmonary edema –Fluid Overload
INDICATION OF HEMODIALYSIS –

54. COMPLICATIONS OF ASV & Mx
• ASV can cause
a) Early anaphylactic reaction
b) Pyogenic reaction
c) Late reaction (serum sickness like)
• Any new sign or symptom after initiation of ASV should be suspected as reaction
• Premedication with inj. Adrenaline (epinephrine) 0.25 mg of 0.1% solution i.e
1mg/ml (1:1000) s/c prevents most reactions

55. EARLY ANAPHYLACTIC REACTIONS
• Within 10–180 min
• Characterized by :- itching, urticaria, dry cough,
nausea and vomiting, abdominal colic, diarrhoea,
tachycardia, and fever
• Minority may develop severe life-threatening
anaphylaxis, hypotension, bronchospasm and
angiooedema

56. If reaction occurs , following measures are taken –
i. Stop ASV infusion temporarly
ii. Moist O2 inhalation
iii. Inj. Adrenaline (1 in 1,000 solution ) – 0.5mg (0.5 ml) I.M. Is life saving.
iv. Inj. Adrenaline is repeated if no response occurs within 15 minutes.
v. 500 ml Normal Saline is infused using a new transfusion set.
vi. Inj. Hydrocortisone - 100 mg & antihistaminic injection like promethazine 25mg or
chlorpheniramine maleate 10mg is given.

57.  Once the patient recovers ,
ASV is started slowly for 10 – 15 minutes keeping the patient under
close observation
If no reaction occurs , then give at normal flow rate .

58. Pyrogenic reactions
• Contamination of the ASV with pyrogens during the manufacturing process
• 1–2 h after treatment.
• Chills and rigors, fever, and hypotension.

59. LATE (SERUM SICKNESS–TYPE) REACTIONS
• 1–12 days (mean 7 day ) after treatment.
• Clinical features include fever, nausea, vomiting, diarrhoea, itching, recurrent
urticaria, arthralgia, myalgia, lymphadenopathy,
• Rarely Glomerulonephritis (immune complex nephritis) and Encephalopathy
Rx
• Inj. Chlorpheniramine maleate 2 mg in adults Q6H for 5 days
• In patients who fail to respond within 24–48 h
A 5-day course of Prednisolone -5 mg Q6H in adults given

60. APPROACH
TO
A
PATIENT
WITH
SNAKE
BITE

61. SCORPION STING
• Arachinoids, that feed on small arthropods and lizard
• Nocturnal
• Tip of the tail- stinger- venom ( neurotoxic)
• Mech- venom is situated near tail tip
• 3 main effects
• neurotoxic- cause Na channels remain to open
• increased excitability of tissue
• Autonomic excitation- SLUDGE( PARASYMPATHETIC)
• SYMPATHETIC – VASOCONSTRICTION-
• LOCAL effect- necrosis is very rare
• Pain- due to serotonin in the venom

62. CLINICAL FEATURES
• LOCAL EFFECTS-
• Pain at the site
• Erythema
• Ascending paraesthesia and hyperesthesia( tap test-worsens on
tapping the affected side)
• Necrosis and swelling – rare

63. NEUROLOGIC
SYMPATHETIC PARASYMPATHETIC
HYPERTHERMIA BRONCHOSPASM
Pr PR, BP, RR HR, BP
DIAPHORESIS SLUDGE
ARRYTHMIA MIOSIS
PULMONARY EDEMA DYSPHAGIA
PILO ERECTION PRIAPISM
SEIZURES LOSS OF BOWEL AND BLADDER CONTROL
RESTLESSNESS GENERALISED WEAKNESS
COLD ECTREMITIES SWEATING- SKIN DIARRHEA

64. • CRANIAL NERVE PALSIES
• Blurring of vision, ptosis, dysphagia, dysarthria,mydriasis
• GIT-nausea, vomiting, toxic hepatitis, acute pancreatitis
• last phase- catecholamines get depleted ---- hypotension,
bradycardia

65. MANAGEMENT
• LOCAL TREATMENT
• Ice application
• Topical anaesthetic
• TT
• Local wound care
• Muscle spasm

66. • Systemic
• ABC
• Oxygen
• Iv fluids,oral fluids
• Pain- BZD, NSAIDS
• AUTONOMIC DYSFUNCTION- ALPHA BLOCKER, alpha+ Beta blocker

67. Bee sting
• Bee injects venom into the skin through its stinger
• CLINICAL FEATURES- local-
• Pain, redness and swelling,itching
• signs of anaphylaxis- dyspnea, dysphagia, palpitations, wide spread
rashes beyond sting site, dizziness confusion
• Treatement- remove the stinger immediately if visioble
• wash the area with soap and water
• Ice pack – to reduce pain and swelling
• Pain- paracetamol
• Antihistamines for itching
• anaphylaxis- steroid and adrenaline