snake bite lecture
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SNAKE SNAKE BITEBITE
Presented By:Presented By:AMO WEBBER SIGOAMO WEBBER SIGO
INTRODUCTIONINTRODUCTIONVenomous snake are predators. As man is not Venomous snake are predators. As man is not the usual prey, most venomous bites in human the usual prey, most venomous bites in human are are “defensive” bites“defensive” bites with small amount of with small amount of venom “injected”. This explains the relatively venom “injected”. This explains the relatively low mortality due to snake biteslow mortality due to snake bites..
In In bites by land snakesbites by land snakes, the greater the , the greater the local local tissue damagetissue damage, the larger the amount of venom , the larger the amount of venom introduced an vice versa.introduced an vice versa.
In In bites by sea snakesbites by sea snakes, local tissue injury tends , local tissue injury tends to be negligible and is to be negligible and is often missed or ignoredoften missed or ignored; ; the systemic and neurological impact of the the systemic and neurological impact of the venom on the other hand could be devastating.venom on the other hand could be devastating.
A.A. Classes and Features of Poisonous Classes and Features of Poisonous Snakes in MalaysiaSnakes in Malaysia
1.1. ElapidaeElapidaeCobra: Large snake, 6’-18’ long (adult), brown blackCobra: Large snake, 6’-18’ long (adult), brown black in colour, erect fore body with spectacular in colour, erect fore body with spectacular outspread hood, hissing, no Loreal pit, third outspread hood, hissing, no Loreal pit, third upper labial scale enlarged.upper labial scale enlarged.
Coral Snakes: small & Slender snakes, brightly Coral Snakes: small & Slender snakes, brightly coloured, no Loreal pit, third upper coloured, no Loreal pit, third upper labial scale enlargedlabial scale enlarged
Kraits: Body is triangular in cross section, vertebralKraits: Body is triangular in cross section, vertebral scale enlarged, no Loreal Pit, third upper labialscale enlarged, no Loreal Pit, third upper labial scale not enlarged.scale not enlarged.
1. Elapidae1. Elapidae
CobraCobra KraitsKraitsCoral SnakeCoral Snake
2. Viperidae2. ViperidaeVipers: Loreal pit present on head betweenVipers: Loreal pit present on head between eye and nostril, head triangular in eye and nostril, head triangular in shape, distinct neck.shape, distinct neck.
2. Viperidae2. Viperidae
pope-viper
temple-viper
malayan-viper
3. Hydrophidae3. HydrophidaeSea snake: Tail laterally flattened.Sea snake: Tail laterally flattened.
3. Hydrophidae3. Hydrophidae
B. Clinical FeaturesB. Clinical FeaturesGeneral Examination.General Examination.1.1. Check Vital signs,Check Vital signs,2.2. A, B, CA, B, C3.3. Assess angionedema & shockAssess angionedema & shock4.4. Confusion or drowsiness, L.O.CConfusion or drowsiness, L.O.CWound Inspection.Wound Inspection.1.1. Look for local tissue destruction: Oedema,Look for local tissue destruction: Oedema,2.2. blisters, Erythema or discolouration of blisters, Erythema or discolouration of
affectedaffected3.3. limb and trunk.limb and trunk.
B. Clinical FeaturesB. Clinical FeaturesSystemic effects.Systemic effects.Paraesthesia-signal release of neurotoxinParaesthesia-signal release of neurotoxin (Coral Snakes)(Coral Snakes)Symptoms:-Hypotension, Bleeding (Epistaxis,Symptoms:-Hypotension, Bleeding (Epistaxis, petechial haemorrhages &petechial haemorrhages & lymphadenopathy.lymphadenopathy.
Other serious effect that can occur are:-Other serious effect that can occur are:-Coma, seizures, pulmonary oedema, ARDS,Coma, seizures, pulmonary oedema, ARDS,Acute Pancreatitis & ARFAcute Pancreatitis & ARF
B. Clinical FeaturesB. Clinical Features
Local Effects:Local Effects:
Type of Type of snakesnake
Pain Pain at bite at bite sitesite
Local Local OdemaOdema
Pain in Pain in regional regional Lymph Lymph nodesnodes
Local Local NecrosisNecrosis
Local Local skin skin discolodiscolourationuration
CobraCobra ++++++ ++++++ ++++++ ++++++ ++++++
Coral Coral SnakeSnake
++++++ ++++ ++ -- ++
KraitsKraits ++ -- ++ -- --
1. Elapids 1. Elapids (Neurotoxic)(Neurotoxic)
Vomiting:Vomiting: Early sign of systemic Early sign of systemic envenoming.envenoming.
Neurotoxicity:Neurotoxicity: Most important effect of Most important effect of elapid venoms. May appear as soon as elapid venoms. May appear as soon as 15-20 min or delay for many hours.15-20 min or delay for many hours.
Symtoms:Symtoms: Blurred Vision, Circumoral Blurred Vision, Circumoral and gum paraesthesia, hypersalivation and gum paraesthesia, hypersalivation and drowsiness.and drowsiness.
Signs:Signs: Ptosis, Paralysis of upward Gaze, Ptosis, Paralysis of upward Gaze, inability to open mouth, protrude inability to open mouth, protrude tongue, speak and swallow, tongue, speak and swallow, respiratory paralysis, generalized respiratory paralysis, generalized flaccid paralysis flaccid paralysis
2. Vipers (Haemotoxic)2. Vipers (Haemotoxic)
Local Effects:Local Effects: Pain, local swelling and bruising within 1-Pain, local swelling and bruising within 1-2 hr, may spread to involve the whole 2 hr, may spread to involve the whole limb and adjacent trunk over the next 2-3 limb and adjacent trunk over the next 2-3 days and may cause necrosis. Tender days and may cause necrosis. Tender lymph node is common.lymph node is common.
Haemostatic abnormalities:Haemostatic abnormalities: Spontaneous Spontaneous systemic bleeding e.g at gingival sulci, nose, GI systemic bleeding e.g at gingival sulci, nose, GI tract, Skin and Intracranially.tract, Skin and Intracranially.
Shock:Shock: Hypovolemia, result from leakage of Hypovolemia, result from leakage of blood and plasma into the bitten limb or increase blood and plasma into the bitten limb or increase in capillary permeability resulting in pulmonary in capillary permeability resulting in pulmonary oedema dan effusions.oedema dan effusions.
Cardiac arrhythmiasCardiac arrhythmias and EEG abnormalities and EEG abnormalitiesAcute Renal FailureAcute Renal Failure may occur. may occur.
1. Sea snakes (Myotoxic & Neurotoxic)1. Sea snakes (Myotoxic & Neurotoxic)
All sea snakes in Malaysia are All sea snakes in Malaysia are poisonous or Venomouspoisonous or Venomous
Local Effects: Local Effects: Little Pain, no oedema at the site of bite. Little Pain, no oedema at the site of bite. Fish sting are painful.Fish sting are painful.
Myopathic/myotoxic effect:Myopathic/myotoxic effect: Generalized muscle pain, weakness and Generalized muscle pain, weakness and myoglobinuria. Tendon reflexes may be myoglobinuria. Tendon reflexes may be depressed and Respiratory failure may depressed and Respiratory failure may occur.occur.
Neurotoxic:Neurotoxic: Ptosis, Trismus, BOV. Ptosis, Trismus, BOV.
ARF and Cardiac arrest ARF and Cardiac arrest due to due to Hyperkalamia. Hyperkalamia.
C. Treatment of Poisonous C. Treatment of Poisonous Snake BitesSnake Bites
Admit all snake bites for observation. If Admit all snake bites for observation. If severe, seek ICU Medical Team severe, seek ICU Medical Team consultation.consultation.
In all cases of suspected venomous In all cases of suspected venomous snake bite, it is imperative to “diagnosis” snake bite, it is imperative to “diagnosis” the class of snake involved, in order to the class of snake involved, in order to predict the type of damages and to decide predict the type of damages and to decide on the type of anti-venom.on the type of anti-venom.
C. Treatment of Poisonous C. Treatment of Poisonous Snake BitesSnake Bites
The following points could help:The following points could help:a)a) Make the patient describe the snake Make the patient describe the snake
(show pictures or photographs if (show pictures or photographs if available).available).
b)b) Establish the geographic location of the Establish the geographic location of the bite to differentiate between sea snake bite to differentiate between sea snake and land snake bites ( Riverine areas and land snake bites ( Riverine areas close to the sea might have sea snakes if close to the sea might have sea snakes if the river water is salty ).the river water is salty ).
C. Treatment of Poisonous Snake C. Treatment of Poisonous Snake BitesBites
1.1. First AidFirst Aid ReassuranceReassurance Immobilization of the bitten limb with a Immobilization of the bitten limb with a
splint or sling.splint or sling. Identify the snake if the snake has Identify the snake if the snake has
been killed: this is very important if the been killed: this is very important if the right anti-venom is to be given.right anti-venom is to be given.
Inspect the bite: The bite of venomous Inspect the bite: The bite of venomous land snake usually produce two clean land snake usually produce two clean puncture wounds (fang marks) with puncture wounds (fang marks) with swelling and discolouration if significant swelling and discolouration if significant venom has been injected. Non-venom has been injected. Non-venomous land snake bite produces venomous land snake bite produces very negligible local effect.very negligible local effect.
Do not cut or squeeze the bite woundDo not cut or squeeze the bite wound Rapid transport to Hospital, with the Rapid transport to Hospital, with the
bitten limb immobilized.bitten limb immobilized. Pressure immobilization only in cases Pressure immobilization only in cases
of elapid bites to slow down the of elapid bites to slow down the neurotoxic effect.neurotoxic effect.
2. Hospital Management2. Hospital Management
a.a. General MeasuresGeneral Measures♦ Look out for symptoms and signs Look out for symptoms and signs
corresponding to the different types of corresponding to the different types of venomous snakes.venomous snakes.
♦ Monitor the following parameters Monitor the following parameters regularly (if type of snake is regularly (if type of snake is unidentified):unidentified):
♦ Local tissue inflammation, Ptosis, Local tissue inflammation, Ptosis, speech, tongue protrusion, breathing speech, tongue protrusion, breathing pattern, petechiae, bleeding from pattern, petechiae, bleeding from venepuncture site, haemoptysis, gum venepuncture site, haemoptysis, gum bleeding, muscle pain, muscle bleeding, muscle pain, muscle weakness, colour of urine (for weakness, colour of urine (for haemoglobinuria), urine output and vital haemoglobinuria), urine output and vital signs.signs.
♦ Observe for at least 24 hr even if no Observe for at least 24 hr even if no sign of feature of venomous snake sign of feature of venomous snake bites detectable clinicallybites detectable clinically
InvestigationInvestigation1.1. Full Blood Count (FBC)Full Blood Count (FBC)2.2. Platelet countPlatelet count3.3. GXMGXM4.4. Coagulation time :- PT/PTTCoagulation time :- PT/PTT5.5. BUSE/ Sr. CreatinineBUSE/ Sr. Creatinine6.6. Creatinine Phosphokinase (CPK)Creatinine Phosphokinase (CPK)7.7. Urine for haemoglobinuriaUrine for haemoglobinuria8.8. ECGECG
b. Treatment of spesific snake biteb. Treatment of spesific snake biteI, Hydrophidae:I, Hydrophidae: When systemic poisoning occur ( Signs & When systemic poisoning occur ( Signs &
Symtoms of neuro and myotoxic :- Give 2-4 Symtoms of neuro and myotoxic :- Give 2-4 ampoules of sea snake antivenom IV with ampoules of sea snake antivenom IV with the earliest sign of systemic poisoning.the earliest sign of systemic poisoning.
Apart from antivenom, treatment of Apart from antivenom, treatment of hyperkalaemia, Ranal Failure (Resp. muscle hyperkalaemia, Ranal Failure (Resp. muscle paralysis) have to institutedparalysis) have to instituted
Judicious use of IV fluid, diuretics, Judicious use of IV fluid, diuretics, Bicarbonate, Insulin and dextose to correct Bicarbonate, Insulin and dextose to correct electrolytes and to maintain a good urine electrolytes and to maintain a good urine flow to avoid renal shut down.flow to avoid renal shut down.
b. Treatment of spesific snake biteb. Treatment of spesific snake biteII, Elapidae:II, Elapidae: If the snake is identified then spesific If the snake is identified then spesific
antivenom is given.2-10 ampoules of antivenom is given.2-10 ampoules of antivenom is required depending on severity antivenom is required depending on severity and NOT Body Weight.and NOT Body Weight.
Pain relief and care of the bite area with ists Pain relief and care of the bite area with ists tissue damage must be meticulously tissue damage must be meticulously addressed.addressed.
III, ViperidaeIII, Viperidae If there is only a slight prolongation of clotting If there is only a slight prolongation of clotting
time without significant local bleeding or time without significant local bleeding or spontaneous systemic haemorrhage, no spontaneous systemic haemorrhage, no antivenom is required but the patient is kept antivenom is required but the patient is kept in the ward until clotting time is normal or in the ward until clotting time is normal or near normal. Fresh blood or frozen plasma as near normal. Fresh blood or frozen plasma as well as other blood products may be well as other blood products may be necessary to correct bleeding tendency.necessary to correct bleeding tendency.
Where there is evidence of significant Where there is evidence of significant systemic haemorrhage, also give 2-5 systemic haemorrhage, also give 2-5 ampoules of antivenom.ampoules of antivenom.
C. AntiVenomC. AntiVenomIndication for antivenom treatmentIndication for antivenom treatment Systemic envenoming:Systemic envenoming: Hypotension, shock, signs of CVS toxicityHypotension, shock, signs of CVS toxicity Ptosis, Ophthalmoplegia, Respiratory Ptosis, Ophthalmoplegia, Respiratory
paralysisparalysis Impaired consciousnessImpaired consciousness Spontaneous systemic bleeding, non-Spontaneous systemic bleeding, non-
clotting bloodclotting blood Dark urine (myoglobinuria or Dark urine (myoglobinuria or
haemoglobinuria)haemoglobinuria) Tender stiff musclesTender stiff muscles AcidosisAcidosis
C. AntiVenomC. AntiVenom
Local envenoming:Local envenoming: Swelling involving >half of the bitten limbSwelling involving >half of the bitten limb Rapid progression of swellingRapid progression of swelling
C. Anti-VenomC. Anti-Venom
I, Choice of anti-venom and dosage:I, Choice of anti-venom and dosage: If species is known: mono-specific If species is known: mono-specific
or polyspecific anti-venom should or polyspecific anti-venom should given.given.
If unknown species: Polyvalent anti-If unknown species: Polyvalent anti-venom should givenvenom should given
The initial dose: 2-10 ampoulesThe initial dose: 2-10 ampoules
C. Anti-VenomC. Anti-Venom
II, Method of giving anti-venom:II, Method of giving anti-venom: Test patient’s sensitivity to anti-Test patient’s sensitivity to anti-
venom by giving 0.2ml SC:-observe venom by giving 0.2ml SC:-observe for 30 min.for 30 min.
If no adverse reaction occurs,If no adverse reaction occurs, administer the required amount of administer the required amount of
anti-venom diluted in 200ml of saline anti-venom diluted in 200ml of saline or D5% by slow drip over about 1 hr.or D5% by slow drip over about 1 hr.
Adrenaline 0.5 ml of 1 in 1000 should be Adrenaline 0.5 ml of 1 in 1000 should be drawn up for treatment of anaphylaxis.drawn up for treatment of anaphylaxis.
Routine anti- histamine, SC adrenaline andRoutine anti- histamine, SC adrenaline and hydrocortisone may given prior of hydrocortisone may given prior of
infusioninfusion to prevent reaction to anti-venom.to prevent reaction to anti-venom.
For a patient with a known allergic For a patient with a known allergic history, two IV drips should be set up; history, two IV drips should be set up; one containing anti-venom, one containing anti-venom, hydrocortisone, anti- histamine and other hydrocortisone, anti- histamine and other containing adrenalines.containing adrenalines.
If there is no improvement after the dose If there is no improvement after the dose of anti-venom a repeat treatment an hr. of anti-venom a repeat treatment an hr. later.later.
D. Other measuresD. Other measuresi.i. Give analgesia/ sedation to relief pain. Give analgesia/ sedation to relief pain.
(Morphin or Diazepam if in severe pain).(Morphin or Diazepam if in severe pain).ii.ii. Anti-tetanus therapy should always be Anti-tetanus therapy should always be
given and a broad-spectrum anti-given and a broad-spectrum anti-mircobial administered in serious cases.mircobial administered in serious cases.
iii.iii. Do surgical debridement of blebs, Do surgical debridement of blebs, bloody vesicles or superficial necrosis if bloody vesicles or superficial necrosis if present.present.
iv.iv. Prepared Intubate if Resp. depression Prepared Intubate if Resp. depression exist.exist.
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